New Radiator - Leaking !

[manic]

I've had a 200tdi DEF TDI radiator in for less than 5000km and it appears to have failed on me. :censored:

Here are the reasons I think it has gone so soon:
1 ) It was a ****-part aluminium one
2 ) The garage that installed it attached the electric fan with zip ties through the fins.
3 ) I'm the defenders unwanted friend.

The odd thing is that it had been sitting in the garage with no sign of a leak after a good long on/off road run last weekend. This weekend all I did was suck some coolant out of the expansion tank and radiator with a hand pump/syphon so I could connect up a heater matrix. I put the coolant back in and bled the system in the usual way.

I then went for a run around the block, temp guage was normal, heater matrix was hot, all pipes at correct temperature. No airlocks it would seem. I topped up the header tank and that was it job done.

Next day I go to the garage and there is coolant all over the floor! A pretty major dump of fluid.

It appears to be from the radiator fins. All plugs and hose connections around the radiator are good.

Coolant is visible along all rows below the zip tie
https://www.aulro.com/afvb/images/imported/2013/07/1025.jpg

So it looks like the zip tie as caused a stress fracture. I just find it odd that the leak came on so suddenly after I installed a heater matrix and bled the system. Perhaps pressure from air purge opened up a hairline fracture?

Bloody annoying! I had ordered a new fitting kit for the fan last week and was just about to sort out those blasted zip ties!

Any one know where I can get a good 200tdi Defender radiator (not a crappy ****-part one) for less than $400?

Also I've not removed the radiator before so welcome any tips/links on that procedure.

Cheers,
Matt.

[schuy1]

Faulty part, it is unlikely that zippy ties would cause it. However a garage that uses afore said to attach an electric fan should at the very least be whipped with brambles! and then banished from your list of preferred repairers! Doing it 1 self is bad enough without "pros" larking around .. Radiator removal is pretty self explanatory and straight forward..
Cheers Scott

[manic]

Yeah the garage that put it on was in UK. They were rushed for an export date. I'll forgive them, the priority was getting everything on the car so I could ship it. I should have sorted it out since.

I've drained all the coolant but there's the oil cooler lines which I'm unsure about - is a oil drain the only way to get them off without making a mess?

I plan to take the radiator to a rad shop for inspection. I'm curious to know what they make of it.

[schuy1]

Draining the oil will not stop the cooler lines leasking. There should only be a small amount in them, use rags under as you remove unions then elevate and plug ends. tie . Ah oki yeah so not a local job! :D
Cheers Scott

[frantic]

Just a suggestion but check all the screws and bolts as if they take so little care on the visible parts, the unseen ones could be worse. Be prepared to drill and re-tap the holes if they have either done it up to tight or worn the bolts and screws out. I had a reco 186 once that had oil leaking from the rocker cover , when I went to undo it 6 of the bolts had been done up so tight the heads snapped off when both myself or my mechanic tried to undo them. They had obviously used a powered shifter and done them up so the heads where 3/4 broken off the shaft!
I tend to agree that the fins are probably not designed to carry any weight and the fan should be attached to the frame otherwise the shock loading of a few speed humps will cause fractures over a short time.

[manic]

Thanks for all the input so far. I managed to remove the radiator and yes Scott it was self explanatory - 10 minute job once all the coolant is out :BigThumb:. I didn't drain the oil, it only weeps from the radiator when disconnected.

Anyway after it was completely empty and I had dried it off I placed the radiator level on it face and filled it with water to try and identify where the leak was coming from.

Amazing, under no pressure the coolant drops out of the core almost instantly. And not just in one spot, the whole lower center area of the core appears to be leaking.

https://www.aulro.com/afvb/images/imported/2013/07/691.jpg
That there was pretty rapid fire dripage. A large area of the core got visibly wet pretty much instantly as soon as water was poured into the rad. First drip was a couple of rows from a zip tie.

I cannot see any damage to the rails. How does a radiator suddenly fail like this? There were no leaks, one trip around the block and then this.

Looks like I will have to order in another new one. :mad:

Matt.

[DEFENDERZOOK]

take it to radiator specialist and see what he has to say......it might be worth repairing.........and cheaper than a new one.......

[jimr1]

take it to radiator specialist and see what he has to say......it might be worth repairing.........and cheaper than a new one.......
Hi Mat ,I agree with DEFENDERZOOK ,There are loads of rad repair workshops , in Melbourne get a few quotes just to see what your up for , then make a decision !!.

[rick130]

Stray current will eat through an aluminium core quicker than you can say 'pinhole', we've lost two Nissan patrol rads to stray current now.

All you need is a poor earth somewhere and your coolant path becomes conductive, aluminium is very reactive and so very quickly it eats out from the inside.

You've taken the rad out, but the easiest way to check for stray current is to use an old analogue meter with one probe in the coolant and the other on the earth terminal of the battery (a little hard in a Deefer, you need to extend the probe lead ;) ) start the engine and watch the meter.
Can't recall what is acceptable and what's scary in terms of +ve, but it doesn't take much.

