C4 Tranny leak from hell...

Since this group is world-renowned for its expertise in all things Maverick and Comet, I figured I would throw in MY towel and ask a question thats been keeping my Pegasus down for the last year.

Parked (under cover) in the back yard, running, yet unable to move under her own power (without 5 quarts of tranny fluid), she is a sad sight indeed. My homeowners restrictions prohibit lengthy "in the driveway" repairs, so I have to move her back and forth between the tarp-covered garage in the back yard to my driveway when I get the itch to work on her.

Details: Coast High Performance 302 (less than 5 miles on it), Weiand intake, BDS 6-71 blower, twin holley 80457S carbs, heddman headers, C-4 tranny with Gear Vendors over/under drive, MSD 6A ignition/wires/distributor, etc.

What is killing me is that &^*$#$ C4 tranny! I can fill it with fluid, run around, put it up on the ramps, look closely and not a single drop of fluid leaks. If I place a plastic tub under it overnight and come out in the morning, the entire plastic tub is filled with tranny fluid. Needless to say, the tranny doesn't move anything until it has been refilled, only to repeat this whole episode the next time it sits. I *think* it might be the O-ring around the dipstick, but it can't be that because the tranny is EMPTY in the morning.

I've gotten so fed up with it that I've yanked the blower, GV O/U drive and put it back into a somewhat stock config just out of anger. It runs like a bat out of hell, but don't count on it moving 1-foot the next day since it has no tranny fluid. I've checked all around the gasket surfaces and there is nothing there. I know taking all that stuff OFF has nothing to do with the tranny, but I can't see parking it in a humid Houston back yard left to rot and sit because it can't move itself out of its own tire-prints:confused:.

I like to consider myself an educated Maverick tech, and frequently offer advice when I can, but for this I'll have to defer to the true Maverick Gods to work it out. Lord knows I can't and its putting a real damper on my restoration efforts simply because every move of the car will require a plastic catch-bucket and 5 quarts of tranny fluid.

I welcome any and all suggestions/comments/flames.

Pegasus

 

Tracy; check the modulator valve. If the diaphram is ruptured, it will suck trans fluid into the intake and burn it as white smoke out the pipes. Fill it up to the mark on the dipstick and start her up, check the valve for leaks by removing the vacuum line. You should see trans fluid if it is leaking. Hope this helps some.

 

Tracy; last time I suggested the mod valve. Can you see the fluid? Put the car on stands, run it through the gears and watch for the leak. To leak that much, it would be a front pump or tailshaft seal (maybe). Give it a try.

 

Tracy, great to see your posts on the board again!!! Been wondering how things have been, I am glad to hear the book is doing well! Sorry no help on the tranny, I just wanted to say hello.

Don't be stranger!

 

Tracy, it's definately the gear vendors unit.
I recommend sending it to me immediately for further analysis.

 

Take a look at the cooler line at the side hand side of the tranny near the top. It may be rotted through or possibly the pan gasket is bad.

 

If it is leaking that much over night it has to be a leak low in the tranny. That would leave out the pump, fill tube and probably even tranny lines. You didnt mention if it was leaking when it was running unless I missed it. I would guess a pan gasket, hole in the pan or possibly a crack in the case itself. Get it to a car wash, clean it up, fill it up and watch for the leak. Until you find out where it is coming from its kinda hard to fix. Good luck..

 

Pegasus,
From your story (as I understand it) the tranny isn't leaking while it is running only when it sits overnight. I am going to assume that not all the fluid leaks out it just doesn't show on the stick and you have a 5 or 8 quart pan full of oil - is this correct?
Assuming that what I have described is true, then you have a good chance of locating the leak.
Fill the tranny and run it at an idle for about 20 minutes. Shut it off and place a CLEAN piece of cardboard under the tranny and place tape on the car where the edges of the cardboard are (both sides front and back). wait two hours and check the card board for spots (less time if you like) when the first spots appear jack up the car if it isn't already on blocks so you can get under and watch. measure from the four points of tape to where the drip hit the cardboard and then use that to pinpoint where the oil dropped from the tranny. Start there and follow the leak back to where it disappears. If it is wet in one spot and dry in the next then your leak is at the last wet spot.
I believe you will find it at the extension housing gasket or leaking from the vent tube. There is an off chance that it is leaking from the intake side of the pump this will be evident as leaking from the bellhousing drip hole in the bottom of the bellhousing. When you find the leak just reseal that area and try it again.

