D4 a/c not cooling

[Graeme]

My old D4 had a new genuine Denso a/c compressor fitted with the engine swap. The vehicle isn't being driven. Some time after the a/c was gassed with Hychil, the a/c was found to not be cooling at all but then worked very well as soon as a climate control fault was cleared, with the fault possibly caused by an earlier totally flat battery. Now a couple of weeks later, the a/c again doesn't cool.
Static pressure of around 89 psi rises to around 103 psi with the engine running. The pipes are basically ambient temperature and the evaporator temperature several degrees higher. The clutch is engaging when the a/c is switched-on. No faults are recorded. Being a new compressor, the assumption is that the flow control valve in the compressor should be OK. The connector for that valve is inaccessible so the effect of unplugging that connector can't be determined. Unplugging the pressure sensor connector causes several faults and when refitted and the faults cleared, the faults don't return. The battery was disconnected for 30 seconds to force a restart of the climate control ecu, but without any change.

Does anyone have suggestions of possible causes or tests to try please?

[BradC]

103 PSI is close enough to ambient at the moment. Have you put gauges on it? What is the low and high side? Unless they are close, I'd be inclined to look for a leak. Either the compressor isn't compressing or there's bugger all there to compress.

I did a recharge on our D3 just after we got it, which turned up a leaky service valve.

[Graeme]

Thanks for replying.
We don't have gauges. My understanding from the WSM is that the pressure indicates adequate refridgerant but we may have to get the pressure checked. There are no pressure faults, low or high.

We're confident that the compressor isn't pumping anything worthwhile but not being able to check the signal to the valve we can't tell if the compressor is or isn't being instructed to be at minimum displacement. That the system worked well some 2 weeks ago when last started, many months since the system was regassed, suggests that the fault is electrical/electronic rather than lack of refridgerant.

The 2 calibrations have been done and all the controls appear to work so I'm wondering if something such as WOT condition is met, which suspends a/c operation.

Does anyone know if the LR diagnostic tool can monitor the signal to the compressor control valve? The IIDtool doesn't have such an option.

[scarry]

If the compressor is definitely turning over and keeps operating,at those pressures,it maybe not pumping.

Are the High and low side pressures the same when the compressor is operating?.

Edit,Sorry Graeme,didn't see your post above.

[BradC]

Thanks for replying.
We don't have gauges. My understanding from the WSM is that the pressure indicates adequate refridgerant but we may have to get the pressure checked.


Not really. Refrigerant pressure is a P/T relationship between liquid and gas. There can be 2/10ths of **** all liquid, but as long is there is *some* the pressures at rest will be the same. So the D3 needs ~550g of refrigerant. If there was 100g of liquid the pressures would be the same at the same temperatures (at rest). If the compressor was running however there'd be not much on the high side and the low side would be in vacuum.

While it's nice the car gives a high side pressure, without a low side pressure you're a bit in the dark. Whacking a set of gauges on you should be seeing ~>200 psi high side and ~50psi low side. (Ambient +20-30c on the high side and ~4-6c low side).

[Graeme]

Thanks Brad for the education.

The 3.0 D4 2-zone WSM specs state 600g of R134A.

[BradC]

Graeme, I'd take it to anyone who does vehicle A/C and get them to put a set of gauges on. This is one of those things that need a bit of extra help/equipment to diagnose.

If it has a good charge and a buggered compressor you'll see not much pressure differential. If you see a good compressor and bugger all charge you'll see a massive difference. Either way, looking at the high side you might see the same thing. You really need to get a look at the differential pressure to have more of an idea.

Where the bloody hell is 4bee? He'd be all across this.

[Graeme]

The compressor is brand new and worked fine in cool weather 2 weeks ago. The pressures will be checked.

[DiscoJeffster]

Odd on you’ve got a leak. Refill with some dye will be the approach and track it down. Hopefully somewhere easy to resolve.

[BradC]

If it's Hychill you don't need dye. Just run around the unions and valves with a lighter or bubble fluid (Big Blu is my go-to). If it has leaked away over a couple of weeks, the leak will be big enough to spot. For bubbles, back it up with a couple of hundred PSI of nitrogen.

