White smoke after replacing brake pistons?

oliverr87 · Oct 13th, 2005, 09:28 PM

Hi, I have a 1987 Nissan Pickup truck with the Z24 engine 4 cylinder, fuel injected.

My uncle came home with it, and he was going to replace the brake pistons because the brake master cylinder (not the brake booster) was leaking, and the pistons were worn. So he replaced them, but now when the car starts up, white smoke pours out of the exhaust. Any ideas? I only see one hose going from the booster to the engine...did brake fluid get in there somehow? It doesn't smell like oil...in fact it doesn't have much odor at all. Just pure white smoke...the head isn't leaking any oil, no coolant leaking, and the car was working fine before replacing those pistons. Anybody have ideas?

brookwood61 · Oct 14th, 2005, 07:03 PM

How long did you run the truck? Did it quit after warming up? If so, it might have been condensation built up in the exhaust. Mine does this after sitting a day or so. It is normal.
A small amount of brake fliud would burn off rather quickly, if it did get into the vacuum line. Take the line off the booster and plug it. If the smoke quits, change the booster, and check the rear of the master cylinder, it should be dry. If it's wet, change it too.

For fluid to get into the booster, you would have a very noticible vacuum leak. The engine would idle rough, and the brakes would have a hard petal.

If it continues smoking, keep an eye on the temp guage. You may have an internal crack, or a bad head gasket.
Good Luck

MrOldLude · Oct 15th, 2005, 10:00 AM

White smoke is usually a tell-tale sign of coolant burnoff. Though, relating that to a brake job seems a stretch.

1997XETruck · Oct 15th, 2005, 11:11 AM

Try unplugging the brake booster line just to eliminate that possibility (obviously not while you're driving

) but I don't really see how the two could be related...

Heath