PaulS

If money is no object then you can buy a dye that goes in the oil and rent a leak detector "Black light" that will make the dye in the oil glow in a brilliant yellow or orange and the leak will be easy to watch as it moves from one spot to the next.

 

Though this sounds worse than any I have seen, I would think there is a good chance that the converter is draining back at night over filling the pan and could simply be over flowing out the vent, though I have not seen one do it that quick that is what it sounds like it is doing...usually meaning the bushings in the stator where the imput shaft runs is wore enuff the fluid will leak past when it sets....if so a simple solution could be placing a one way valve in the cooler line.

 

I would try the dipstick O ring first - like you said. It will cost about $.15 for a new one from the hardware store and about 10 minutes to pull the tube and put it on. Did you drop the engine and tranny in as a single unit? Thefact you said it was a new motor makes me think.

I had one leak about a quart on the floor over about a week. I had just shoehorned a 460 into a 1952 F1. I pulled the tube and found that the tube was bent and wasn't lining up real straight with the hole. I guess I bent it when I was thrashing with the headers trying to get everything dropped in.

I straightened the tube and got it to line up real well with the hole -- so it would slip right in and bolt to the block without a O-ring. After I thought everything would line up real good I put on a new O ring and slid it in. Never had any more problems. Hope your fix is just as simple. Good luck.

Cleaver

 

Robert,
In the valve body there is a convertor check valve that should prevent the convertor from draining into the case. It may have been left out when it was built. if you put check valevs in the cooler lines it will affect the lube pressure which is not real high to begin with. The good fix would be to replace or install the internal check valve.

PaulS

 

Paul I realize there is the valve in the v-body I was only offering a simple solution that anyone could do, though not the best fix it would correct the problem in a way anyone could do. I was just offering a suggestion. and as for what I had said if the bushings in the stator were wore severe the fluid will leak back.

 

The most common problem for the symptom your describing is the dipstick O-ring

When the tranmission sits overnight , the converter can drainback into the pan well above the dipstick tube case hole , leak past the o-ring , and run off the pan rail making it look like a pan leak

 

Tracy-
Man, I thought that you fell of the face of the earth!

How have you been doing?

Seth

 

Hi all! Thanks for the replies!

I know I have been remiss from the board for awhile, but for my friends here, they know why. Its hard to come back from nothing to getting back into our favorite hobby (Mavericks/Comets!)


Threw the b*tch (never referred to Pegasus as THAT before) up on the ramps, filled her tranny with 5 quarts of high-grade, waited for close to 45 minutes under the car, was about ready to give up when she started leaking from the left rear bolt of the tranny pan. There was hardly 1/4" of link area, straight from the pan down to the ground.

Now for the embarrassing part.

I personally supervised the C-4 rebuild, and thought it 100%. Apparently I didn't look close enough. Not only was the left-rear pan bolt very loose, but also the 4 others surrounding it.

I feel like an idiot, posting on the board for such a stupid problem. In my defense, I trusted the tranny shop to make sure the tranny bolts were to spec. I should have known better.

Stefan: If able, remove this post to pretend this emarassement didn't happen.

Yes, All who helped, it was a loose tranny pan bolt. My apologies for getting frustrated with what I thought was a complex problem for what turned out to be nothing at all.

For Pegasus; I take back all those bad things I said about you. Prepare for the full-body powder-coat!

Thanks again everyone,
Tracy
a.k.a. Pegasus