For a leak I'd put my money on one of the service valve cores, but I don't know what was removed and refitted to replace the compressor.

Why was the compressor replaced in the first place?

[Graeme]

The compressor was replaced for convenience while the body was off replacing the engine, as the orginal compressor had done over 300K kms and they're such a pain to replace with the engine in-situ.
The car is booked in for Friday with the mechaninc who gassed-up the new compressor a couple of months ago in the middle of winter, but now it's considerably warmer - well it was yesterday even though its winter again today.

[RANDLOVER]

The compressor is brand new and worked fine in cool weather 2 weeks ago. The pressures will be checked.

I agree with Brad and DJ regarding a leak. IME most new install faults are due to poor installation including lack of cleanliness during installation, which is why on the large systems I'm familiar with they are pressure tested with nitrogen before being filled, so I still favour a gas leak.

This brings me to my theory of why it it worked, failed then worked again. In my basic understanding of a/c it requires two shut off points to separate the low and high pressure sides, which I'd expect to be shut at rest, so it ran, then leaked half the gas (in broad terms) from the LP or HP side, resulting in an LP fault which was reset, ran again, shut down and leaked the other half of the gas, and won't cool now as the system is below the minimum pressure.

[BradC]

In my basic understanding of a/c it requires two shut off points to separate the low and high pressure sides

There are no real shut off points. The compressor is a non-return valve and in theory the TXV might/can shut down while idle. In practice they both leak and a system will equalize in short order. Even refrigeration systems with pump-down solenoids have leak rate specifications for the solenoids. Everything leaks, even brazed copper pipe.

In my case, I pumped out and re-gassed the car (it was 150g low) only for the missus to complain after a couple of weeks "The aircon is ****". Turned out to be the low side service valve that with hindsight I should have replaced while I had it open. I now just replace them as a matter of course any time I'm in there.

That reminds me, it has been about 5 years, I should probably do it again.

[RANDLOVER]

You raise an interesting point a few years ago I had my a/c pumped down measured and topped up as it was short of gas, after it stopped cooling a couple of times I'm not sure they replaced the schrader valves though, I'll have to ask my mechanic.

Regarding copper pipe leaking, the cheaper it is the better it leaks!

[DiscoJeffster]

As it happens I’m replacing the compressor, condenser and dryer on mine soon DIY. Will get it degassed, so the work, get it regassed. It has done nearly 400,000km. Figure it’s due. I will use genuine new seals and will do the schrader valves as you suggest [emoji846]
Getting the parts trade through Josh, a former member here, and borrowing his AC knowledge.

[Tombie]

My old D4 had a new genuine Denso a/c compressor fitted with the engine swap. The vehicle isn't being driven. Some time after the a/c was gassed with Hychil, the a/c was found to not be cooling at all but then worked very well as soon as a climate control fault was cleared, with the fault possibly caused by an earlier totally flat battery. Now a couple of weeks later, the a/c again doesn't cool.
Static pressure of around 89 psi rises to around 103 psi with the engine running. The pipes are basically ambient temperature and the evaporator temperature several degrees higher. The clutch is engaging when the a/c is switched-on. No faults are recorded. Being a new compressor, the assumption is that the flow control valve in the compressor should be OK. The connector for that valve is inaccessible so the effect of unplugging that connector can't be determined. Unplugging the pressure sensor connector causes several faults and when refitted and the faults cleared, the faults don't return. The battery was disconnected for 30 seconds to force a restart of the climate control ecu, but without any change.

Does anyone have suggestions of possible causes or tests to try please?

Passenger side wheel area.

Drop the plastic off the bottom front, reach in from there...

[Graeme]

We concluded that the connector on the compressor valve would be assessible but not the one at the wiring harness join which is on the engine side of the turbo intake tube. We had removed those little heat shields hoping to find that join.
I have a vague recollection that the compressor arrived fitted with new seals and there's an old a/c pipe join seal resting in the top of the exhaust manifold, suggesting that those seals were replaced in the regassing job.

[~Rich~]

Mine had leaks in all 3 pipe joins, 1 in the rear of the PS front wheel, 1 just behind the air tank and lastly up above the rear axle.
Replaced all the O rings, problem sorted.

[Graeme]

G'day Rich,
Fortunately no rear a/c in this case.

