Brake System Rebuild and Bleeding Issues
Posted: Fri Mar 12, 2021 4:01 pmI've just rebuilt the braking system on my 1966 S3 as follows (all parts from Paul Matty):-
New S/Steel pistons and seal kits front and rear
New braided hoses and crush washers
Master cylinder seals
New bleed nipples
Castrol DOT 4 brake fluid
I bled the system 4 times (using just a plastic pipe and jar) with El Supremo pumping and still had extra travel on the pedal (about 1 inch) which would then disappear with additional pumps - so I clearly still had air in the system.
I then remembered that some years ago I lost the will to live trying to get air out of my rebuilt clutch hydraulics and that a friend in the motor trade told me to wedge the clutch pedal down overnight and the air would disappear by the morning - and it did.
In desperation I tried this on my newly rebuilt braking system and hey presto a firm pedal!
It also allowed me to visually check the following morning for any possible leaks in the new system.
Just thought I'd pass this on as it may help someone else.
New S/Steel pistons and seal kits front and rear
New braided hoses and crush washers
Master cylinder seals
New bleed nipples
Castrol DOT 4 brake fluid
I bled the system 4 times (using just a plastic pipe and jar) with El Supremo pumping and still had extra travel on the pedal (about 1 inch) which would then disappear with additional pumps - so I clearly still had air in the system.
I then remembered that some years ago I lost the will to live trying to get air out of my rebuilt clutch hydraulics and that a friend in the motor trade told me to wedge the clutch pedal down overnight and the air would disappear by the morning - and it did.
In desperation I tried this on my newly rebuilt braking system and hey presto a firm pedal!
It also allowed me to visually check the following morning for any possible leaks in the new system.
Just thought I'd pass this on as it may help someone else.