EAS Compressor and Valve Block Rebuild

[p38arover]

I pulled my compressor apart today as it's been taking too long to pump up the reservoir.

The cylinder is a write-off being badly scored:

http://www.aulro.com/afvb/attachment.php?attachmentid=93746&stc=1&d=1431340207

However, a question I have relates to the reed valve inside the cylinder. Note the different lengths of the shims, the longer being the reed. What I don't understand is why the shorter shim is under the reed. Also, the longer reed has a definite curve in it, something the other compressor reeds don't have. I wonder if the reed has been bending excessively on the intake stroke - another reason why I thought the short shim should be on top.

http://www.aulro.com/afvb/attachment.php?attachmentid=93751&stc=1&d=1431340485

What makes me also wonder is the mark apparently left by the screw head on the shorter shim indicating it was, at some time, on top of the reed - which is what I'd expect. I checked two other old compressors and they are the same, i.e., short shim below.

Surely the short shim (I forgot to measure its thickness but it's only a few thou) would keep the reed off the opening?

Does anyone who has rebuilt a compressor recall which way around their's was?

[Rupert Prior]

the short piece does hold the reed away from the opening. i think it is there to bleed the high pressure away when the compressor stops, so it can restart without stalling.

[p38arover]

Thanks very much Rupert. That makes sense. I hadn't thought of that.

[davidsonsm]

From memory there's an O ring that sits in a recess that actually gets glued in. The O ring sits slightly proud. Last time I refurbed one i ended up at an O ring/seal outlet to source the correct spec.

[p38arover]

From memory there's an O ring that sits in a recess that actually gets glued in. The O ring sits slightly proud. Last time I refurbed one i ended up at an O ring/seal outlet to source the correct spec.

Yes, that O-ring is on the other side under the other reed valve.

Some repair notes say not to use any sealant with that O-ring yet the ones I've pulled seem to have silicone sealant in the groove.

[p38arover]

While I was at it, I rebuilt two more compressors - well attempted to.

One went fine, the other not so. The reed (that covers the O-ring) had been damaged by someone with a hammer and pliers. It was also missing one of the cylinder head seals. To add to that, the new cylinder wouldn't fit into the machined groove, it was a poopteenth to big in diameter.

I'm also rebuilding the valve block.

Today I was reassembling the valve block and I noticed the section of the block that has the NRVs and bolts on the main block wasn't machined flat. (See the following pic of the block to which I'm referring - stolen from PaulP38A's site).

https://www.aulro.com/afvb/images/imported/2015/05/481.jpg

It has a semi-circular groove from the cutter which passes under the solenoid O-ring. It's a manufacturing fault. For the moment I've taken the same piece from another valve block to rebuild this one. I'll try refacing the faulty item at a later time. I should have taken a photo while I had it off but I've refitted it to the other valve block. Maybe tomorrow I'll take it off again and take a pic.

I wonder if this groove has been a source of my issues with the EAS.

[p38arover]

Well, that was an exercise in futility! :(

There seem to be more air leaks within the valve block than before. I can hear air leaking from around the diaphragm end. The compressor isn't switching on - I suspect that's due to the pressure switch, it's the only thing that seems to control the compressor. But it was working before I pulled the block apart.

I tried running the rebuilt compressor directly from the battery but it's not pressurising the tank.

It all comes out again tomorrow.

Oh, and of course the T-pieces for the manual inflation system are now leaking since they have been disturbed.

I need it back on the road by Monday as it's booked in for a new windscreen and has to be taken to O'Brien's at Seven Hills.

Gaaaahhhhhh!

[PaulP38a]

Ron - give Andy a call. He should have some of the old HRA o-ring kits and air line fittings at his place or Bundalene's. I have some of course, but you won't get them in time.

Regarding the o-ring under the reed valve in the compressor, I use a dab of gasket goo to hold it in place.

Just wondering if your compressor cylinder sleeve was sourced from the east or west coast of the US by any chance? I tried a sample cylinder sleeve from the west coast crowd, and it lasted less than a week, so I never used them again.

Cheers, Paul.

[p38arover]

Thanks Paul.

I have another O-ring kit that I bought from Rover Renovations quite a few years ago. I also have some new T-pieces of much higher quality that were given to me by Mike Summerhill when he gave me his P38A. Now is the time to fit them. Mike also gave me an O-ring kit.

Re the compressor kits, no, I bought them from i6 Automotive in the UK, Range Rover P38 EAS AIR Suspension Compressor Piston Liner Seal Repair FIX KIT | eBay (http://www.ebay.com.au/itm/151418972434?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)

[p38arover]

Well, it's stopped raining, the sun is out so my spirits have lifted somewhat.