[Graeme]

High side pressure is low and low side is high, with a blockage suspected. Oil qty and refrigerant weight used are to LR specs.
The assessment is that the dryer which is part of the condenser is blocked.

[BradC]

Oil qty and refrigerant weight used are to LR specs.

I suppose there's about 240g of Hychill for the specified 600g of r134a?

[Graeme]

The message was that 600g was used, but perhaps the equivalent weight of hychill.

It was stated that there are no leaks.

[BradC]

Fingers crossed it's a blocked dryer and they didn't put in 600g of Hychill.

[Graeme]

I'll get that checked.

Edit: Would overfilling with Hychill cause damage?

[Graeme]

The mechaninc used the Hychill specs for the 3.0 D4 which is 600g R134A or 180g of Minus 30.

[scarry]

I'll get that checked.

Edit: Would overfilling with Hychill cause damage?

It would send the Head Pressure sky high.If the HP cut out is operating it should stop any damage,but better not to operate it at all,as cycling on the HP switch,and operating at very high head pressures is not ideal.
They are often set very high on Auto air systems,often just over 400PSI,which seems rediculously high for 134A/Hychill,but the settings seem the norm on many different brands of vehicles.

FWIW,our newer Hi Aces and Hi Luxs ACs operate on R1234YF

[BradC]

They are often set very high on Auto air systems,often just over 400PSI

The D3 doesn't throttle back the compressor until 479PSI. If my pt chart is correct that's about 90 degrees for r134a.

[scarry]

The D3 doesn't throttle back the compressor until 479PSI. If my pt chart is correct that's about 90 degrees for r134a.

:eek2:

In refrigeration we set 134 HP cut out on 240 to 260 PSI,even in a very hot day it will usually run well under 200PSI.
Cooler weather often 120 to 160PSI,particulary systems that are capillery,operating around -15 to -10 SST.

[BradC]

Then again your commercial refrigeration condenser will be in open air with the fan going flat out, not sitting up the arse of a diesel bus on a 42C day at the lights with the viscous fan doing less than 1000rpm.

I've seen > 26bar (~380PSI) sitting at the lights. Usually the evap temperature will start to climb so I'll lean on the throttle a bit to get the fan & compressor revs up. Happy to trade fuel for comfort.

[scarry]

Then again your commercial refrigeration condenser will be in open air with the fan going flat out.

Correct,but condenser coils on our gear get filthy at times,often with a big mat of dirt across them.
Usually found at sites where those customers think servicing is a waste of money.
Oh well,good luck to them,its the old story with anything mechanical,look after it and it will look after you.[smilebigeye]

[BradC]

Oh well,good luck to them,its the old story with anything mechanical,look after it and it will look after you.[smilebigeye]

When I was much younger I got a private tour of the WA Kwinana power station. The head engineer had worked for dad early in his career and was happy to give the ex-boss and his son a personal tour. He talked me through the shutdown and startup procedures for a generator and explained it was all about changing temperature slowly in order to look after all the metal. They even had auxilliary motors who's sole role was to keep the rotating mass slowly turning to prevent anything sagging. That was when I really learned about looking after machinery.

I've applied that across my life and it has served me well. Gentle warm ups, cool downs and maintenance. My son is picking up on that. Warm it up gently and let it cool down when you're done. Do the maintenance when it's due rather than when you think it might be needed.

I'm lucky enough to be able to be picky with my clients. Some of the buildings I work in I reckon you could safely eat off the plantroom floors.

[Graeme]

My son has discovered that the dryer is separate to the condenser even though 2012 Microcat doesn't show that it is on the D4 but does on the L322. This makes much more sense and should be much quicker and easier to change.

[DiscoJeffster]

My son has discovered that the dryer is separate to the condenser even though 2012 Microcat doesn't show that it is on the D4 but does on the L322. This makes much more sense and should be much quicker and easier to change.

Discovery 4 2010 - 2016 (l319) / Air Conditioning Condensr/compressr (3.0 V6 Diesel)((v)fromaa000001) | Jaguar Land Rover Classic Parts (https://parts.jaguarlandroverclassic.com/parts/index/part/id/22.52655.52722.27089/brand/land-rover/)

[Graeme]

Thanks.
There are lots of o/s suppliers but a Qld ebay seller has them. Furthermore a local proper a/c business might have one in stock a they fit lots of LRs and some Jeeps too.

