Hello & Transmission leaking fluid question

[scmsltn]

Hello, how are you guys? I just bought a 69 bronco on ebay and it arrived a few weeks ago. It is a really good start, low mileage, little rust, 77k original miles and still has a good running, numbers matching motor. The PO did a lot of upgrades I would have done, power steering, front discs, and a c4 tranny conversion. I will add some pics when I can. I love this site and all the information it has.

Anyway, the issue I am having is that after I drive my bronco and park it, there is a big puddle of fluid the next day. Everything is really dirty so, in trying to see where it is leaking from, I wiped all the wet fluid from the underside and drove it again. I sat under it for about 5-10 minutes when I got home with a shop light waiting for the leak...It never came. Then the next day, a big puddle (and it wasn't driven again, it just sat). So it leaked when I was not watching it and the puddle is a few feet in wide, not a few drips.

I do not think it is a heat/temperature issue as the c4 tranny conversion was done fairly recently and it has an added tranny cooler. The tranny shifts great when driving (it sort of clunks into gear from park intially) so nothing has been burned up. The fluid levels look OK, but I am going to double check. It is parked on flat level ground in the garage.

It just seems odd that it didn't leak while I was watching it and the fluid was at it's hottest. If I can get home before it is light out I will try to see more...I haven't had time to get underneath it after it did this. I figured I would check here for any tips if this has happened to someone else.

Thanks! Jeff

 

[scmsltn]

Also, if there are any bronco owners in the Reno, NV area who meet up, let me know... I would get involved.

 

[Dannyboy71]

Congrats on the new bronco and welcome to the site. This is definitely the place to look for answers and help. I would think the best thing to do is clean the area real well with some kind of cleaner/degreaser, then take it for a spin and try to locate where the leak is originating from and go from there.

 

[CopperRanger]

Hi Jeff, and welcome to the site. My 74 with a C4 does the same thing, but not that extreme. I have noticed that when it's hot it doesn't drip, it's after it cools down is when it starts to leak a little. I think mine is from either the pan gasket or the vacuum modulater. Hopefully a few more will give some advice.

 

[scmsltn]

Thanks for the welcome guys! This weekend I am going to have a detailing place put it on the lift and steam clean it and pressure wash it. It will take off the 45 years of crap and then I will be able too see better. I will try to catch it in the process of leaking while it is cooling down. I'll keep you guys posted if I find anything.

 

[70_Steve]

It just seems odd that it didn't leak while I was watching it ...

Hi Jeff, Congrats on the new-to-you Bronco and welcome to CB.com.

Yeah, I don't like to take a leak when people are watching either, but that's just me...

Have you determined that it is tranny fluid? Is it red?

Sometimes the leaked fluid will blow back onto some part of the drivetrain as you drive it, wetting things pretty good. Then when you stop, it takes a couple minutes for it to run back down and start dripping.

Put a piece of cardboard underneath and wait for it to drip. Then it should be easy to tell exactly where it's dripping from, understanding that where it's dripping from may not be where it's leaking from..

 

[scmsltn]

Yeah, I don't like to take a leak when people are watching either, but that's just me...

^^^Classic!

Yes, it is red fluid and definitely tranny fluid. After it is pressure washed I will just lay under it with a few beers and wait. I am wondering if the PO topped off all the fluids before he shipped it to me and this is a case of it being overfilled. Maybe if it has puked enough I won't be able to replicate it. We will see.

 

[DirtDonk]

Was thinking the same thing. An automatic can pump fluid into a lot of little spaces and when you stop it eventually works it's way back down into the pan and environs.
If you're lucky, it's building up and leaking out of either the filler tube fitting or the modulator in the back.

Unfortunately though, both of those are easy to see and would likely be quickly diagnosed if they were the sources of the leak(s). But at least they're worth keeping an eye on once it's clean. Like was said, once the oil has built up underneath, it can literally come from anywhere and be feet away from the actual source.

Next time you're looking under there, take a peek at the transmission's dipstick tube. Is it in the pan ("pan fill") or side of the main case ("case fill")? And either way, is the screw fitting tight?

If it's coming from the modulator sticking out of the back of the area by the pan, maybe it's an old o-ring leaking, or it might even be the clamp is loose or missing?

Good luck.
Oh, and if you ever get over the hill on the CA side of things, take an extra side trip down to Stockton and stop in the Wild Horses shop. Give 'ya the nickel tour sometime.

Paul