Reddish fluid leak

papaindigo · **Posted:** Wed Sep 23, 2015 10:06 am

If in fact the transmission cooler portion of the AC condenser is leaking why on earth would you go to the trouble of disassembling enough of the front end to get the AC condenser out of the vehicle to haul it in for a "welding" job that may or may not work never mind the hassle/expense of bleeding and recharging the AC system? Simply bypassing the OEM transmission cooler by installing an after market cooler is a relatively simple ca. 1-2 hour DIY job that costs on the order of $50.

hgrimberg · **Joined:** Mon Dec 19, 2011 11:03 pm **Posts:** 363

papaindigo wrote:

If in fact the transmission cooler portion of the AC condenser is leaking why on earth would you go to the trouble of disassembling enough of the front end to get the AC condenser out of the vehicle to haul it in for a "welding" job that may or may not work never mind the hassle/expense of bleeding and recharging the AC system? Simply bypassing the OEM transmission cooler by installing an after market cooler is a relatively simple ca. 1-2 hour DIY job that costs on the order of $50.

First of all, I have a question: My understanding is that the radiator refrigerates both the transmission fluid on the lower part and the AC on the upper part. So when you all say "transmission cooler" do you mean the lower part of the radiator?
And second, the radiator has a fan on the front. If I install an auxiliary afternarket cooler or "radiator", this one wont have a fan to ventilate it, so it wont be a good replacement for the existing and damaged radiator?

thermorex · **Posted:** Wed Sep 23, 2015 10:39 am

If you install a custom Trans cooler on the side of the electric fan, then it will still be cooled by the viscous fan. The electric fan is used more for the Ac, not to cool the transmission side of the radiator. Adding such a cooler will work if you don't do any crazy towing for extensive periods of time. Otherwise, you'll need a bigger Trans cooler anyways, which may require removing the electric fan and replace that with a bigger Trans cooler and custom smaller fans, each on the side of the hood latch.

papaindigo · **Posted:** Wed Sep 23, 2015 11:10 am

let's get the terms, at least as they are used on this side of the pond, straight. At the front end of a CRD with an automatic tansmission (I'm not sure about one with a manual transmission) there are 3 "finned" assemblies - 1) intercooler which cools air compressed by the turbo and feeds it to the intake; 2) radiator which cools the engine coolant and feeds it back to the engine block; and 3) AC condenser with a transmission cooler in the bottom which does 2 things a) cools the hot AC gas and feeds it back to the AC compressor and b) cools automatic transmission fluid and feeds it back to the transmission. The AC condenser/tranny cooler assembly does not refrigerate anything.

The electric fan just behind the grill, as with all AC equipped vehicles I've seen, is there solely/mainly to provide extra airflow past the AC condenser and is triggered on by switch(s) in the AC system. It only incidentally provides a bit of air flow across the radiator and intercooler. How much of that air flow goes past the tranny cooler portion of the AC condenser I don't know but it's not much as the tranny cooler is in the bottom of the AC condenser. FYI it's only a small portion of the bottom no where near 1/2.

As I've suggested I consider it a total waste of effort and money to go to the trouble of attempting to fix or replace the AC condenser if you have a leak in the tranny cooler portion of it. Simply adding an after market tranny cooler and bypassing the OEM tranny cooler is and has been for decades the better solution.

Now if it was back in the bad old days of no AC with a tranny cooler located in the bottom of a radiator that was all solid copper which any decent radiator shop could fix with a bit of solder my advice would be different. Drain the coolant, pop 2 radiator hoses, undo 4 bolts holding radiator in place, drop by shop for say 30 minutes with $10-20 in hand for the fix, go back home and reverse the process.

hgrimberg · **Joined:** Mon Dec 19, 2011 11:03 pm **Posts:** 363

I searched on the parts fiche and I only see the radiator and the trans cooler but it doesnt talk about an intercooler as you can see in this figure:

So, is "intercooler" the term used in Europe for the trans cooler?
My mechanic says the problem is in the lower part of the radiator, which was what was shown on my previous photo of that oily radiator.
The radiator shop guy said he can weld it for $40.

PALiftedKK · **Posted:** Wed Sep 23, 2015 5:54 pm

PALiftedKK wrote:

thermorex wrote:

Radiator is aluminum. It has 2 holes in the bottom where some plastic fittings are inserted. I hope my memory serves me right... I deleted the stock cooler about 2 years ago and don't remember 100%...

But, it's not high pressure in those lines. At least not high enough to blow a transmission fluid hose and hose Clamps, and I'm telling you from my own experience of modifying every single Trans cooler in every car I owned. Dealer wants you to spend your money to them and it's using scare tactics.

If you don't want to spend too much money, I see 2 choices:

1. Get the fittings from a mopar dealer (online or brick and mortar). You change them. Or have a generic shop, comfortable with the work do it for you. Or:
2. Get e decent size STACKED PLATE Trans cooler. Cut the leaking metal lines as close to the stock cooler and use 3/8 uscg (marine) Trans lines and route them to your new stacked plate Trans cooler. Gates hose works too. You can find plenty write-ups in the tech section.

