Bigsk8r

My son was driving my 1970 98 and had an incident where Transmission fluid came out of the dipstick and into the engine compartment. It was pretty disturbing but does not appear to have damaged anything.

Could this have been caused by the stick not being in all the way when last checked? Or is the pressure required to push it up the tube a sign of big trouble?

Thanks...

oldcutlass

Was it overfilled? The level is checked with the engine running after it's warmed up.

Olds64

ATF won't belch out the dipstick tube unless something is wrong. Did your son add ATF to the transmission? Remember, ATF should be checked with the car idling, in PARK and HOT.

Eric is quicker on the draw. Great minds think alike.

66_Jetstar

The vent is probably plugged. Mud wasps have a way of filling those.

Bigsk8r

Thank you. I am thinking that it got topped off while cold and on the first combination of warm day and long drive, this happened. Will finish cleaning up and make sure to fill to lowest point on the stick initially then check the level when Hot to keep this from happening again.

oldcutlass

To be honest, the difference between cold and hot is not going to cause this.

Bigsk8r

We'll see. The car was parked in a garage at my son's place and the fluid was topped off sometime in early January when it was cold and he was not running the engine at the time. It could be that having it at the very top while cold resulted in way too much when hot. Either way, I am going to get a 5 gallon bottle and watch it very closely...

Thanks.

oldcutlass

Filling with the engine off is probably the cause.

Vintage Chief

^x2^ Most likely was overfilled even then. Although, generally I don't see it puke out the filler tube, it generally pukes out the vent hole.

66_Jetstar

The trans fluid reads high with the engine off, not low...

Olds64

Just so you and your son don't feel bad, I had ATF belch out the dipstick tube of the C6 in my 86 Ford truck. I added the fluid too fast, even though the engine was HOT after changing the transmission filter.

If you get a 5 gallon jug of ATF fill a quart bottle and add it to the transmission 1 pint at a time. That way you can monitor how much you add.

Bigsk8r

Well, it might have been something else...

When I checked this morning after letting her run for a while, the level was just under the Low indicator on the stick and the car will not shift to Drive or Reverse. You can hear the linkage engage, but nothing happens. After 53 years, it has finally demanded the rebuild we have known was coming. Will start a different thread about that...

oldcutlass

Try topping it off

jaunty75

As most everyone has said, it was overfilled. This exact same thing happened to my mother way back in 1973 when she was driving our '73 Custom Cruiser. White smoke coming out of the back of the car. Scary looking. Took it to the dealer. They checked the fluid level, and it was overfilled. Fluid was coming out of the top of the tube and spilling onto the exhaust. They took out (through the tube, I think), enough fluid to get to the full mark with the transmission at operating temperature, and the problem never recurred.

Bigsk8r

So... interestingly enough, we are on the road again. Where the car was parked over the winter had an unusually high amount of ATF on the pad under the car, implying that a lot more leaked out than we previously thought. Also, son checked the fluid cold and saw some on the stick, so did not add any despite me thinking he had.

After I followed Eric's advice and topped it off, everything returned to the previous normal. What perplexes me is how is that it was so low that I had to add nearly 3 quarts, but that it still had the blowout thru the dipstick?

Maybe we'll never know, but you can bet I'll be checking it every few times I take her out...

oldcutlass

Glad you're back in the saddle. Look to see where the leaks are and see if you can easily address them.

Vintage Chief

Difficult to determine exact sequence of events leading to a most likely overfilled condition; yet...

(1) Always read transmission dip stick w/ "engine running" at normal operating temperature - key is "engine running".

Regarding loss of transmission fluid (besides that which puked out the filler tube):

(2) Check the vent hole/tube on the transmission casing as others have suggested. This is an important design feature...clean it. The vent allows heat to escape the transmission as well as provide ability to draw in cooler ambient air. If the vent is clogged, there is no place for heat to escape...other than the transmission filler tube. As the heat builds, the pressure builds.

(3) While you're down there checking the location of your vent hole/tube & cleaning the vent hole, visually check the automatic transmission modulator valve looking for any visible signs of leakage.

Vintage Chief

Olds64

Good to hear she's back on the road. 👍