Mysterious Transmission Leak?

[PJL]

I think CPF240 nailed it. In your picture of the starter where you wrote the word flowing is the transmission cooler line. It is on the right side. Right above the starter. Perhaps it chafed through. Clean that and have a look behind whatever that material is that's wrapped around it.

 

[RickTheEngineer]

I am starting to suspect that as well at this point. Especially since it didn't flow like that until a little while after the engine was running... Maybe to build pressure? Anyways, this whole time I thought that the cooler lines actually ran under the bell housing to the driver's side! I guess I'm wrong! (In the pictures I attached, 2 lines can be seen where the inspection cover/bellhousing is on the bottom of the tranny... Are those also the cooler lines? I just want to make sure! I'll take a closer look these next couple days)

 

[RickTheEngineer]

Also, those lines look like they are mostly steel lines, but a lot of the part numbers that come up show lines that are like 85% rubber... Can anyone confirm any part numbers that will work with the CUCV setup? Seems like on the internet I've found some variance in answers on this!

 

[86m1028]

A clogged breather tube will cause fluid to be pushed out of the dipstick tube.
My dad had a new 84-85 3/4 ton catch fire & burn because of that.
Trans over pressured & puked trans fluid all over the cat, it caught fire & burned the truck.
Gm then went to the flip over handle that helps seal the dipstick tube.

Agreed with others on here, pull, reseal trans & check breather.
Wouldnt hurt to replace modulator & all vac hoses.

A little side track but what did you end up doing about your lift kit ?

 

[Rvitko]

The lines are all metal and run across the bottom of the bell housing to the driver side. I have seen civy version illustrations that show rubber hoses to the passenger side. I suspect the metal lines extra long were a sort of additional cooler and unique to the military version. It could also be the lines or cooling in the radiator is clogged/kinked causing a pressurization.

 

[RickTheEngineer]

I see, I couldn't find anything like that online as far as parts go, and I tried making a couple calls and I managed to stump those who I spoke to from various auto parts stores. Do I replace them with rubber lines? I saw that you can just buy the fitting and do rubber all the way? I feel like that's not as good as steel lines though. But I ant find a part number for a complete line overhaul. If anyone knows it let me know! Also 86m1028, I removed all lift kit parts the other day and am getting ready to make a return. Now I am going to persue a shackle flip from ORD and do a zero rate to get the truck looking right. Also, getting a new driveshaft (double cardian with the slip yoke!)

 

[Rvitko]

If it was me, I would contact Hillbilly Wizard and buy them used. I have a feeling they add some cooling capacity and rubber would insulate. I have never found them available new. Other option would be a custom brake line company could make them if you sent in yours.

 

[RickTheEngineer]

I actually did look into Hillbilly Wizard but couldn't find anything! Yeah I was afraid of rubber being an insulator... I guess I could try to make those lines myself, I'd imagine it can't be too hard... Although I'd prefer buying it if there was such a thing!

 

[Rvitko]

Call or email him, great guy and he most likely has it. I needed the oil cooler lines and he had them.

 

[cpf240]

Look up the part numbers in the -20p or -34p TMs, then do a google search for them. They may be NLA though, unless someone has some NOS.

 

[RickTheEngineer]

Called up Hill Billy Wizard earlier, he said he doesn't have any and that they are a tough find sometimes. I am thinking about installing an after market transmission cooler (Rubber lines, but has a cooler you mount in front of the radiator) if I have to. They are pretty cheap. About $35. Now as for the diagram that I was looking at, it seemed as though all the lines go under the trans to the drivers side of the radiator and back the same way. I could not find any transmission lines that go above the starter, but I might be wrong. There was a steel line as was pointed out, but I am not thinking that was the transmission cooler lines, it was very very thin, like a brake line of sorts? Are there different lines that go to the trans? I did not think the diagram pointed out any lines that were leaking where mine was coming from! Ill keep looking around though. (I am talking about the 2 lines that I posted in a pic where they are running by the inspection cover/engine oil pan. Are those the only 2? Because they dont run above the starter!)

 

[rustystud]

If it was me, I would contact Hillbilly Wizard and buy them used. I have a feeling they add some cooling capacity and rubber would insulate. I have never found them available new. Other option would be a custom brake line company could make them if you sent in yours.

The steel cooler lines don't really add any extra cooling. There are there because the coolant pressure can reach 50 PSI and rubber lines are not all that strong and can be easily cut open or burst. There are plenty of companies that make steel or even stainless steel cooler lines for our truck . Just type in steel lines for 84 Chev truck. There is one company that sells stainless steel brake, fuel and cooler lines. Look them up under brake lines.

 

[Tinstar]

Another option is to just go with AN fittings and stainless steel braided hose.
Aeroquip makes everything you would need. There are a lot of different angle fittings that will make it clean and easy install.
I plan on doing that when its time.

 

[rustystud]

Another option is to just go with AN fittings and stainless steel braided hose.
Aeroquip makes everything you would need. There are a lot of different angle fittings that will make it clean and easy install.
I plan on doing that when its time.

That's what I did.

 

[RickTheEngineer]

I see all your points and I'm gonna seek out those options as big possibilities... I saw at autozone for like $35 they sell reinforced rubber lines that lead to a trans cooler radiator assembly that you mount in front of your coolant radiator... And you bypass/ignore a coolant radiator connection (made for the TH400). I liked that idea since it was a open and bolt up situation, although I like the idea of steel lines more. Can I ask a technical question though? After looking at the diagram and going under the truck, I noticed that the cooler line connections are on the passenger side on the upper 3rd of the tans right? Those were good side diameter lines (twice as thick as a brake line) and snake mother he bellhousing to the diver's side. But what was leaking was above the starter, and I think (not sure though) it was coming out of a smaller brake line size line any the starter. Where does that cooler line go or connect to? (It's in one of the pics I posted!) Thanks guys

 

[cpf240]

Perhaps it is the steel line for the vacuum modulator? Or the dipstick tube?

 

[RickTheEngineer]

I believe my dipstick tube is a large black steel line but that seemed dry... I didn't think of that actually... Is that line replaceable with just a brake line? Where does it lead to? I can't seem to find where it goes! (Didn't know fluid ran through that line actually!)

 

[cpf240]

Fluid should *NOT* run in the vacuum line. I'm just trying to figure out what else it could be. Perhaps if the vacuum modulator on the trans is bad, it can have fluid in that line, but I don't know. Maybe one of the guys with experience rebuilding the trans can chime in? Also, I added a diagram from the -20p TM to my previous post.

 

[RickTheEngineer]

I see the diagram, and it really looked like it was coming from hat region! It was above the starter and that line is definitely soaked, so I dont think that the thicker cooler lines go around that area... I guess it's still theoretically possible for it to be dipstick stuff but I'm very doubtful by this point since there's no signs of it running down it. Once I get the chance, I'm gonna fill the trans again and idle the truck and try to see where it gushes out of, it's just hard to catch since it happens so fast!

 

[Tinstar]

I would not totally bypass the radiator if you install a trans cooler.
Ok in summer, but not in winter.
Trans fluid needs heated up by radiator in winter to work properly.
Several threads on here About it.