[Graeme]

A general a/c question - is the system pressure when at rest a vacuum? The D4 dryer sealing doesn't appear to expect high pressure.

[shack]

The AC system pressure shuldn't be a vacuum.

When at rest it's normal for both the high side and the low side to be the same pressure, the differential occurs when the compressor starts pumping.

A problem than can occur on these is that if either the condenser or drier are blocked, the pressure on the high side can be much much higher than what the high low switch is reporting, this can lead to failure pretty quickly, and you'll never see the issue on the pressure switch.

My suggestion for anyone working on these AC's would be to just replace the condenser and drier together.

But I'm not an AC tech, however I have learnt a lot through failure!!

Mine and the car's.

[DiscoJeffster]

The AC system pressure shuldn't be a vacuum.

When at rest it's normal for both the high side and the low side to be the same pressure, the differential occurs when the compressor starts pumping.

A problem than can occur on these is that if either the condenser or drier are blocked, the pressure on the high side can be much much higher than what the high low switch is reporting, this can lead to failure pretty quickly, and you'll never see the issue on the pressure switch.

My suggestion for anyone working on these AC's would be to just replace the condenser and drier together.

But I'm not an AC tech, however I have learnt a lot through failure!!

Mine and the car's.

Exactly. Hence when I’m fitting my new compressor I’ve also ordered a dryer and new condenser. I figure it’ll be more efficient than the old, worn one, plus I won’t need to flush it. Win win. Do it once (hopefully).

[scarry]

The D4 dryer sealing doesn't appear to expect high pressure.

The drier is on the high pressure side of the sytem,similar pressure to condenser,while the system is operating.

[scarry]

I've applied that across my life and it has served me well. Gentle warm ups, cool downs and maintenance.

Exactly,i was thinking the other day,of all the vehicles we have had,over the years,including the business vehicles,which totals around 40,we have never had an engine issue,and very few other issues.Almost all the work vehicles did well over 300,000Km,before moving them on.Most had no repairs at all.
We serviced them ourselves,once out of warranty,but lately that has dropped off and some go elsewhere.
But we still keep a good eye on them and make sure everything is done properly,and on time.
We can't afford to have work vehicles off the road either.

[Graeme]

The drier is on the high pressure side of the sytem,similar pressure to condenser,while the system is operating.
Thanks Scarry.
I've just acquainted myself with a flow diagram - it's not what I prevously thought. However I don't understand how the low/input side of the compressor can be high and the high/output side can be low and that this is caused by a blockage in the system. Could someone please explain?

Edit: I just found this, so replacing the dryer is a logical 1st step. Presumably water vaporising causes excessive low side pressure.
With a faulty dryer, the moisture in the refrigerant would lead to lower pressure on the high side and higher pressure on the low side.

[BradC]

I struggle to see that myself. Moisture generally manifests by freezing in the txv/orifice tube. That would show as a high high side and low low side. Still, change the dryer and see what happens.

Generally a low high side and high low side would indicate a compressor that isn't compressing.

[scarry]

Generally a low high side and high low side would indicate a compressor that isn't compressing.

I presume these readings are taken while the compressor is operating?

Could be faulty or unloaded.

Or the internal high pressure relief valve has opened,but i don't think they use them in auto air compressors?

Like Brad said,moisture generally blocks off the TX,and can cause other issues.
Very often if the dryer is blocked,a temperature TD is evident across the dryer,even frost maybe seen on the downstream side.(of the drier).
And low side pressures are very low.The high side maybe high,or it could be lower than normal,as the Compressor is doing no work,depending on the system characteristics.

[shack]

How have you tested the pressures?

[BradC]

There's only one real way to test them, which is at the service valves. The low side is between the evap and the compressor and the high side is between the dryer and the txv in the same block as the high side pressure sensor. There are no service valves on the compressor on these (unlike my old volvos which made diagnostics a doddle).

[Graeme]

That means that a blocked dryer could cause the high side to be low. The flow diagrams that I looked at didn't identify the service valve locations and I assumed that the valves were on the compressor inlet and outlets.

