Need help with a C4 trans leak

I got a C4 backing up a 302 in my shoebox. The trans was rebuilt about 3 yrs ago and when I brought it home I stuck it in a corner of the garage and left it sit. About a year ago I stuffed it into the car and got it running. I've put maybe 500 miles on the car since with no problems. I've had some minor leaks from the lines going to the trans cooler but nothing that wasnt easily fixed. Recently I've noticed small drops of trans fluid on the floor, and I thought the cooler lines were acting up again. Suddenly the puddles got a lot bigger. Today I took it out for a run after getting the driveshaft balanced and when I got home it dropped about a cup or so of fluid on the ground quick. I put it up on stands and ran it. It's got a steady leak between the trans body and the bellhousing. I tried tightening the pan gaskets but it didnt work. The leak is above the pan.I want to have it 100% for when I leave for Billetproof this weekend.Anybody have any ideas?

 

o-ring around dipstick tube??

 

What side's the leak more prominent to? Check the intermediate servo cover while your looking around..

 

You can get a dye at most autoparts stores to add to the fluid and with an ultraviolet light shine it around the area and the leak will reveal itself.

 

Front pump seal??

 

That pump seal is a ***** but it should leak more and more from the pump seal the longer it sets.
I have had the dipstick tube O ring leak and run down the pan and make it leak.

 

Rickkane, sounds like the front pump to converter seal. Sitting around is the worst thing for them, seal hardens with age, and the weight of the torque converter will deform it and cause it to leak. If it won't round back out with some steady driving, you might try a conditioner from the auto parts store that has a seal softener in it. If that is no joy, you will probably have to drop the ****** and put a seal in.

 

Torque converter seal or some of the older c4's had a separate bellhousing that bolted to ****** also.

 

I do have the seperate bell housing. Also theres no fluid inside the bell housing. It app ears to come from the joint where the bell housing meets the tran and runs down the outside of the trans. It's dead center in the middle. It will leak while it's running then after I shut it off it stops.

 

Found this out the hard way. When C4s are rebuilt they need to be installed soon after or the pump seal will get dry and shrink. You need to pull the ****** and have a new seal put in around the pump.

 

I don't use alot of the "help" products they sell nowadays, but it seems to me that they have a trans seal conditioner on the market now. I'd try it before having to rip it all apart. Good luck

 

Try the LUCAS TRANSMISSION CONDITIONER,tried it on mustang that had been sitting for awhile,worked pretty good. just remember cars are just like women ,you don"t ride them regular,they"ll make you mad and find somebody else to ride em!!

 

sounds like a seal might have rolled during installation and seeps under pressure. time to clean the area with brake cleaner get a mirror and light and sit and watch while it runs. boring as hell but .... needed!

 

I'm amazed and grateful for everybody on the HAMB who always pitch in with advice and the benefit of their experience. I can safely say that if it were not for the HAMB I probably would have ditched this addiction a long time ago. It's too hard doing it on your own.

I'm playing it safe and pulling the trans right now. It will go to the trans shop tomorrow morning and with any luck I'll get it back Wednesday. I have to go to Naples tuesday so that will give them a day to fix it. If I thrash all day Wednesday I'll be able to leave for Gainesville Thursday. I'm going up on Thursday to spend a day with my son, who is a student at UF. He particularly wants to visit a place called the Salty Dog with me. I'd like to see it because after reviewing his credit card bills it seems I am providing them with a considerable source of revenue. After that it's off to Billetproof.

Thanks again to everybody. Oh and if your in Melbourne Florida Wednesday and feel the urge to crawl under an old car stop by. I'll buy the beer, steaks,champagne,gin,cigars, ammunition etc.

 

Steaks,champagne,gin,cigars,ammunition, etc? Hell if I wasn't on the other side of the country, I'd show up just for all of the above! Best of luck, Chip Quinn

 

The gin and ammo is pretty much every day around here. Especially gin. It's like mothers milk to me. I've got some subsonic 22 ammo thats a riot to shoot. It wont even get the neighbors dogs to bark.

 

Not to hijack but on the subject of leaky C4's. Mine has been sitting for several years and doesn't leak when running but will dump quite a bit of fluid after I've moved it. Sometime days afterwords with no real apparent source. The engine vacuum source line is just a rubber tube so I replace that with a proper steel line but i am at a loss to figure where and how? Any suggestions other than what was suggested above?

 

Probably the front seal, but if you have not pulled it yet, check the vent on top of the case. Here in the South, we have dirt dabbers. They will pack mud in any hole that is not alive. If the vent is stopped up the pressure from operating will force some fluid out.

good luck,

 

I've always touted a Bombay Saphire and tonic w/2 limes as being the ultimate health drink... Tonic has quinine ya know... not a chance of malaria drinkin' that! And limes? Not a chance of scurvy if consumed in enough quan***y!!!

 

If all else fails, check the gasket between the bell housing and the case, and the gasket at the pump.

 

hi,

there is no gasket between the bell housing and main case.

there is the possibility here of parts mis-match. Early C4 cases used a rubber O-ring on the outer diameter of the pump body to the case and a gasket too.... later C4 did not use an O-ring, only a gasket.

There is a small hole in the early C4 case in the pump area that goes into the pan area. IF a later pump with No O-ring seal is installed into the early C4 case with that little hole... the fluid will run-drip out since the gasket does not seal the hole up.

I would suggest checking that stuff out when you pull the trans

 

You are obviously very learned in the ways of science. Scurvy is of particular concern to me. I am following your reccomendations as we speak, although I will be using Bulldog Gin.

 

What you say makes sense and I will check it out. I just wonder why I got about 500 troublefree miles out of it before it started acting up.

 

I know this is a late update but maybe somebody else can learn from my experience. When i got the trans from the trans shop the told me that in addition to using the wrong gasket, the rebuilder used a bushing from a C-6 instead of a C-4. I dont know where the bushing goes or what it looks like, but they tell me they are similar enough that if they're laying together on a workbench its an easy mistake to make. I didn't make it to Billetproof, but I did drive the car to the Garlits show with no problems so I guess they got it. Thanks to all for the advice.