99 Eurovan transmission fluid leak

[soissisc]

My 99 eurovan has developed a massive trans fluid leak. Like pretty much all of the sudden it is leaking 1/2 a qt in 40 - 50 miles. When looking under the van when I stop it appears to flow out from between the engine and trans part line. I immediately assumed a torque converter seal or worse.

So I have dove into the process of pulling the trans. I have the front end off and am about to remove the CV half shafts. I pulled the starter and the recesses in there look pretty dry. That surprises me. I figured the amount of fluid this thing has been hemorrhaging it would be pooled up in there.

It looks pretty dry. The gear on the TC and the starter look pretty dry. No fluid residue when I wipe with my finger.

So I pull the cover to access the TC nuts and studs and it looks pretty dry in there too. The flex plate is dry dry when I wipe with my finger, even on the OD of the flex plate.

Now the cooler on top (stock) looks all grimy and the divots in the top of the trans are full of trans fluid. Could this be as simple as a failed O-ring or a failed cooler? The underside of the van the whole way back is coated with trans fluid. There is a massive leak somewhere for sure.

50K miles ago I had the trans out and I cleaned it top to bottom and it was spotless and look at it now up there! I think I am going to pull the cooler and see if I can find a broken o-ring or figure out some way to pressure test the cooler for a leak.

Any other suggestions?
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[soissisc]

Cooler to transmission o-rings are present, not cracked, flat, and hard as a rock. It is hard to tell if one or the other were leaking.

Any ideas on how to test the cooler itself? It seems like I would need a female M12 fitting to NPT to thread a Barb fitting to air pressure.

Any suggestions would be appreciated.

Do those banjo bolts come out of the cooler?

Here is the top of the trans with the cooler off. I suspect the rear of the cooler was leaking or the o ring.

_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[xavior12]

Yes, the bolts come out and theres another O-ring on the top of each bolt.

Personally, I'd get rid of that exchanger and do an external cooler. much better for cooling. The exchanger on the top of trans is not that good of a cooler.

[Abscate]

Orings as hard as a rock?

They seal by being compressed to fill the gap between the flanges. If they are hard, they won’t seal.
_________________
.ssS!

[soissisc]

Yeah I think the o-rings are toast. I am going to start there.
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[mvaska]

a AT cooler/exchange leak is basically the only way AT fluid can reach the top of the transmission.

good thing you didn't completely remove the trans! just pop in a trans cooler (since you're in there and they come with better hardware) and tighten things up.

[soissisc]

Well, I replaced the seals and got it all buttoned back up and still leaking a lot. So back in I will go... and out will come the trans.
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[soissisc]

So I pulled the trans, replaced the seal, have the trans back in, and I am in the process of putting everything else back together.

A few notes:

1. VW, why studs on the torque converter? If they were bolts instead of studs snagging every thread on the flex plate, that thing would come out with the trans a lot easier!

2. When you unclip the shifter cable and take the 3 bolts out that hold the cable bracket - remember to lift the cable off of the shift lever on the trans... If you don't, it will remind you later. And on that note, that rear bracket bolt could have been a little bit easier to reach during reassembly!

3. I would probably just take the down pipe completely off next time, rather than just unbolting it at the cat, it gets tight when you move the engine far enough ahead to get enough room to slide the trans off. Those are copper nuts where the downpipe connects to the exhaust manifolds, right?

4. My bushing in the pump looked nice and felt tight. The seal surface on the t/c looked very good, and the seal looked like this. Was it this mangled just getting the trans out and the fighting the t/c studs through the flex plate? The seal itself is brittle and the seal lip just cracks off when you try to flex it. Nearly 200K miles and it called it quits.

Either way, the new seal is in, and here's to hoping that it fixes the leak once all of this goes back together...
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[soissisc]

In torqueing down the TC bolts, I used my handy dandy air cooled engine flywheel lock inserted into the starter hole, to hold the flywheel in place.

It is like it is made for it!?!
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[cleverdeer]

Did you ever sort the leak out? Did changing the seal fix the issue?

I just rebuilt the 01P in my 2003 Caravelle (Eurovan) but when I took it for a test drive it was pissing out ATF from the bell housing.

Figured I must have nicked the TC shaft seal on the oil pump when I was re-installing the TC.

Have just dropped the box for the second time and the seal seems fine. No obvious tears/nicks/splits.

Wondering if I hadn't torqued up the oil pump bolts to spec.

[soissisc]

Mine was fine for a couple of years and then started leaking again. It is not much though. Some say always replace the torque converter if you have the opportunity, although I did not. There are the locating sleeves that locate the engine to the trans. If you miss those, it will leak.

From what I understand, the TC fit to the bushing in the pump provides most of the seal, and the actual seal just keeps whatever gets past that from leaking out.

I am considering taking mine apart again sometime, and double checking the locating sleeves are there, and maybe replace the TC and seal. I have been kicking around replacing the pump and o ring for that, but I am a little uneasy about getting that deep. But how hard can it be?

You can pressure check your TC, I have seen some videos on youtube. They can leak when even brand new.

Do you have any advice on replacing that pump and oring?
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[subdewd]

Pump o ring is easy and if the trans is out might as well. Dont foget to rder the pump gasket too If I remember the bolts that hold the pump in when removed thread I to holes on the pump flange and push it out as you are tightening

[soissisc]

I am also starting to wonder after revisiting this thread if I have a leak at the cooler. I am going to check that out first. I know that it was all clean up there when I put it back together. Thank you for reminding me.

Is pulling the pump straightforward? I mean, nothing tricky on the install?
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[subdewd]

from your picture I would have bet the cooler or cooler o ring.
not anything special about the pump,no.

[soissisc]

At the time, it did not fix the massive leak. I replaced the lower o rings on the cooler but could never figure out why so much trans fluid up there. So I went on and changed the seal at the TC. I am going to look and see if there is a bunch of trans fluid on top of the trans again. I have the van in the garage doing some rust repair right now.

I will update the thread.
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[soissisc]

So I have been working rust repairs on the eurovan, and the pesky trans leak has sort of got my attention while it is all torn apart and on jack stands. The top of the trans is covered in trans fluid. Besides the cooler itself, is there anywhere up there that could leak? I am having a hard time seeing down in there, but it almost looks like there is a sensor or something to the right on the cooler (when facing the engine). I will try to get some pics, but man that thing is buried down in there. I thought about oil pressure switches giving out and leaking. Maybe something like that?
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[volkswagenrehab]

I think my 99 has the same leak and I was wondering the same think about the sensor. Where you able to find out where it is coming from?

[soissisc]

Not yet. I have been working on some rust repairs when I can, and it has been on jack stands for that, for... a few months (much to the chagrin of my wife). I am actually thinking about running it and getting one of those bore scopes that attach to the phone. Maybe I can see what is getting wet or drippy. There is a clean place on the trans under the front right side of the cooler, like maybe that is where the drip lands? All around that one sensor up there is pretty grimy. If I could get decent pictures I would post something but that is really down in there for my phone.

But all of the divots between the casting webs on top are full of trans fluid.
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[volkswagenrehab]

yeah that sounds exactly like mine. I wonder if it can be reached by removing the starter?

[soissisc]

I think pulling the battery, and then that partition beside the battery, that gives a little better access.

Still not great but better.
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)