[BradC]

That means that a blocked dryer could cause the high side to be low. The flow diagrams that I looked at didn't identify the service valve locations and I assumed that the valves were on the compressor inlet and outlets.

They aren't. If you have a look under the bonnet, the high side valve is on the passenger side adjacent the battery box in the pipework between the condenser/dryer and the bulkhead where it passes through to the TXV (which is somewhere inside the dashboard. Pretty much the point they started with and then built the car around).

[Graeme]

That sounds familiar. The vehicle is at my son's.

[scarry]

That means that a blocked dryer could cause the high side to be low. The flow diagrams that I looked at didn't identify the service valve locations and I assumed that the valves were on the compressor inlet and outlets.

Correct,i was assuming at the compressor as well.
When it is running is there any Temp difference on the inlet and outlet pipes of the drier.If so that is a sure indication it is partially blocked.
If not it can still be partially blocked,surprisingly.

[Graeme]

Only the temperature of the pipes at the valves was checked, where one might have been slightly cooler than ambient.

[Graeme]

The saga continues...

New condenser c/w dryer fitted and eventually regassed with Hychill. Cooling well and good pressures at idle but then the compressor appeared to cut out when engine revs were increased. No DTCs and the clutch is engaged. The mechaninc doing the regassing couldn't suggest a cause. Driving home, the a/c mostly didn't cool at all, but did for a short while after overtaking a truck.

Current indication is that powering the compressor's valve is now having no effect, presumably blocked at the valve or inside the compressor causing almost nil increase in pressure when power is applied. The resistance between the supply voltage and return pins at the connector next to the battery is 12 ohms which seems appropriate and confirms no broken wires. A clicking sound can be heard coming from the vicinity of the valve when applying 12V and earth to the pins, but only a couple of psi increase from the static 93.4 psi when the engine is running. Thus it appears that the compressor will have to be removed or at least the valve replaced if access is possible. Furthermore, it seems that I've damaged the ATC module as now there is only an extremely small duty cycle on the supply wire rather than the earlier nearly 100%.

I'm inclined to provide 12V to the valve and go for a test drive to see if the compressor again even intermittenty builds pressure before embarking on replacing the ATC and removing the compressor, which is quite a task.

[shack]

Reading this gives me PTSD!

[Graeme]

This morning the mechanic suggested contacting the compressor supplier regarding a possible warranty claim, seeing that it worked at idle but not when revs were increased.

I think its time to get a get of gauges to check both high and low sides before starting any work, as gauges cost less than the last pressure check.

[Graeme]

I'll tackle the compressor not pumping issue once the gauges confirm that the low side is the same as the high side before what appears to be the need to pull the whole dash out to get to the ATC module.

Maybe clutching at straws, I've monitored periodic 12V pulsing on the valve supply from the ATC module, as though the ATC might be looking for a pressure increase response after open circuit on the valve circuit or due to nil pressure increase for an extended period of time, so I'm not writing-off the ATC until the compressor is shown to build pressure with 12V on the valve.

[Graeme]

Gauges show high and low side pressures are identical whether the compressor shaft isn't turning or is turning and the valve is or isn't energised. Hence I assume that the valve is blocked which then raises the questions of from where did the foreign material originate and is there more floating around.

It appears from the WSM compressor removal instructions that there is little extra work in removing the compressor compared with just gaining access to the valve which would still be quite a task to R&R with the compressor so far away.

[DiscoJeffster]

Gauges show high and low side pressures are identical whether the compressor shaft isn't turning or is turning and the valve is or isn't energised. Hence I assume that the valve is blocked which then raises the questions of from where did the foreign material originate and is there more floating around.

It appears from the WSM compressor removal instructions that there is little extra work in removing the compressor compared with just gaining access to the valve which would still be quite a task to R&R with the compressor so far away.

The compressor is fun, yes. I took out the rad pack to give me extra access but you don’t need to. I also removed the power steering pump which sits over the top of it for extra room. Mostly accessible from the wheel arch and underneath.

[Graeme]

The WSM shows getting access via the wheel arch and although it doesn't state which way it is removed, I guess I'll find out.

