new trans leaking..

[BeepBeepRR]

I just spent the entire day yesterday dropping the trans back out of the roadrunner to replace the input shaft seal in a hughes performance transmission. Thinking it was leaking there it doesnt leak when the car is running or for about an hour after its off. But you come back to look at it in the morning and there is a puddle on the ground. When I dropped the trans yesterday the pump seal seemed to be good to go with no leaks. I also installed a B&M torque converter when I initially put it together. I noticed the new converter came with a new seal. My thinking was that it must need that seal to work. So I dropped the trans yesterday to put that seal in. All was well but came home from work today to see a new puddle under the car. Its coming from the front of the transmission.

I am a little pissed at the moment because the exhaust H pipe runs just behind the trans. In order to drop it I have to take the entire exhaust loose from all the hangers just to get the trans out of the car. If anyone has any ideas as to why this thing is still leaking please help a man out.

New Hughes Performance 727 with deeper than stock pan.
New B&M torque converter.
9 quarts of trans fluid.

 

[AR67GTX]

When you say coming from the front I assume you mean its on the bottom of the bell behind the sheet metal closure? If so it might be the vent at the top of the pump. Mine blew a bit out of that or the front seal when I first started it up after rebuilding, but seems to have stopped. Have you looked closely at your fluid level after the transmission warms up. I'm running mine a pint low since I have converter leak down overnight.

 

[moes]

if you have the tranny overfilled with fluid and when it expands with heat after driving the car there is a vent hole above the front pump that will cause it to leak from. Check your fluild level with the tranny in neutral when hot on level ground. I rebuilt a tranny for a friend and he told me that it leaked from the front seal after driving the car and it sat over night ( converter leaked back abit ), I had him check the fluid level, it was over filled.

 

[HALIFAXHOPS]

LOL check if there is a bolt in the hole that SOME dipsticks use to be held in just above the pan, actually seen it not there a few times. Right Andy? @green 66

 

[BeepBeepRR]

The pan on the transmission is a bit bigger than stock. I checked the level today and its not even on the stick. The majority of it is on the ground under the car. I think the B&M TC might be the culprit. I spent an hour on the phone with Hughes today. They dyno test every transmission they sell he said. So my only option is to drop the trans again. Check the front pump seal and replace the converter with another one. I mean its not rocket science to put a torque converter in the transmission. So that's not the issue. I have an inspection camera I'm going to run in behind the converter tomorrow. Maybe i can see where its leaking from. I suspect its the damn converter. Brand new...

 

[oldbee]

Overnite? First thoughts are o-ring at fill tube or case seal where valve body shift lever comes up thru.

 

[BeepBeepRR]

Its leaking inside the bell housing portion of the transmission. Nothing external.

 

[oldbee]

Well then- t.c. seal or vent.

 

[BeepBeepRR]

Well then- t.c. seal or vent.

Same thing I was thinking

 

[HEMI-ITIS]

I put the vent on the tailshaft.When I had a hairpulling experience like that,the neck of the converter was CRACKED...........

 

[BeepBeepRR]

Im beginning to think its the converter. I will pull the trans tomorrow and see whats going on. I will return the Broken&Mangled torque converter.

 

[AR67GTX]

Well there's also the pump gasket(s) but if the pump is put in halfway carefully and the case is good it's hard to imagine them leaking.

If your really want to be 100% sure where it's leaking you could first put some dye in the fluid and use a UV light when you remove it again, to see if the origin is at the converter seal, the upper vent or the pump gasket.

 

[BeepBeepRR]

I have some AC dye and a UV light. Wonder if that will work? I have a small endoscope light I can shove up and in between the torque converter and the pump. I'll make a video and see whats going on in there.

 

[AR67GTX]

I would guess that it's the same stuff but it's pretty available at local parts stores if you don't want to risk it. I pulled, rebuilt and replaced mine last winter and I don't envy anyone having to do that 3 or 4 times over.

 

[HEMI-ITIS]

What you would see is fluid coming from the front of the vert.Can't tell if it's the seal or cracked neck.

 

[ckessel]

I know there is a difference between a/c dye and engine/trans/fuel dye but could not tell you what it is. Wash it down good, drop some dye in, drive it for a few miles, shut it off and start black lighting it. Let it sit for awhile if needed to verify where its coming from. Make sure you have some Zepplin or Doors playing in the background when the black light is going to further the ambiance. LOL!

 

[BeepBeepRR]

Well after spending my 4th pulling the transmission yet again. I think I have it solved. Its not the torque converter or its seal. Its the pump seal.

 

[oldbee]

Very weird, assume sealing washer behind the bolt?

 

[BeepBeepRR]

It looks like its coming from under the washer as well as the back side of that gasket.

 

[oldbee]

Maybe a 'nick' in the metal somewhere? Looks like more tearing apart to come.