My C4 will not stay in first or rev when cold, but its fine when warm, or if I over fill it.

History on the tranny: C4 from a 79 Pinto 2.3. Not that it matters, but it was low miles. The donor car had carb issues that kept it off the road. The car ran but the car did not move unless the RPMs were high, and I soon discovered that the fluid level was very low. Once I fixed the carb and added fluid, it drove very well.

The car its in: 78 Pinto 2.3 Turbo EFI. Nothing high power, just a stock set up, 8PSI, no I/C. This car came with a C3 that was working OK with the 2.3T but was very leaky.

After I did the swap, including new pump seal, fluid and filter, I ran the car with tires off the ground and it was popping in and out of gear. I checked the fluid level a few times until it was dead on full, but not knowing if the dipstick was correct for the car I added fluid little by little until it would stay in gear (about 1 quart more). From that point it seemed fine, cold and hot, for a while until it started leaking out where the dipstick tube meets the case.

The top of the dipstick tube for the C4 2.3 is where the stock turbo is, so I needed to bend it a bit, and knowing that it would have a side load on the case it might not seal well so I used a little RTV to help seal it when I installed it. It sealed well for a while but now it leaks there and I assume that the level is now where the leak is.

My question is what would cause the tranny to do this?

I have a few other C4s around, but I would rather fix this one or do my first rebuild.

I did a bunch of searching and I found more issues with hot shifting problems.

Thanks for a great site, and thanks in advance for your time.

It sounds like low fluid.
When warm the fluid will expand.

Check the breather for grease, mud or bugs.

If the breather is plugged it will indicate a higer fluid level.

The full running mark is even with or close to the pan/case junction.

Thank you.

I will check the breather: Is that the little cap thing on the back of the main body, and what is the best way to do this?

The best I can tell is that when it's fully warm and reads full that the level is about at the top of the dipstick hole in the case, and when the car is off the fluid settles back to the pan and the level is up into the tube above the O-ring. Is this normal?

If this is the normal fluid level then I need to seal the tube better, otherwize it seems that if I want it to work fine cold I need to deal with the car leaving its mark when parked. As mentioned the tube no longer goes in fully straight, but not too bad. The factoy tube has one O-ring and I have replaced it with a new one, but even that did not help much. I purchased a flex tube and dipstick from Lo-Car that has two O-rings and I plan to try that if I need to. This will allow the end to be centered and hopfully allow the rings to seal better. I would rather use the stock tube to keep the car stock looking.

Is there any type of sealer I could use as well that would help seal the tube?

If it were up to me I would swap in a T-5 (like my other turbo Pinto), but this one is my wife's car and she wants it to stay an automatic.

Thanks again,
Bill