[DiscoJeffster]

The WSM shows getting access via the wheel arch and although it doesn't state which way it is removed, I guess I'll find out.

Came out the front towards the rad, but again, I had heaps of space because the rad pack was removed, which meant all the turbo hoses were also removed etc.

[PerthDisco]

When changing or accessing the compressor also change the plastic fitting on the block water inlet above the compressor you’ll never get better access. It’s an absolute horror.

[DiscoJeffster]

When changing or accessing the compressor also change the plastic fitting on the block water inlet above the compressor you’ll never get better access. It’s an absolute horror.

And the hose that fits onto it too. Also near impossible to get at so also worth being new if you’re in there.

[scarry]

Hence I assume that the valve is blocked which then raises the questions of from where did the foreign material originate and is there more floating around.


It is reasonably uncommon,but i have seen driers break down and release material into the system.
This can also block the TX valve,or restrict it as well.

Maybe the valve,or the compressor,has just failed.

[Graeme]

The condenser c/w dryer are new, albeit made in China, so hopefully were clean.

[Graeme]

After gradually releasing pressure from the low side, the low side connection at the compressor was detached with quite a pop of pressure, but no obvious gas or oil. The high side connection was detached without any sign of pressure release. I realised that I hadn't connected the high side gauge so don't know if the high side pressure dropped at the same rate as the low side during the gradual release.

With the compressor out of the car, the control valve circlip was removed then the valve prised out with another quite a pop of pressure.

Why was pressure still on the low side and is it normal for pressure to be retained behind the valve with the 2 ports disconnected?

The screen on the valve has some oily residue. I haven't energised the valve to test for blockages as I'm looking for advice about the pressure releases before going any further.

Edit: I've inadvertently reverted to my originally incorrect assumption of the position of the high side test point in the circuit, expecting it to be at the output of the compressor which I now recall is not, as it is after the condenser and the dryer which is a new set. However that doesn't guarantee that the compressor is pumping, does it?

[Graeme]

Testing the valve...
Compressed air into a lower orifice with the other side blocked with a finger and the valve not energized, air exits from the centre gauze. When energized, the air exits very strongly from the upper orifices and no air appears to exit from the gauze. I suspect that the valve isn't blocked, but note that the stem inside the housing moves very little between energized and not energized.

Where to next? I'd like to have the compressor bench-tested.

[BradC]

Testing the valve...
Compressed air into a lower orifice with the other side blocked with a finger and the valve not energized, air exits from the centre gauze. When energized, the air exits very strongly from the upper orifices and no air appears to exit from the gauze. I suspect that the valve isn't blocked, but note that the stem inside the housing moves very little between energized and not energized.

Where to next? I'd like to have the compressor bench-tested.

This is a difficult one. The valve operates a cylinder in the compressor that moves a pivot on the swashplate to adjust the compressor displacement. I have ideas as to how you could test it, but you'd need adapters, a recovery machine, a recovery cylinder (liquid and gas valve) and some belt drive assembly to run it.

The valve is simple. It's a linear solenoid. With no voltage it'd likely have flow in one direction and no flow in the other (like a one way valve. The PWM is going to regulate the piston such that it controls the flow (high to low).

Where your're going to be ****ed is everyone is going to disclaim any responsibility because you used Hychill. Out of morbid interest are you using the original PAG oil or have you flushed and used something that actually lubricates? This won't matter, but it's more an interest thing. The other thing that really, really annoys me with HyChill is the charge volume.

Yes, Hydrocarbons transfer heat *much* better than R134a (because it's a **** refrigerant), so in theory you don't need as much in the condenser for subcooling, but HyChill specify stupidly smaller charge quantities vs Fluorocarbons leaving sweet **** all for leakage. All systems leak, and regardless of refrigerant. I do the calc's based on volume at 25 degrees C. That works out at more hydrocarbons from a volume perspective, but then it doesn't starve the evap, back up the oil and destroy the compressor.

[Graeme]

Charging was done by 2 different workshops with both using HyChill. The first stated that he used the correct volume of oil according to HyChill for the 3.0 D4 - that's all that I know.

I just watched a video on testing the valve with a balloon. However it appeared that the valve being tested only had 2 ports whereby the valve was closed or open, whereas this one has 3 and diverts.

