C3 - SLUDGE

[Jim Markevitch]

I have sludge in the front section of my master cylinder. The rear is clean and clear. Any ideas of what is going on in my braking system?

[Jim T.]

Re: C3 - SLUDGE

Do you have DOT 3 or DOT 4 brake fluid in your master cylinder or DOT 5 silicone?
Conventional brake fluid absorbs water and the whole system should be flushed about every two years. Master cylinder fluid can be changed more frequently by just sucking it out, cleaning, adding new fluid.

[David H.]

Re: C3 - SLUDGE

On my 1980, some sludge had collected in the bottom of the master cylinder. The REAL SLUDGE however was in each of the calipers. They COULDN'T leak, the "brake fluid" was the consistency and color of day old Hershey syrup.

If it's in the MC, it's probably in the lines, junction blocks, and calipers.

I replaced everything: lines, hoses, calipers, junction blocks, master cylinder, and power brake booster.

In my case, I think the car had it's original brake fluid. The caliper pistons were corroded and caliper bores had rust pits. Don't believe the books and articles that say all calipers have been sleeved by now.