But, before you do this, go under the jeep and look. It's fairly easy to see if the lines are leaking. The stock Trans cooler is right at the bottom of the Ac condenser.

please check for yourself. :2cents:

we here still don't know your issue completely. all we know is your leaking trans fluid.

jws84_02 · **Posted:** Wed Sep 23, 2015 5:59 pm

Holy cow kid. Go out and actually look at your jeep. No, the inter cooler is its own unit and it is used to cool the intake air. It's the one that has 2 bigger, lets just say 3" for the sake of easiness coming out of it.

thermorex · **Posted:** Wed Sep 23, 2015 8:07 pm

hgrimberg wrote:

I searched on the parts fiche and I only see the radiator and the trans cooler but it doesnt talk about an intercooler as you can see in this figure:

So, is "intercooler" the term used in Europe for the trans cooler?
My mechanic says the problem is in the lower part of the radiator, which was what was shown on my previous photo of that oily radiator.
The radiator shop guy said he can weld it for $40.

I think that's the gasser cooling diagram anyways.

Lancer · **Posted:** Thu Sep 24, 2015 1:45 am

"So, is "intercooler" the term used in Europe for the trans cooler?"

No. For a start, most of the people who've tried to help here are American, but secondly the intercooler is NOT part of the engine OR a/c OR transmission cooling system; it is a part of the intake system, and cools the incoming air charge to the combustion chambers.

There will be no fluid leaking from the intercooler except, possibly, engine oil condensed out and which got into the system as part of the emission recirculation system.

Thirdly, that does look like the diagram for the petrol engine version of the KJ, not our CRD.

user113 · **Posted:** Fri Sep 25, 2015 2:05 am

I was not able to find a good drawing of the inter-cooler, the radiator and the AC condenser/trans-cooler all together in any of the manuals or parts lists, but trust me, there are three things all stacked up together in the front of the CRD.

If you look carefully, you can actually count them all. The rearmost one is where your problem likely lies, and I agree with the advice above to just stop using the trans-cooler in the AC condenser and use an add-on one like Thermorex shows.

You will not have transmission fluid leaking from the radiator in a CRD; just engine coolant. Additionally, the tanks on the radiator (for engine coolant) are plastic and cannot be welded.

hgrimberg · **Joined:** Mon Dec 19, 2011 11:03 pm **Posts:** 363

user113 wrote:

I was not able to find a good drawing of the inter-cooler, the radiator and the AC condenser/trans-cooler all together in any of the manuals or parts lists, but trust me, there are three things all stacked up together in the front of the CRD.

If you look carefully, you can actually count them all. The rearmost one is where your problem likely lies, and I agree with the advice above to just stop using the trans-cooler in the AC condenser and use an add-on one like Thermorex shows.

You will not have transmission fluid leaking from the radiator in a CRD; just engine coolant. Additionally, the tanks on the radiator (for engine coolant) are plastic and cannot be welded.

Ok, so it seems that what I have to fix welding is the transmission oil cooler which is somewhere in front of the radiator. I live in a third world country on the southernmost tip of the world so I wont be able to find an aftermarket generic trans cooler. Only thing I will be able to find will be transcooler for other cheaper cars that will most likely not fit. So I think the only solution will be to weld my existing trans cooler.

hgrimberg · **Joined:** Mon Dec 19, 2011 11:03 pm **Posts:** 363

The mechanic finally found two holes on the trans cooler so he welded it.

PALiftedKK · **Posted:** Wed Sep 30, 2015 2:27 pm

jws84_02 · **Posted:** Wed Sep 30, 2015 3:06 pm

PALiftedKK wrote:

Lol

voodooone · **Joined:** Tue Mar 06, 2012 11:13 pm **Posts:** 38

i understand i'm resurectiog a thread but is this a job(changind the lines)
i can do in my driveway ? I have the hability to jack 4 wheels and get a good foot and 1/2 to work under. :grim:

hgrimberg · **Joined:** Mon Dec 19, 2011 11:03 pm **Posts:** 363

I fixed the lower part of the radiator that was leaking which was actually the transmission cooler but now the gears are shifting hard. In very hot days and after driving more than 30 miles, my gears don't automatically shift specially when driving at more than 2000 rpm.
So, I think the problem is again on the transmission cooler. I think I should have replaced it with an external cooler. Should I install an external electric fan as well or if I am not planning on hauling anything, that is not necessary and just the external cooler will suffice?
Which external cooler would you recommend? A Derale 13502 Series 8000 Plate and Fin or a Hayden 678 Rapid-Cool Plate and Fin? Again, I won't be towing anything.
Thank you.

user113 · **Posted:** Mon Sep 24, 2018 10:37 pm

Cool transmission fluid is never a bad idea. If it were me I would get one with a fan, preferably a thermostatically controlled fan.

The steel coolant lines on my Jeep just rusted out and started leaking last week. The salt they put down here in the winter now is very corrosive. Much worse than the salt they used a few years back. My mechanic couldn't get the lines off the cooler either, so he ended up replacing both lines and the cooler. My transmission cooler is integral with the air conditioning condenser, which is a really silly idea. So I had to pay for the A/C service as well. I recently sprained a ligament in my knee, so I couldn't fix it myself; otherwise I would probably have just gone with an aftermarket thermostatically controlled fan cooler.

Mucho dinero, if you know what I mean. But cheaper than a new car...

Reddish fluid leak

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