Transmission replacement I have blown a front pump seal

ROBBIEMORRIS44

MEMBER
1988 CHEVROLET 1500
5.7L
V8
2WD
AUTOMATIC
200,000 MILES

I have blown a front pump seal in my 700r4 and I don't want to purchase a used transmission that is a short warranty gamble. I have been researching and purchased a completed manual on the 700r4. I have always done all my intermediate family mechanic work but complete rebuild of a automatic transmission is intimidating. They make a DVD on the build and with quality rebuild kit I still have a fraction of what most transmission shops charge. Opinions?

Monday, March 4th, 2019 AT 2:21 PM

4 Replies

ASEMASTER6371

MECHANIC
52,796 POSTS

Good afternoon,

If you have never done a rebuild on a transmission, you will need a good guide. ATSG makes a great guide for you.

You will need some special tools for the clutch pistons and the puller for the front pump.

The main reason for the leak is the bushing in the front pump, not the seal.

You would need to remove the pump, disassemble it and replace the bushing and seal. Then the torque converter will have to be replaced as well.

I would consider this since it is complete and you have never done a re build.

Roy

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Monday, March 4th, 2019 AT 2:55 PM

ROBBIEMORRIS44

MEMBER
13 POSTS

I appreciate the advice. The local transmission shop is who I went to when it started to first slip. He keep it for two days and the only thing I saw done was a biycle stop was added to end of my detent cable to increase pressure. I think that was the cause of the pump failure.

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Monday, March 4th, 2019 AT 3:43 PM

ASEMASTER6371

MECHANIC
52,796 POSTS

No, not at all. That will not cause that.

If you buy a master kit, you are looking around $300.00+.
Converter is about $450.00 to $500.00
Tools could be $200.00.

That is why I suggested a done unit.

Roy

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Monday, March 4th, 2019 AT 3:48 PM

ASEMASTER6371

MECHANIC
52,796 POSTS

I attached a picture for you of the location of the bushing and the seal.

Number 2 is the seal and number 3 is the bushing.

The torque converter needs to be replaced as well. You can get a remanufactured unit for about $125.00.

The front pump will need to be split in half by removing the bolts. It will come apart so you can get out the bushing from the front half of the pump.

Roy

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