1980 chevy k10 350/th350 fluid question

[LegoChevy]

What would cause the trans to push fluid out of the vent? I have changed fluid 2x and filter once. Within a month. It was pushing it thru the dipstick tube until I found on here that the vent being clogged will do that. I cleared the vent now it just blows it out there. I'm stumped I can't find anything on anyone having a problem like this. It seems like when it gets hot it makes a loud squealing noise when its about to turn into old faithful. People at work tell me I just need a new trans but mine shifts fine until it starts erupting fluid then I lose all of my gears, once it cools and drains into the pan it will shift like nothing ever happened until it erupts again. Does anyone know what needs to be done to correct this?

[timthescarrd]

Sounds kinda like it's boiling the fluid.  I would check your cooler lines to make sure they aren't blocked

[LegoChevy]

Sounds kinda like it's boiling the fluid.  I would check your cooler lines to make sure they aren't blocked

It has the factory style still running thru the radiator. The last time I had it running I felt the lines going into it and the supply was warming up with the trans but the return (on bottom?) Was significantly cooler. And it did sound like it was bubbling when I shut it off. Is there a way to clear them and should I run an after market cooler?

[timthescarrd]

You can disconnect the lines front and back and run compressed air through them, that will clear the lines themselves.  Compressed air is usually too much pressure for the ATF cooler/radiator though.

I would take off the return line first to see if you get fluid flowing out.  If it doesn't then there may be a clog in the ATF cooler/radiator. If ATF comes out, then take off the feed line, clear them both, and pour some ATF into the top hole on the ATF cooler/radiator and see if it runs out the bottom about the same rate. 

If antifreeze comes out of the ATF cooler/radiator.  Then you need to replace your radiator.

Aftermarket coolers are nice if you do alot of towing or moving heavy stuff, however the ATF still need to run through the ATF cooler/radiator first then into the cooler, then back to the transmission.

[78BIG-TEN]

Overheating or over full.Gm added a hose to the vent tube and a locking diptick to the 700 for that very reason.pulling heavy loads the fluid would overheat and blow out possibly causing a fire

[LegoChevy]

I bought a hayden after market cooler but I plumbed it in line not sequence. Should I plumb it in sequence with the radiator? I removed the return line at the transmission and started the truck and it was indeed moving fluid. So I don't believe there is a clog. It got dark thirty on me so I quit. I haven't been able to run the truck any since I installed the cooler. I have a full donor truck with a 4spd but I don't have the time to do the swap unfortunately. I'm just parting it out.

[Irish_Alley]

heat is what kills the trans so dont drive it till you fix the problem

[LegoChevy]

This problens is driving me insane. This truck was my dd. I have 4 vehicles and they all died at the same time. My integra is down with some kinda fuel pump/fuel pump wiring issue my frankenstein chevy a guy sold me with a fake title and I didn't notice until I was trying to get it legal my 80 is having the trans issue I just got it a month ago and my rx7 decided it was going to eat a seal.

[LegoChevy]

Well I still haven't figured this out. I'm gonna do another filter and fluid change. The trans is making a strange whining sound that changes with throttle. Wot its extremely loud. No throttle its quiet.

[LegoChevy]

UPDATE: The cooler alone seems to keep the fluid much cooler than before. I still haven't got to drive it yet but I'm still fighting the same problems. When it gets warm the transmission starts this awful loud squealing noise and I can't pin point it. It does it in all gears including park and retreat but only after it warms up. With throttle and acceleration it grows louder until it shifts then it starts "spooling" back up again. Usually when it starts squealing like that is when it starts gushing fluid.

Thanks for the help so far guys and gals.

LegoChevy

[LegoChevy]

UPDATE:: Well after a long road of pulling my hair out and inventing new words I finally got the trans fixed. There was water in my fluid at some point I'm guessing from before I bought it and it destroyed everything in the trans not to mention the mud/gunk they rinsed out of it. Now its got a fresh rebuilt th350 with a mild shift kit. Running great so far.

That's to those of you that offered your advice and knowledge on this issue.