Michael. 2313 Report post Posted October 5, 2015 When it comes to pistons inside two different units, generally what, if any lubricant should be used on the internal seals for the following: Brake system pistons - Vaseline, red rubber grease or just brake fluid? Automatic transmission valve body pistons - Vaseline, red rubber grease or just ATF? Quote Share this post Link to post Share on other sites
gjm 3258 Report post Posted October 5, 2015 A - red rubber grease. Definitely. Amazing stuff B - ATF. Anything else that gets into the valves could cause a blockage, although this is what I have always done. I'll happily acknowledge if this is proven incorrect. Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted October 5, 2015 A - red rubber grease. Definitely. Amazing stuff B - ATF. Anything else that gets into the valves could cause a blockage, although this is what I have always done. I'll happily acknowledge if this is proven incorrect. You nailed it Quote Share this post Link to post Share on other sites
Michael. 2313 Report post Posted October 5, 2015 Thanks for your thoughts Graham. I've always found conflicting info. Even a trans re builder guy in New York I got some stuff from suggested Vaseline for the automatic valve body accumulator pistons, these are about 1" - 1.5" diameter types with seals at each end of a piston that moves around while acting on a heavy duty spring, regulating shift shock and all that stuff. But then other say Vaseline is bad for seals, but are transmissions a different grade of rubber that is resistant to such fluids / petroleum - perhaps that is the case. Quote Share this post Link to post Share on other sites
polley 916 Report post Posted October 5, 2015 Would be using ATF, that's what it is going to live the rest of its life in. 1 Quote Share this post Link to post Share on other sites
