I bought a 76 F150 8 months ago from a lady that had it in her garage for 25 years. When I got it home I changed out all the fluids, including the transmission fluid and filter. Shortly thereafter I noticed it was leaking fluid from behind the trans dust cover so naturally I thought I didn't get the torque converter drain plug tight. After checking it and finding it to not the the source of the leak I took it to a local guy to check over.

He replaced the front seal on the trans input shaft and that was that. I brought it home, parked it in my driveway, and then it sat for a couple days days. When I went to get in it after those couple days I noticed there was a puddle of transmission fluid under it and it appeared to be leaking from the same place.

I took it back to him thinking he put in the wrong seal or something else started leaking. He put it up on his lift with it running and it wasn't leaking. I told him to take it for a 10 minute drive and then come back and turn it off and it would leak. Well it didn't leak. He thinks the source of the problem could be that I park it on an incline in my driveway. Now I have always set the parking brake while in neutral, let it coast back, and then shifted it to park so it's not resting on the transmission while parked.

My normal commute is 4 miles from my house to a flat parking lot. When I come back to it at the end of the day there is a pool of transmission fluid under it there as well. So if his theory is correct, why would it then also be leaking while parked in a flat parking lot?

I'm going to try backing it up my driveway to see if that stops the leak but it just seems odd to me that parking on an incline would cause it to leak. I've stained up my street (also on an incline) and my driveway, so I've started putting an oil drain pan under it when I park, but seeing as though I live in the NW and we are entering the rainy season, it will end up filling up with water. Frankly I'm getting tired of dealing with this as it's my daily driver, so I have to crawl under it twice every day in my dress clothes.

 

"Parking on an incline" that's a good one .. If the trans is sealed properly you can hang the truck from a tree and the trans shouldn't leak .. I have heard this more then once "Most of the time it's not just the seal" .. There are several threads on this forum on C-6 front seal leaks that will help .. Made me think of this

 

If the font seal was installed properly and not damaged in the process and the torque converter isn't worn where the seal rides, then my guess would be the front pump seal (p/n C6AZ-7A248-A, 9½" ID X 10 5/16" OD X 1/8" TH) is leaking. This is a common C6 problem.

 

I think it's the front pump seal too,happened on a couple of mine. Odd the mechanic never just went ahead and replaced it at the same time, since it's not an easy one to get to. I had a front pump seal leak and follow along the top of the pan edge before dropping.Made me think i was not getting the pan gasket right until the third time , them we pulled the transmission and found it.

 

I always replaced the seal too. I class this as one of those " well, while I'm here, I might as well..." jobs. You're right, it's not easy to replace, unless the trans is already out, then it's just a handful of bolts and pop the pump out. Easy enough.

 

I got the truck back Sunday and promptly put it in my garage with a drip pan under it. I came out to drive it to work Monday and guess what, there's a puddle of transmission fluid on the drip pan. I knew it was going to dip but I thought I would give the guy some credit and at least check it. So now I'm looking at the cost of labor to pull the transmission a 2nd time which I'm not too happy about. I ALWAYS do those "well I'm already here so I might as well..." kind of things because invariably stuff like this happens. Maybe it's not the pump seal, maybe it's a bad front seal, who knows. All I know is I took it to a guy to get it fixed, paid the bill, it's not fixed and I don't have the money to pay to have someone else look at it.

 

The C-6 trans is one of the most used auto trans by ford .. The issues as far as front leaks are concerned are well documented and the repairs as well .. The person who did the repairs should have known that .. They should be taking it back out and fixing it on their dime except for maybe the parts they didn't change .. Can you even tell if the transmission was removed ? ..

 

I haven't crawled under it yet but I need to if it ever stops raining here.