front pump seal and bushing question

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trudysduster

trudysduster

FABO Gold Member
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well warm weather is around the corner and it is time to get the Duster out again. I was dealing last year with a problem with a leak from the tranny when it sat overnight. I replaced all the seals on the kickdown and throttle shaft and the dipstick tube. I am now going to pull the tranny and replace the front pump seal. Question is do I need to replace the front pump bushing. If so what does that entail. The torque convertor is new. I put it in last year when I did the resto. just did some research and somewhere it said to replace the bushing. never did that before and not looking forward to doing it if necessary. what is a rookie getting into here. Thanks,Bill
 
The pump seal can be changed without removing the pump. The bushing requires you to remove the pump and I took my pump to a shop where they own a press to drive out the old one and install the new one. I can't remember if you have to disassemble the pump housing but if you do, and have a 904, you will have to remove the input shaft assembly and valve body so you can temp install the pump in the case, then torque down the two pump housing halves, then remove the pump so you can install all the guts. Giant pain. 727's have a different style pump and don't require this.
 
both 727 and 904 need the pump disassembled to remove and replace pump bushing..

you a bushing driver to drive out the old bushing and drive the new one in...and then you need to stake the pushing so it does not spin
 
I chased a leak around. I replaced the shifter seal, changed the lines, and crawled under there with a can of carb cleaner. That is when I found out it was my pan. I bought one of those stamped deep pans and ended up using 2 gaskets to make it seal. I have a friend that had the same problem with his B&M aluminum deep pan. He ended up using 2 pan gaskets. I thought I would throw that out there as something to check before you pull the trans.
 
Another thing, the front seal shouldn't leak fluid just sitting overnight, it isn't submersed in atf. Unless it is residual leaking out from the previous drive. It could be the pump to case gasket. Or the plug for the kickdown lever rod.
 
this thing does not leak at all while running. it is only leaking when I bring it home and let it sit overnight. i have changed the pan. I have changed the pan gasket many times using silicone only, using silicone with new gaskets. using new gaskets without silicone. I used cork gaskets. I have used rubber gaskets. I have tried all of it. I changed throttle shaft gaskets, kickdown seal. Dipstick tube o ring. when i put it up on jack stands over night, the fluid is eaking out around the inspection cover. The pump seal is the only thing left I know to replace. when I pull the cover and run my finger up around the inside of the bottom of the bell housing, I get fluid. I am planning on putting this car in the Calvacade of Customs car show next January in Cincinnati and I dont think they would approve of a leak on the floor while it sits overnight there. It would embarrass the hell out of me also. I may have to replace the tranny. I have dealt with this all last summer. Any other ideas from anyone. It will leak out a puddle about 12" in diameter overnight. I have even lowered the fluid level some. Someone has told me that it happens when the pump drains back into the pan overnight. Thanks,Bill
 
It happens when the converter drains back through the pump when sitting, and it will leak until the converter fluid level is down half way.
The bushing should be changed at the same time because the bushing is what holds the converter centered in the seal.
A lot of times the leak is actually caused by the bushing wear.
The bushing should be installed with red locktite and staked so it does not move.
Same with the seal (Locktite) so the seal can't pop out.

Aligning the pump halves can be done with a big hose style clamp(or more than one if need be.
Put the bolts in the pump loose, put the hose clamp band around it tight, then tighten the bolts. (This is what they use at the shops) but actually made for pumps.

It's best if you stand the trans with the pump facing up, but not standing on the output shaft which will screw with you when you put the pump back in because of the endplay will not let the pump seat. (the drivetrain will be pushed up)

It's not hard to do at all, and we can help, but I would def have a shop replace the bushing and seal because you really need the driver to get the bushing in there straight and tight.
 
Trans go has a nice fix for converter drain back in their "no yo-yo" kit.
 
I have decided to take this tranny out and have it completely rebuilt from convertor back to the tailshaft. I talked to a tranny shop today and he told me it would be down for 2 days and he would completely rebuild it for me. thanks FABO.
 
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