johntomferg
Active LVC Member
Anyone else had this problem? Mechanic said it is likely a bearing in the pump that is causing it to slowly leak. Just curious.
Transmission Pump Leak
- Thread starter johntomferg
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ToddG
Dedicated LVC Member
What's a transmission pump? Any relation to muffler bearings?
no relation to muffler bearings. I assume he's referring to the "front pump"...it's the pump inside the transmission that pumps the transmission fluid. I don't know anything about trasmission internals but I don't see how it could leak and if it did where would the fluid leak to?
johntomferg
Active LVC Member
Yes, the pump on the front side of the transmission. The answer to where it leaks to is "all over the damn floor; one drop at a time."
johntomferg said:
HAHAHA... nice answer!
I've never heard of that! Of course I'm not that familiar with the LS tranny... I've delt mostly with AOD, AODE, 4R70W, EOD, and the speradic GM tranny; all of which have the pumps internal. If my tranny goes, I'd be VERY tempted to attempt a manual swap... maybe a T-5 or T-56. Might be too much of a pain though.
Good luck brother!
johntomferg
Active LVC Member
The tranny itself was not damaged and shifted smooth and fine. I just had a small leak. They determine that it wasn't the gasket for the pump and the guy at the transmission shop here in town indicated they had seen something similar and thought it was the actual pump that was causing the leak. Anyway, they are supposed to get it to the transmission shop tomorrow and I should know more then.
johntomferg
Active LVC Member
Okay Beaups, here is the explaination I got on the last phone call (paraphrased from the AAMCO guy).
Basically, when you first look at it you would typically replace the front pump seal. They had tried that but then it started leaking again. What is turns out (and this is where I misunderstood previously because the word bearing was introduced, I assumed it was a bearing inside the actual pump) ...there is a an item called a bearing/thrust washer that is behind the pump and then another seal behind that. If there is a problem with that bearing/thrust washer or the seal behind it, then you can change the outer most seal as many times as you want and the leak will come back. The shop here that I normally take it too doesn't touch anything past the front seal without sending it out to the AAMCO establishment who has the expertise and tools. He indicate this would be a minor repair and once the guy has it he can tell more about it.
Forgive me if the terms I use are not correct or my paraphrase is not the best, but when it comes to things I have not seen in a somewhat closed system like this all I can do is paraphrase. Additionally, my background is primarily in Computer Engineering. So while I have an general engineering background and can understand how the system operates to generate the results, I do not know every component of this particular system at the detail many of you do. In my case, I have to take a certain leap of faith on people that have always done good work for me in the past without over charging me. He indicated that we were not talking about hundreds of dollars in the price for this, that it was not the primary internals of the transmission that were being touched.
Best I can do on the explaination at this time: I hope it is more clear.
Basically, when you first look at it you would typically replace the front pump seal. They had tried that but then it started leaking again. What is turns out (and this is where I misunderstood previously because the word bearing was introduced, I assumed it was a bearing inside the actual pump) ...there is a an item called a bearing/thrust washer that is behind the pump and then another seal behind that. If there is a problem with that bearing/thrust washer or the seal behind it, then you can change the outer most seal as many times as you want and the leak will come back. The shop here that I normally take it too doesn't touch anything past the front seal without sending it out to the AAMCO establishment who has the expertise and tools. He indicate this would be a minor repair and once the guy has it he can tell more about it.
Forgive me if the terms I use are not correct or my paraphrase is not the best, but when it comes to things I have not seen in a somewhat closed system like this all I can do is paraphrase. Additionally, my background is primarily in Computer Engineering. So while I have an general engineering background and can understand how the system operates to generate the results, I do not know every component of this particular system at the detail many of you do. In my case, I have to take a certain leap of faith on people that have always done good work for me in the past without over charging me. He indicated that we were not talking about hundreds of dollars in the price for this, that it was not the primary internals of the transmission that were being touched.
Best I can do on the explaination at this time: I hope it is more clear.Okay... so the pump is located inside the case. It doesn't sound like a horrible problem, but given it would seem to require removal of the transmission... and some limited break down of it... gonna be pricy
2001LS8Sport
Dedicated LVC Member
NateRW21 said:
Those transmissions ALL have the pumps as the last item bolted on to the case on the front of the trans. I don't know what you mean by "internal", but the pump cases are definitely EXTERNAL. Where most pump leaks come from are either the O ring around the outside of the pump that seals to the case, or the converter seal in the center of the pump. If the converter bushing in the pump, or the input shaft (hub) on the converter itself, get wear and clearance, then there can be a leak past that seal. The converter hub actually inserts into the pump gear. If you're leaking there, you will more than likely need a new bushing, seal, and converter. If it's the O ring, you can have the O ring replaced. Either procedure requires the removal of the transmission assy.