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Ever since I started spinning my motor to 7100+ rpms I have had some fluid that pushes out the vent when I **** pound my car. Right now I have a catch can on it.
I have heard that eventually gm started routing that line back into the transmission. How did they route it?
Could I drill a hole in the dipstick tube and put a nipple in to run the vent line to?
I know you've rebuild your trans.
which pump gasket did you use? GM has an "updated" gasket with extra paper gasket material over the vent. It does not block the vent, but it baffles it so that naturally slung fluid doesn't want to crawl its way into the vent.
If you used the baffled pump gasket, then a catch can as you have it is the best route to take.
2nd best would be the breather setup GM uses with the check valve up by the top bolt of the bellhousing
If you wish to route it back to the trans, I'd be thinking about closing that loop. If you feed the vent back into the trans somewhere, you've essentially blocked the vent and now you'll have all the issues that come with. Like blown out seals and dipsticks.
I'm not familiar with GM routing the vent back into the trans but that doesn't mean it doesn't exist.
Alrighty, ya...I may have read it wrong or interpreted it wrong where I saw gm routing it back into the transmission.
As far as the pump gasket, I guess I really wasn't aware there was a baffled version but after looking at the difference in versions this current build does not have the baffled version, my previous builds did have the baffled gasket and the fluid coming from the vent was a whole hell of a lot better at 7100 rpms then with the current non-baffled gasket I have right now.
Thanks much for making me aware that there is a updated gasket to help with the vent issue.
I will probably just rock the catch can until the next rebuild...... and there will definitely be a next rebuild lol.
I know you've rebuild your trans.
which pump gasket did you use? GM has an "updated" gasket with extra paper gasket material over the vent. It does not block the vent, but it baffles it so that naturally slung fluid doesn't want to crawl its way into the vent. I feel like I somehow NEVER learned about this (during all my years @GM)... The "newest/ updated" pump to case gasket was first produced in the 1980s-1990s. It is GM part #12337931.
The records show the original gasket and part number as #8642040 (units produced from 1981- April 1983).
The first revision in 1983 is gasket #8654143. The revision end-date is not published in the digital database for some reason (I would have to go hunt through the GM Library to find it).
Both of these gaskets look like the gasket in the lower position:
However the second and newest revision is the current gasket; part #12337931 (the fact that the part has a 8 digit part number (starting with a #1) and not a 7 digit; tells me is was created 1988 or later (and before 2001).
If you used the baffled pump gasket, then a catch can as you have it is the best route to take.
2nd best would be the breather setup GM uses with the check valve up by the top bolt of the bellhousing This should be GM part #15859984.
If you wish to route it back to the trans, I'd be thinking about closing that loop. If you feed the vent back into the trans somewhere, you've essentially blocked the vent and now you'll have all the issues that come with. Like blown out seals and dipsticks. This would NOT be a good idea... The vent/ hose assembly that you mentioned would be more ideal.
I'm not familiar with GM routing the vent back into the trans but that doesn't mean it doesn't exist. NOT on a production vehicle... Maybe on a Military ONLY or other specialty (NON-General Consumer production vehicle).
And it is not really a good idea anyway.
Mr. Marooney... I know I am never serious with you and constantly joke...
But on a serious note: please post the part number for the pump gasket that you are talking about for me.
Thank you!
You posted it.
With the picture. FIrst picture is the correct one and 2nd picture the top gasket is correct.
That extra "flap" of material is what I am calling the baffle here
I usually get transtec paper/rubber kits. They always include both pump gaskets. As well as both early and late valve body gaskets.
Its easy enough to use either pump gasket, and for a newer builder that looks at both, I think they would be inclined to use the one that doesn't look like it randomly covers a hole in the pump cavity.
I don't have/never have needed the GM part number for the gasket so I don't have it.
That top gasket is what I used in previous builds and what came in my paper and gasket kit. That bottom one in the picture is what I have in there now and it just didn't register and what was in the paper kit I got this time (nor did I even know).
The top baffled one absolutley makes a difference.
I have never seen the older gasket in the 4L60E Paper & Rubber kits. The older gasket (for some reason) is still in the 700R4 Paper & Rubber kits, and is not necessary to have them in the P&R kits. The updated gasket works for all of them.
What would cause pressure in the 4l60e? I ran my vent tube line vertically up behind the motor, then to a check valve then to my catch can (Pictures below). It's definitely more than just not using the baffled gasket imo after fluid pushed all the way up.
The catch can fluid is after about 20 min. of hard miles.
What was the transmission fluid temperature at that time?
What seems to be the hottest temperature that the ATF ever gets to?
What would you say the average temperature is?
What are you using as a cooler-system for the transmission?
If using a ATF cooler inside the engine cooling system radiator... How hot does the coolant temperature get to?
Do you have any noticeable ATF leaks?
What was the transmission fluid temperature at that time?
What seems to be the hottest temperature that the ATF ever gets to?
What would you say the average temperature is?
What are you using as a cooler-system for the transmission?
If using a ATF cooler inside the engine cooling system radiator... How hot does the coolant temperature get to?
Do you have any noticeable ATF leaks?
Fluid temps have not been above 170 degrees this season.
I am running braided steel lines into a big plate style cooler spaced 1/2 inch off the radiator. (Right where my ac condenser used to be)
Factory cooler bypassed. Temp sensor in the pan.
My temps have always been in check. I have only hit 200 a couple times and that was on a road course.
Possibly a pump issue? I suppose I should hook a pressure gauge up to it and make sure they are good. Previous to this build my line pressure was at 230 psi at wot.
It's possible you have a cross leak in the pump, IIRC the closest high pressure track to the vent is Converter Feed. The one's I've seen have cross leaks to the Vent Cavity in the pump expel quite a bit of fluid though.
Update: Don't know what this says but the only thing I did was flip flop my cooler lines going to the cooler and I have ZERO fluid coming out the vent. Cloged cooler line that got dislodged?
I don't know but didn't think it would matter what way the line ran with a stand alone cooler.
Update: Don't know what this says but the only thing I did was flip flop my cooler lines going to the cooler and I have ZERO fluid coming out the vent. Cloged cooler line that got dislodged?
I don't know but didn't think it would matter what way the line ran with a stand alone cooler.
just kidding lol, false alarm.
I will just catch can it until next rebuild.
06-14-2020, 06:25 PM
4l60e breather vent routing 
