Been fighting a front disc brake issue for a bit. When leaving the garage for a drive the power front disc brakes work great, but as I continue to drive and the engine bay gets HOT the front brakes drag to the point where I can't rotate the front wheels by hand when I jack the front end up. Both front disc brakes bind equally with no pulling of the car to the left or right. The brake pedal always returns to its (brakes off) normal position. Last week I retracted the push rod from the booster to the Master Cylinder to shorten the throw in to the MC and that seemed to work for a while, but yesterday the issue returned. It only happens when the engine bay is hot, both calipers drag equally, there is good vaccum to the booster from the engine and fluid levels are good and brake bleeding has been done multiple times. I'm about ready to purchase a new Master Cylinder and see what happens, but I feel as if I am guessing.

Any brake experts out there that have had a similar issue. Engine is an FE390 so the engine bay gets very warm/hot, which seems to be a causal factor in the brake binding issue.

TIA for any thoughts and or suggestions!!!
Brian

 

Someone on a Facebook forum had similar issue. I've tried to find the post to see if they resolved their issue, but I can't locate it. I have seen where using DOT 4 or 5 brake fluid will cause that condition, even if that fluid is flushed out and replaced with DOT 3