I've checked pressures and the tank and front air springs have held pressure overnight, the rear air springs have lost pressure - which is about where I was when I started this exercise.

Now to go and pull the valve block out again.

[p38arover]

I checked the temp sensor in the compressor and it's open circuit and that's why the compressor won't run. I don't know where that sensor is inside the compressor motor housing.

I swapped compressors with another that I'd rebuilt at the same time and it won't pump up the tank either.

Re the air leak I can hear, I'm pretty sure it's coming from the over-pressure blow-off (relief) valve. When the pressure drops, the hissing stops. I might swap it with one from the other valve block I'm about to rebuild.

I came across a document by Lee Bourgeois about the EAS and he suggested a test I've never done - spraying detergent solution around the solenoids. Sure enough, the inlet and outlet valve solenoids are leaking slightly even though I replaced the O-rings under the solenoids. It makes me wonder if the solenoids underneath are also leaking. We need a test bench to put air into the system to check for leaks before fitting a valve block back into the car.

Now I've got leaks from my manual inflation system fittings so I need to replace their O-rings. Unfortunately, the O-rings in the EAS kit don't fit them. Hopefully, I can get some O-rings tomorrow. I know it's unlikely but I need the car mobile on Monday.

[daf11e]

Will any of the o rings from a valve block fit as I have a spare with o rings in it....I'm probably not far from you near Castle Hill.

[p38arover]

Thanks for the offer, Daf. :)

I have a couple of spare O-ring kits so I'll pull the block again tomorrow. :(

[daf11e]

No worries anytime....

[DT-P38]

We need a test bench to put air into the system to check for leaks before fitting a valve block back into the car. I am getting de-ja-vu...
I reckon you should build two of these proposed "test benches".

Keep one up there and do rebuilds for the NSW and QLD markets and send one to HRA (I will buy it) so we can cover the remaining States needs!

:-)

[p38arover]

Success! Well, mostly.

I still have a small air leak from 8mm line that plugs into the port below the silencer. I have trimmed them back but owing to their bends I can't go too far. I'll buy some 8mm line and see if I can make up some new bent lines.

I pulled the compressor apart and swapped the cylinder and piston from one of the UK kits that I'd used on the compressor that has a faulty temp switch.

The leaking rear right line was traced to a slightly damaged O-ring on the solenoid - see the central very thin O-ring in this pic of PaulP38A's.

https://www.aulro.com/afvb/images/imported/2015/05/290.jpg

Paul does warn about damaging them on his valve block rebuild page EAS Valve Block Rebuild Guide | PaulP38A.com (http://paulp38a.com/range-rover-p38/eas-valve-block-renew/).

Naturally, it had to be one of the solenoid valves on the underside which meant the block had to be completely removed - yet again. I'm getting quicker. :D

I'm watching the car to see if it drops on any corner. I've disabled the EAS to stop auto-levelling.

[p38arover]

Oh, the noise I thought was air leaking from the relief valve must have been coming from the solenoid valve.

Here it is 10:45 pm and the car is still up and still level. I'm not used to this!

[mtb_gary]

Well done Ron. Now you can sit back and watch the Monaco F1 GP

Gary

[PaulP38a]

I checked the temp sensor in the compressor and it's open circuit and that's why the compressor won't run. I don't know where that sensor is inside the compressor motor housing.


Thermal overload switch is on a PCB at the opposite end of the housing from the piston.
Switch is typically an AIRPAX 67L120.
Replacement guide here http://hardrange.com/downloads/manual/HRA-ThermSw-Install.pdf

[p38arover]

Hmm, I wonder where I'd get one of those....?

[FANTOM P38]

Well, that was an exercise in futility! :(


I need it back on the road by Monday as it's booked in for a new windscreen and has to be taken to O'Brien's at Seven Hills.

Gaaaahhhhhh!

Hope they quoted you a fair price on windscreen Ron I was quoted $750 for a non heated screen by my Local O'briens and ended up buying from my local mobile windscreen guy for $250.

[FANTOM P38]

It makes me wonder if the solenoids underneath are also leaking. We need a test bench to put air into the system to check for leaks before fitting a valve block back into the car.



Ron I had similar issue, so to test solenoids underneath I removed valve block from mounting box and then reconnected everything back up. This way I could tilt valve block while it is operating in vehicle and spray solenoids underneath to check visually for leaks - it worked and verified which was leaking, hope this helps, I know its a bit of mucking about but it worked for me. Then you just disconnect & remount back into its box.

[p38arover]

Hope they quoted you a fair price on windscreen Ron I was quoted $750 for a non heated screen by my Local O'briens and ended up buying from my local mobile windscreen guy for $250.

