Question1995 Chevy Astro Van AWD. My transmission overheats and smokes on warm days or when on hills. I also see droplets on the rear window. But, on cool days it does not occur. I have checked the dipstick tube, rear seal, the connector on the passenger side, and the vent tube, but cannot find where fluid is leaking from, although there is fluid on the underside of vehicle from the transmission rearward. I have to put in a quart of oil every 1 ½ to 2 weeks. Any ideas on what could be happening?
AnswerHi Wayne,
Well, here is what I think is happening. This may sound strange at first, but makes sense. I think your radiator is plugged up. The trans cooling lines go here. This cooler may be plugged. Or the radiator's ability to cool may be failing. How does the motor run? Hot? How does the radiator look? Funky and old? Corroded in green, white and rust?
The fluid is actually boiling out. You are overheating the transmission. The pressure is pushing the fluid out the rear. The seal is not bad, but he fluid is thinner and getting past the seal.
Depending on how the radiator looks, here is what I would do. First, drop the trans pan. Change the filter and gasket. Put the pan back. Replace the fluid you drained out. Disconnect the cooling lines at the transmission, both of them. Using compressed air, blow air into one of the cooling lines. This will go through the radiator cooling jacket for the transmission, and exit the other line. This will clean out this system. Reconnect the lines to the transmission. Disconnect the lines at the radiator. Install a decent aftermarket external transmission cooler. If the radiator looks bad, or the motor is running hot, I would also replace the radiator.
Hope this helps.
C J S