[djam1]

Rick I have an expensive Allisport radiator I am about to put in a Defender is there an easy way of preventing this from happening?
eg can I earth the radiator and the head to the same place or something?

[rick130]

Duane, the main thing is to make sure all the earths are nice and clean and tight.

We ran a small wire from the rad support panel to the battery earth too, just to be sure on the recommendation of our radiator repairer.
Whether it actually does anything......

[manic]

Ah great, another thing to watch out for. I would never have guessed.

My earth straps are good, but this possibility makes me uncomfortable because I don't understand it.

Are you saying that if an earth strap to the engine is bad then anything that uses the engine as an earth will potentially get some negative current through the coolant from the radiator assembly? Or would it be a positive short to the radiator assembly that runs out through the radiator -> coolant -> engine...

:confused:

What about a faulty temperature sender/switch that sits in coolant?

My radiator sits on rubber grommets top and bottom theres a good chance it is isolated from the support that is ground to chassis by its mounts so if a positive short hit the radiator it would probably look for ground throught the coolant...


am I close?

:confused:

[goingbush]

Manic was there any chance the fan cable tied to the rad was electrically grounding on the fins , that would cause the problem, for sure.

in my old job they were anal about earth leakage

I would NOT earth the radiator , it should be rubber mounted / electrically isolated , And if you have one I would REMOVE your Low coolant level alarm , that puts a stray current into your coolant top hose, (the type that works by putting an electrical current into your coolant in the form of a metal probe in the top hose bleed hole)

The way I see it if the radiator is electrically isolated (rubber mounted) there will be no reason for it to become a sacrificial anode.

Earth everything else, over & above what LR do,

Landrovers are notoriously bad for Earth faults,
ever pulled an old Landy apart, the white powder that forms under a bolt head is aluminium oxide caused by electrolysis and it is an excellent electrical insulator, so just because an alloy panel is bolted to another metal part don't assume its earthed.
Ive got redundant earthing on mine in the form of a seperate earth bus that bonds the loom in various places, firewall, roof, guards, tub , chassis, engine, bullbar , gearbox, ECU & battery, At least I'll be OK if I get hit by lightning :D

edit, I just found this, interesting reading,

http://www.qldstreetscene.com/forums/topic/18015-electrolysis-and-aluminium-radiators/

[manic]

Excellent info in that post, thanks.

I do have a coolant level sensor in the rad plug that works on conductivity. And it is possible that the electric fan on the rad caused the issue with a short/current leak. Only recently the fan would go on but the indicator light would not.... Considering it failed so abruptly it may have been a hard and fast short when I was working around that area doing the coolant drain and top up. I'll be sure to improve the fan set up when I re-install.

Hopefully any coolant level sensor voltage in the system is negligible. Its a nice set up as it is and I'd rather not butcher my header tank with a float switch.
I'll find an analogue multimeter and do a current check with distilled water when I get a water tight rad sorted. I'll post results. There must be quite a few people on here with electric coolant sensors in their aluminium rads.

Maybe I should just get a copper core rad considering how rapidly an aluminum one deteriorates when current goes astray.

[rick130]

I would NOT earth the radiator , it should be rubber mounted / electrically isolated ,

Don, I would've thought the same except the Patrol rad was totally isolated, rubber mounts top and bottom off the plastic tanks and it went through.... :(

[schuy1]

Given that most alloy Radiators have plastic tanks which are in themselves insulators , Is it possible that the current,or some of it, is "leaping" from core to core? The fins may not be a very good electrical bond with the cores and that is how the electrolysis is "eating" the alloy away? This earthing game and stray current can do some strange things at times, and is not always predictable.
That QSS forum post has some very interesting information, even if some of it just commonsense.
Cheers Scott

[goingbush]

sacrificial anode ??

http://www.summitracing.com/parts/FLX-32060/


more info and a idea of what voltages are harmful, http://are.com.au/feat/techtalk/straycurrent.htm

and from the Jag club, some good info
http://www.jaguar.org.au/cooling-system-tips.htm

[goingbush]

Just out of curiosity I got my multimeter out

https://www.aulro.com/afvb/images/imported/2013/07/596.jpg
negative lead on block (for all readings)

positive lead on low level alarm terminal in top hose.

Alarm wire disconnected
engine off .01v
engine on .01v

Alarm wire connected , ign on 1.25v

now the unexpected result, ignition off
multimeter lead clipped to radiator core -ve 0.2v :eek:
with ign on the voltage polarity on the radiator core changed to +0.2v !!!
apparantly from reading links in prev post the safe level is .05v

the voltage on the radiator core was not affected when I disconected / connected low level sensor alarm wire

when I shunt the rad core to earth the voltage reading falls to zero

with probe in coolant reservoir .01v engine running

not sure what to make of these results

I still have the original (AFIK) alloy radiator with plastic tanks,
its electrically insulated via rubber mounts & when I replaced the hoses & coolant prior to this trip I inspected inside radiator (borescope) and it looks corrosion free

will leave well enough alone and wont be earthing the radiator core, to me this will give any stray current in the coolant a direct path to earth thru the core, and as there is voltage in there even with car turned off it will be eating away at radiator 24/7

[Blade74]

Wouldn't the radiator fluid which is mainly water be an earth straight to the motor??