Thankfully it was by insurance - I have windscreen cover. AAMI booked the job with O'Briens. To give then their due, I had a call from O'Briens withing 2 minutes of submitting the claim form on line.

It's good being able to see out of the screen when heading into the arvo sun.

[p38arover]

Ron I had similar issue, so to test solenoids underneath I removed valve block from mounting box and then reconnected everything back up. This way I could tilt valve block while it is operating in vehicle and spray solenoids underneath to check visually for leaks - it worked and verified which was leaking, hope this helps, I know its a bit of mucking about but it worked for me. Then you just disconnect & remount back into its box.
Thinking about it, once the compressor and valve block are removed, it's quite easy to remove the box all together. Then one could mount the works back in place and test.

i found a good use for the EAS disable switch I fitted. On the way to Windscreens O'Brien this morning the compressor couldn't pump up the tank to pressure (the 8mm air line directly below the silencer and which goes to the dryer had come partially out). I was on the freeway so I couldn't fix it, so I stopped, popped the bonnet, flicked the switch to OFF, and continued with a partially inflated suspension. Had I not done that, the EAS would have gone into fault mode and dropped the car to the bumpstops. When I got off the freeway, I stopped at a servo and pumped the air bags up (leaving the EAS off).

I fixed it when I got home. The O-rings in the kit for the 8mm lines weren't quite right so the air line wasn't going into the O-rings. I fitted new correctly sized ones and was able to get a good seal.

[p38arover]

Gahhhh!

Over the past few days the tank hasn't been holding pressure and the compressor has been running continually.
Fortunately, I have an EAS disable switch so, after getting the car to height, I could switch the EAS off and drive on.

I wasn't able to find the leak until last night. When the air pressure reaches a certain point (about 130psi), it leaks quite noisily from the silencer. I suspect the diaphragm is leaking.

What's odd is that the car goes to high profile when parked with the EAS off.

I'm half tempted to cut the trip short as I don't want EAS failure so far from home. I do have my Nanocom and Faultmate with me.

[Keithy P38]

I rebuilt the compressor on my new P38 yesterday as it wasn't pumping (while I was out on a trip believe it or not), my cylinder bore was scored to the point it was chipping and had left a large amount of metal shavings throughout the compressors internals!

Luckily I had a spare cylinder and all is now well.

Good luck with yours Ron, I do hope it's only the exhaust and nothing more painful! I'd still do the trip if it were me. So long as you know a way around the issue your P38 is still very driveable!

Cheers
Keithy

[benji]

Ron have you got a set of manual over rides if the compressor goes?


Sent from my SM-G900I using AULRO mobile app

[p38arover]

I'm in Swan Hill so still moving forward.


Good luck with yours Ron, I do hope it's only the exhaust and nothing more painful! I'd still do the trip if it were me. So long as you know a way around the issue your P38 is still very driveable!


Ron have you got a set of manual over rides if the compressor goes?

I have manual inflation valves so, while ever the corner solenoid valves work, I can inflate either with my accessory compressor or at a servo.

But silly me forgot I have, on board, the Rovair I won back at the LR 60th Anniversary. I can disconnect the EAS ECU and control everything manually.

https://www.aulro.com/afvb/images/imported/2015/06/651.jpg

[DT-P38]

I'm in Swan Hill so still moving forward. I have manual inflation valves so, while ever the corner solenoid valves work, I can inflate either with my accessory compressor or at a servo. But silly me forgot I have, on board, the Rovair I won back at the LR 60th Anniversary. I can disconnect the EAS ECU and control everything manually.
Hi Ron, hope all is progressing... If you need anything BCC can express it to you anywhere in AU. AULRO "get out of jail card" discount applies.

Where would I get hold of one of those Rove-airs? Looks like a good bit of kit for HRA to (eventually) add to range.

[p38arover]

Thanks Dave. I should be home in a few days. I'm in Hay tonight.

Re the RovAir, I don't think Lee still makes them. I'd like one of his Mobilize units (NLA). Maybe he'd make up a batch of them.. See Labtronx Home (http://www.labtronx.com.au/home.htm)

[edc1967]

Hello.
I did a full repair service valve box, but
the left front wheel is low, check all valves and none have higher air leakage, also check the lungs and not lose, but not e able to review the
valves down, it is possible that the bottom valve is leaking.

Regards
Eugenio

[daf11e]

Eugenio if the front wheel was going down before the valve block rebuild then I would be checking the fron air bag for leaks at all levels.....if the wheel has started to go down after the rebuild I would be checking the o rings in the relevant solenoid.