Brake system issue...

[EM-0785]

If it is still an air bubble issue, this may help? When bleeding my slave I had issues. After research, I decided to reverse bleed, air bubbles rising made sense. I also liked the syringe technique found on motorcycle blogs, worked very well for me. First time, lots of air release, firm pedal, done. Then when I upgraded to Wilwoods recently, I used the same technique on both front and back, just as effectively.

Given my three masters in the footbox, and the fact I wasn't having luck with push and pull pressure methods, the syringe reverse bleed became my one person method, it's so simple and effective on mine. A 10 cc syringe is easy to reach in with one hand to the masters and lift the plunger with thumb to remove fluid. Then used a 30 cc syringe to add fluid from the bleeder using short tubing from Lowe's and adapters from my pressure/vac kit. Very controllable and good in tighter spaces. Brent

[jhv48]

Perhaps a dumb question, but one that needs answering. Did you accidentally use a silicone brake fluid and mix it with a non synthetic brake fluid? They don't play well together and will wreak havoc on lines and seals.
Just a thought.

[Akimbeau]

Originally Posted by jhv48

Perhaps a dumb question, but one that needs answering. Did you accidentally use a silicone brake fluid and mix it with a non synthetic brake fluid? They don't play well together and will wreak havoc on lines and seals.
Just a thought.

All the same synthetic brake fluid

[jhv48]

Originally Posted by Akimbeau

All the same synthetic brake fluid

Next question. Did you buy the car from someone or are you the first owner? When you got the car, did the brakes work correctly? What type of brake fluid did it have in it? Most come with DOT 3 or 4, though some have 5.1. If the car was setup for racing, it might have used DOT 5 fluid, a silicone based fluid that works better in higher temps but doesn't hold water in suspension.
DOT 3, 4 and 5.1 are polyethylene glycol based. DOT 5 is silicone-based and does not mix with the polyethylene glycol based fluids.

If the car had either synthetic or silicone and someone accidentally mixed the two, the seals in both the calipers and the master cylinder would slowly be destroyed and need rebuilding. To boot, in order to change from one type of brake fluid to the other requires a thorough flushing of all lines and cylinders before adding the new fluid.

Seems like you've tried everything else. This is the only thing left.

[Akimbeau]

Originally Posted by jhv48

Next question. Did you buy the car from someone or are you the first owner? When you got the car, did the brakes work correctly? What type of brake fluid did it have in it? Most come with DOT 3 or 4, though some have 5.1. If the car was setup for racing, it might have used DOT 5 fluid, a silicone based fluid that works better in higher temps but doesn't hold water in suspension.
DOT 3, 4 and 5.1 are polyethylene glycol based. DOT 5 is silicone-based and does not mix with the polyethylene glycol based fluids.

If the car had either synthetic or silicone and someone accidentally mixed the two, the seals in both the calipers and the master cylinder would slowly be destroyed and need rebuilding. To boot, in order to change from one type of brake fluid to the other requires a thorough flushing of all lines and cylinders before adding the new fluid.

Seems like you've tried everything else. This is the only thing left.

The brakes have been totally rebuilt and all fluid has been changed. I have always used Dot 4 synthetic.