Edit: The valve in the video clearly has the 3rd (upper) port, but not being a Sanden compressor I can't trust the result.

[DiscoJeffster]

Why did you use hychill out of curiosity and not just 134?

[BradC]

I use an equivalent to r134a (home made Hychill equivalent) because r134a is a **** refrigerant. Hychill is pretty much superior in every respect except acceptance. Hychill works with all oils whereas r134a requires specific oils it can transport. Because r134a is a terrible transporter of heat in a condenser, Hychill is even better and subcools excellently. So much better, which results in better cooling. Why wouldn't you?

[Graeme]

Why did you use hychill out of curiosity and not just 134?
My understanding is that R134A operators require a licence which general mechanics don't bother to get. It's also illegal to not recover R134A whereas HyChill is allowed to be vented.

[DiscoJeffster]

My understanding is that R134A operators require a licence which general mechanics don't bother to get. It's also illegal to not recover R134A whereas HyChill is allowed to be vented.

Both reasonable, thanks. I assume mine has R134 in it when it was refilled after I replaced it all. Thankfully mine has just worked.

[BradC]

Which is insane given your common "air horn" available at every joke, widget or marine shop uses r134a as the propellant. Also, a crap load of "freezer sprays", "air dusters" and general propellants. Can't use it in a refrigeration system (because fridgies have a good union and a Labor government), but can vent it to atmosphere cheaply and without penalty.

I got my last 5kg of r134a using a pile of cheap cans (on sale), a refrigerant recovery machine and a "can tap". I still use it in the cars it was designed for because most of them were designed for it from a Pressure/Temperature perspective and Hychill was designed as a replacement for R12. There are differences and if the system was designed for r134a then the pressure control can be a problem leading to evaporator freezing. My wifes old Golf was very pressure sensitive.

Now, it turns out the D3/4 isn't like that, I just haven't re-gassed it in a few years. Last time I did it I used r134a. Next time I'll use my "home-brew HyChill". I use a home made different blend that is closer to r134a on the Pt curve.

[scarry]

Can't use it in a refrigeration system (because fridgies have a good union and a Labor government), but can vent it to atmosphere cheaply and without penalty.


Union?What union do Fridgies have?
Who wants one anyway.[wink11]

It is a Class 2.1,highly flammable refrigerant,which is the reason.

Just imagine 10KG or so ending up in a cold room,as the evaporator is leaking,then someone walks in with a smoke.
Or a spark occurs for some reason where ever.

We use mainly R290 in newer self contained cabinets these days,which is part of the hychill cocktail.
There are very few new cabinets on anything else.
Great to use as it doesn't need to be reclaimed,and the volume of refrigerant in the system is a lot lower than 134,404,or whatever.
Although small commercial compressors that run on R290 are often difficult to source,and more expensive than an equivalent comp for R134a.

It runs with similar pressures to R22,but a lot lower discharge temperatures,which becomes an issue for heating up and evaporating condensate water.

[BradC]

Union?What union do Fridgies have?
Who wants one anyway.[wink11]

It is a Class 2.1,highly flammable refrigerant,which is the reason.

r134a is an A1 refrigerant. I can buy it in cans and blow it out all over the place, but it's illegal for me to put it into my car or marine refrigeration systems because I might spill a bit and haven't done an apprenticeship even though I have the gauges, recovery gear and leak detector.

[scarry]

r134a is an A1 refrigerant. I can buy it in cans and blow it out all over the place.

I am surprised,as i am pretty sure that is illegal,the EPA should be onto it.

[Graeme]

Research by son Justin has revealed that for this Sanden valve model, the top orifice is crankcase, bottom orifice is suction and middle is pressure. Neither pressure nor suction should ever be directly open to crankcase, but when energized, at least suction is open to crankcase and therefore pressure would also be open to crankcase. Therefore the valve is faulty. Presumably a shaft seal has failed and I wonder if the previous blocked dryer contributed.

