1985 Chevy Mallard losing power

[eddiekep]

starts losing power after cruising at 60mph for a couple hours. It seems that the transmission is overheating and using fluid. Question: can anyone tell me if there is an oil cooling device in an automatic transmission?.

[Kiss4aFrog]

Welcome to iRV2.
There should be lines (2) coming out of the transmission and running up to the radiator. One line is pumping hot oil up to the radiator and into a cooler inside the radiator and then a line returning the fluid back to the transmission. You can also add an additional standalone cooler mounted up front where it can get more air.

I don't know for sure on a 1985 but you may have a vacuum modulator on that transmission. It uses a line from the intake manifold down to the modulator on the transmission to control shifting. Since this is a vacuum line if there is a rupture in the diaphragm inside the modulator it can suck trans fluid up into the intake and then into the engine and burn it.

[eddiekep]

many-many thanks for detailed reply from kiss4afrog member. I will inform the mechanic when I take it for repair, then let u know if he fixes problem.