E28 clutch hydraulic failure

[bmwfreund]

Here in Arizona at temperatures over 100 degrees in stop and go traffic the clutch
hydraulic system often failes. I replaced the master and slave clutch cylinder and fluid (DOT 4) last year for this reason. The problem (clutch pedal stays on the floor) occured again this week. The system works again after the car cools off. Camelback BMW could not duplicate or find the problem. I need help. This 535is is to heavy to push.

 

[Big Daddy]

Sounds almost like the fluid has boiled, like when your brake fluid boils. Have you tried draining the system and replacing it with ATE Super Blue synthetic brake fluid, it has a higher boiling point.

 

[bmwfreund]

Thanks Big Daddy, I am ordering that ATE Super Blue Brake Fluid now.