Why does the clutch hydraulic line build up pressure when hot on my 1991 chevy truck?
Just replaced the M/C and now when the truck gets to operating temp the pedal is high and hard.
Barely tap the pedal and it slips..
get under truck and bleed off presure and all is well till the next morning.

 

did u bleed the master right? and repeatedly i also tap them lightly to knock any air loose

 

Thanks for your response. I bled it correctly with no air in the line.
If I had air the pedal would not get hard. The line builds pressure as it gets hot.
I even insulated the line but it changed nothing. Soon as it cools off (like overnight) all is well till it gets back up to operating temp.

 

Did you fill it with an un-opened fresh can of fluid?
And not leave the system open overnight before closing it?

i.e. moisture absorbtion.