[goingbush]

Wouldn't the radiator fluid which is mainly water be an earth straight to the motor??

not when we are talking millivolts, being able to measure a potential difference between the block and radiator core, even when ign is off demonstrates that
Good earthing needs a serious conductor.

if water was that good a conductor at 12v your battery would melt when you topped it up :)

[manic]

with probe in coolant reservoir .01v engine running



The tests suggest 0.05mv is the max reading for probe in coolant, so based on that your reading looks good. There is no mention of checking volts off the radiator core directly. I wonder if it makes a difference where in the coolant system you dip the probe? Would a dip in the header tank read differently to a dip nearer the low alarm sensor? If the coolant level sensor plunged 1.25v into the coolant you would would expect higher than 0.01v at the header tank no?

I think I must be a little bit dislektrik :confused:

[goingbush]

Agree with your synopsis, mutual confusion :confused:

( test descriptors I found show probe dipped into radiator cap on top of a radiator, do any cars have those nowadays ??)

the next closest best thing on a Td5 being the low coolant alarm tang, (close enough to top of radiator) which also reads .01v (which as you say is good)

basically I guess my readings can be used as a benchmark (good or bad) comparison

[manic]

I got the radiator back from the radiator repair place. He found leaks through out the center area of the core and said it was quite unusual. It cannot be fixed. The kind of damage indicated corrosion by electrical or coolant reaction.

I know the coolant has been a good 50/50, changed frequently with the same stuff. Nulon Green.

So I'm thinking it was a reaction sped up by my salt water episode earlier in the year. The radiator could have taken in a fair bit of super salty spray and held on to the salt even after a wash. If coupled with some stray current the core could get munched out pretty quickly, perhaps lots of tiny pits/punctures as a result and then the last air purge/bleed caused some pressure build up and pushed out the weak points.

The rad guy suggested a new copper replacement as the motor would have had originally. He said only small fractures on one or two tubes are worth repairing on aluminium cores. For that they have to use a special glue because of the plastic. Most of the time you need to replace the whole radiator.

So for me it will be copper, fixable out bush and less susceptible to stray current. I only hope the cooling is as good, the aluminum one was very effective. The thermo fan switch rarely kicked in and the temp gauge was rock solid on even the hottest day of the year whilst doing tracks in low range.

[rick130]

Get a Redback core, I'll dig the appropriate thread up. ;)


[edit] Here http://www.aulro.com/afvb/technical-chatter/166882-300tdi-radiator-rod-original-one-new-aluminium-plastic-one.html

[manic]

Get a Redback core, I'll dig the appropriate thread up. ;)


[edit] Here http://www.aulro.com/afvb/technical-chatter/166882-300tdi-radiator-rod-original-one-new-aluminium-plastic-one.html

Thanks, I checked out the redback site and it looks like they do custom cores. Can you order up a straight 200tdi replacement or is it a case of measuring up, specifying inlet outlet position/size, plugs position/thread etc. It sounds long and expensive.

I've been quoted 312AUD delivered on a bearmach aluminium rad, and 421AUD on a bearmach copper rad. Both from the UK, half that cost is postage. I'll be over there in a few weeks so I might just smuggle one back in my suitcase.

[rick130]

Your radiator bloke orders the core from Redback and fits it to your tanks.

They're heavy duty copper, designed for earthmoving equipment, etc. and made here.

[manic]

Oh I see. Thanks, but I don't want to pay more for a rad bloke to glue a redback core to my britpart plastic tanks. I'd rather get a full metal replacement if possible.

[rick130]

Oh I see. Thanks, but I don't want to pay more for a rad bloke to glue a redback core to my britpart plastic tanks. I'd rather get a full metal replacement if possible.


That wouldn't work, they solder the copper core to your original brass tanks ;)

I keep forgetting your ****part rad came with the car from the UK....:(

[manic]

Urgh... its gone again. Bearmach aluminium core = a little over 2 years.

Same kind of leak from the fins around the bottom corner. The electric fan was mounted to the frame this time, no zip ties through the fins but it was pressed up against the core. I also removed the low coolant probe and replaced it with a float switch in the header tank.

I will recheck for stray current, replace all rubber mounts and see if I can fashion up a proper shroud that moves the electric fan away from the core.

Oh and the next radiator is going to be copper core!

On the plus side I've been meaning to fit an aircon condenser in front of the radiator which requires the mounts to be moved back a little... so I would have had to remove the radiator any way....

But still, I don't want to be buying a new radiator every year or two!

Anyone else having issues with pattern part aluminium radiators?