A-904 Pump front seal replacement.

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Jax

Jax

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Hi,

During my last race a few weeks ago, we noticed that after a run we had trans fluid leaking from the torque converter / bell-housing area.

We assume is the front pump seal leaking. However the oil does only leak after a hard run pass on the track, not under normal driving or at idling.

I will drop the trans in the coming weeks to verify / inspect and replace.

Which store or parts supplier do you recommend when buying replacement seals and or gaskets? I.e. for trans overhauling?

Alex.
 
is the trans vent for the 904 up front? or is it toward the back on the tailshaft housing?
for some reason, I picture a piece of sheetmetal over an opening that acts as the vent.
 
Tnx guys... any recommendations where to purchase the seal?
 
Check the converter over real good too. If it's not a billet snout on the converter it may have a hairline crack. I used to work on forklifts and ran into one once that had a cracked snout and it only leaked under a full load. After first replacing the seal and seeing nothing wrong by the naked eye it still leaked so we took it back apart and rigged up a rubber seal on the converter snout and applied air pressure and found the leak down where it was welded together
 
Rock auto sells them.....I just bought 3 of them from the local trans supplier...14 dollars for 3 of them....about 4.00 each....

the vent is in the front...but i have never seen a vent leak on a 904.....I have left the pump bolts loose....and it leaked...lol
 
See post #5. Those 904 converters are some thin steel. They look thick, but if you stick your finger down inside, you will notice that they get thin right below the slots. I wish I knew why.
 
70aarcuda said:
Rock auto sells them.....I just bought 3 of them from the local trans supplier...14 dollars for 3 of them....about 4.00 each....

the vent is in the front...but i have never seen a vent leak on a 904.....I have left the pump bolts loose....and it leaked...lol
Click to expand...

Is there a possibility that fluid may leak via the pump vent? and if this is the case, what can be causing it? maybe oil overfill?
 
While you're at it, now is the time to also replace the pump gasket, the pump to case seal (large O ring) and the 6 front pump bolt washer/seal. If the front pump seal is replaced it's a good idea to pack it with Vaseline, as this helps prevent the garter spring from coming out. While inspecting the converter hub area, look closely at the welds around the hub. Might be an issue there.
Just a couple of suggestions.
 
Got 6 904 in use....5 of them with transbrakes not one has ever leaked from the vent.....but move it....its your trans...lol

Got idea to replace the pump gasket...o ring and pump bolt washers....easier went the trans out then pulling it again
 
pearljam724 said:
Where’s this vent located you guys mention ? On the passenger side of the case ?
Click to expand...
It's in the front pump. I haven't seen one leak there either unless it is over filled. The few cases I've read about vent leaks is under deceleration generally when you do a burnout then brake hard
 
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