Edit: It appears that my compressed air test into the low pressure port wasn't valid, as low pressure into the low pressure port was blocked when the valve was energized. The suspicion is that higher pressure from the air compressor overcame spring resistance to cause the valve plunger to move off its seat enough to cause the high pressure port to be opened to the crankcase port where high pressure vents when energized. Crankcase pressure is used to move the swash plate to a longer stroke position. However a new valve will be fitted anyway as the progression of the symptons from sometimes working suggest a failing then totally failed control valve and I can't rig a test of high pressure flow through the valve.

[BradC]

I am surprised,as i am pretty sure that is illegal,the EPA should be onto it.

Hahahahahahaha (gasp) hahahahahahaha (gasp) hahahahahahaha.

MG Chemicals 403A Super Cold 134, 400g Freezer Spray For Sale Online – Mektronics (https://mektronics.com.au/products/mg-chemicals-403a-super-cold-134-400g-freezer-spray?currency=AUD&variant=41045227831452&utm_source=google&utm_medium=cpc&utm_campaign=Google%20Shopping&stkn=3a4f90eee0ad)

CRC 2039 Freeze Spray 300g (https://alliedautoonline.com.au/products/crc-2039-freeze-spray-300g?variant=43849073393891&country=AU&currency=AUD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic)

It's only illegal if you put it in a refrigeration system and don't have a license. You can't get a license unless you've done a 4 year apprenticeship. Somewhere I have an E-mail from the federal minister at the time (2009) who pointed out unless I did the apprenticeship I couldn't get a license because I was living overseas when the grandfathering came in and missed out. She did point out I could go and see my local union to tell me where I could stop earning money for my family for a few years while I did an apprenticeship to get my license.

Turns out the Arctick only check on people who are licensed because unless you are registered with them they don't know where to check up on you, so all good.

[scarry]

Hahahahahahaha (gasp) hahahahahahaha (gasp) hahahahahahaha.

MG Chemicals 403A Super Cold 134, 400g Freezer Spray For Sale Online – Mektronics (https://mektronics.com.au/products/mg-chemicals-403a-super-cold-134-400g-freezer-spray?currency=AUD&variant=41045227831452&utm_source=google&utm_medium=cpc&utm_campaign=Google%20Shopping&stkn=3a4f90eee0ad)

CRC 2039 Freeze Spray 300g (https://alliedautoonline.com.au/products/crc-2039-freeze-spray-300g?variant=43849073393891&country=AU&currency=AUD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic)

It's only illegal if you put it in a refrigeration system and don't have a license. You can't get a license unless you've done a 4 year apprenticeship. Somewhere I have an E-mail from the federal minister at the time (2009) who pointed out unless I did the apprenticeship I couldn't get a license because I was living overseas when the grandfathering came in and missed out. She did point out I could go and see my local union to tell me where I could stop earning money for my family for a few years while I did an apprenticeship to get my license.

Turns out the Arctick only check on people who are licensed because unless you are registered with them they don't know where to check up on you, so all good.

That is amazing.
If i intentionally released any controlled substance,including refigerant,into the atmosphere i would be in more trouble han a serial rapist[biggrin]
That is if i was stupid enough to get caught doing it.

As for ARCTICK,they are the most useless mob on the planet.
Yes we like taking your money,and doing routine annoying checks,which a monkey could fudge,but that is where it all ends,unfortunately.

Same as QBCC,another absolutely uselss mob who have no idea what they are doing,all of a sudden we have to have a mechanical plumbing qualification.
FFS,i have to now go and do some training on what i have been doing for 45yrs?
It won't be happening.
****ing idiots.

Anyway,we should appologise to the OP,for getting off topic.....

[RANDLOVER]

Same as QBCC,another absolutely uselss mob who have no idea what they are doing,all of a sudden we have to have a mechanical plumbing qualification.
FFS,i have to now go and do some training on what i have been doing for 45yrs?
It won't be happening.
****ing idiots.

Anyway,we should appologise to the OP,for getting off topic.....

I don't think ignorance is going to be a viable defence when releasing pollution into the air.

Have you seen QBCC's flash new offices in the centre of town, nowhere to park, especially for tradie trucks or trailers. Seems like they want your money but don't want to see you!

[Graeme]

The new valve got the compressor pumping and the system cooling well when 12V was applied directy to the valve circuit, but no pressure with the valve controlled by the ATC ecu. A replacement ATC ecu is on its way.