Brake Problems

Jeez what would i do without forums...lol anywanys, I have a breez with disc brakes in front and drums in back. Once while driving the back left brake cylinder went out, which was a fun ride. but now every time i put a new brake cylinder on it blows again. blows meaning leaks from one of the boots. my only thought was the brake proportioning valve. any other thoughts? Thanks Shawn

Did you bleed the brakes on both sides when you changed the wheel cylinder. You could have air in the line on the other side forcing too much pressure to the new cylinder. What I would do if you have to replace it again is to replace both sides at the same time and as you stated replace the proportioning valve as well. Also make sure that none of the shoes is binding as it can cause an overpressure in the one side if it is binding.

Update, both the new cylinder and the old are leaking now... Both were bled. what do you mean by binding???

Make sure the brake shoes move freely when you hit the brakes, if they are catching on anything or just aren't moving freely they can cause the wheel cylinders to overpressurize and leak. Also make sure the drums are round. You may not feel it but if the drum is out of round it can cause a problem.

As for the problem at hand, are you sure that the parts store is giving you the correct cylinders. It is very uncommon to have wheel cylinders, especially new ones, to leak that rapidly.