MISSING ATF????

[pontiacsteve22]

Hi folks I have a trans problem, my atf just gets low after a short drive over a few days...I checked underneath and no leaks on the driveway, also no signs of leakage underneath????? I was told it might leak into the radiator, its the original one from 1990..T coolant looks good, they said it should be kinda pink like strawberry milk. Its been 2 years since it was rebuilt by the same people that did the rebuild before....I was wondering if anyone has had this problem...Thanks in advance...

[96 SSEi]

hi, if there is no sign of leak below, I would check the fitting connecting to the rad - it could leak from the fittings and collect at the bottom of rad bracket without hitting the ground - had this in one of my 90's W bodies

[RJolly87]

A leak that bad may be hard to spot, because it could be washed out, however that would be fairly obvious because of the fluid on the ground.

It could be getting in to your coolant (which should be green), but the oil would be at the top.
There is a remote chance it could get in to the oil, so keep tabs on your oil level to make sure it's not doing something weird.
It also could be ingested by the engine, thanks to a leaking transmission modulator.
How much fluid are you having to add, and how often?

[pontiacsteve22]

Thanks Guys for the help, as it turned out the vacuum modulator on the trans was bad.... that thing was bad, eating atf like 8 ounces per 10 miles..And it had a white smoke from the tail pipe...This is mainly the problem from what a mechanic told me, if no leak under, or the coolant is green not like pink.Then you gotta check here, when I removed mine atf was flowing out... Well I learned something new...also the old modulators where very large, the new ones aftermarket since GM stopped making them are a 1/3 of the size..So don't freak out when you go to buy a new one..Mine came from Advance Auto....take care guys, this site is very good...

[RJolly87]

It also looks like the unit from Advance Auto is adjustable. If you find yourself in want of firmer shifts, you can adjust it accordingly. The adjuster is usually in the vacuum nipple, and shouldn't be adjusted more than a half turn at a time.

I have about 3/4 turn in to mine, and the shifts range from firm on a good day, to slightly annoying on a bad day.

[RJolly87]

Also, depending on how long it was burning that amount of ATF, also keep tabs on your catalytic converter and o2 sensor, as they can easily become plugged up with that much oil being burned.