78 F 150 with a c6 tranny leaking bad from front seals . After talking to mechanics they all seem worried about the pump being bad. how can i check this. i posted in tranny forum but no one answered

 

Other than the seals leaking what is the tranny doing to make the mechanics think your pump is bad. A seal leak doesn't mean the pump is going out.

T. Roberts
UFD Local 1147

 

Mechanics seldom fix anything any more - they either rebuild or replace things. I expect this is to avoid come-backs as consumers do not understand the risks involved.

I am no expert on transmissions - I intend to rebuild mine after Xmas, so I have been gathering information on it. The possible problems you face is that the torque converter output shaft is scored or damaged where the bad seal is - if so, you will either have to have that machined, or replace the converter. (Not too expensive)

As to their worry about the front oil pump, if there is not enough fluid pressure the trans will not shift correctly. It looks to be a simple device. You can dismantle it and look for damage and scoring when you have the trans out. This could have happened if it has been ran low on fluid.

Also, my book list some pressure checks you can make, but I do not fully understand what is needed. Maybe some expert will check in and tell us how to make those tests.

If you do a Google search on the C6 there is a lot of information available, and there are rebuild manuals you can buy. I have one published by ATSG (Automatic Transmission Service Group) out of Miami which I do not recommend. It is geared for the experienced professional and not real helpful for the shade tree mechanic.

If it was me, I would just jump in and change the seal and see what happens. Worse case is that you will have to pull the trans twice, but the second time is easier than the first.

 

ty all i guess it is drop it and see what falls out. I have another guy who will give me a rebuilt one for 100 and a trade in if it looks nasty after it is on the bench i may do that instead

 

mario56, it's common for a C-6 to have the pump body seal leak. With the large diameter, aluminum and iron, different expansion rates and hard cooked seal. Be sure to replace the torque converter seal ( converter snout). Be sure to stand the trans on end with the tail shaft facing down but not on the output shaft. I have found that new pump gears are not as thick as the original gears and there can be a difference in thickness between the driven and drive gear, quality control thing. The finish on replacement gears isn't as nice as the original gears. My old gears had tighter clearances than the new. Polished and reinstalled. Carl....o&o>.......