Guys I'm having an issue with my brakes and I'm not so sure what else should I try The last year the car brakes starting to loose power at the point the wheel will never lock no matter how hard I step on the brake pedal. I though it was due to the front caliper where in need of rebuild so I did it and now the calipers are rebuilt but nothing has changes the brakes are still not safe enough like they used to be. I tried bleeding all four wheels, adjusting rear brakes and there was a tiny improvement but the brakes aren't the same. When I had the car back on the road one of the first things I did was replacing the master cylinder because the old one was leaking and the brakes were excellent but now that's gone. What else should I check? Maybe a vacuum bleeding will help?
Did u bench bleed the master cylinder Is there alot of fluid coming out when you bleed the rear is it a good solid amount of fluid. I had a problem as well it ended up being the rear rubber hose was bad above the rear end inside the actual hose itself
I forgot to tell, all hoses are new About the master cylinder I don't remember If I bleed it and how much I did it. But I guess I did it or the brakes would have always been as bad as now
master could be bad......it s gauge and see how much pressure is being made. masters are under 100 bucks
Power brakes? Booster could be on its way out if so. I'd dissconnect the 2 lines right at the master, then bleed master while on car, reconnect lines, bleed rear then front, (farthest from master first and so on...) and see what ya got then. There is a switch on the front of the proportioning valve that has to be pushed in while bleeding on disc/disc or disc/drum. Good luck, Jim/Rott
The booster was inspected 5 months ago and its seals were serviced, I think booster doesn't has anything to do here mostly because there are no vacuum leaks and the brake pedal feel softy so I think the booster it's doing his job What's the purpose of the proportioning valve switch? When I removed the proportioning valve when changing a leaky brake line I dont remember of seeing something like a switch there
Im a little confused here. If you put the car on jackstands and step on the brake pedal, do all the wheels lock up? In other words, wit the brake pedal depressed, can you spin any of the wheels? What do the drums and rotors look like? If the drums, rotors, pads and shoes are glazed (shiny smooth), the brakes will have minimal stopping power.
With the brake pedal pressed I can't turn any of the 4 wheels, all of the brakes are working but the brake effect on "panic stops" is just not the same that it used to be , the brake pedal completely sink and the stopping power came just when the pedal is barely to the bottom even at 30mph feels a bit scary trying to stop the car. The rear brakes were serviced like 7 months ago but I disassembled everything yesterday inspecting what could be wrong and the drums looked good to me That's the valve that's mounted on the car frame, but what's the valve that is mounted just one side of the master cylinder and what's it's purpose?
Then I would recommend examining the rotors, drums pads and shoes. Sounds like they have no friction. Hold off valve. It holds off the disc brakes from working till the rear brakes start to work
Sound's like air in the lines to me. When you bleed them did you have nice streams of clean fluid coming out?
That's another thing we need to nail down- what kind of pedal do you have? Pedal shouldn't be low. When your stepping on the brakes, you shouldn't be able to compress the pedal. Brake fluid doesn't compress.
it sounds like the proportioning valve to me . bleed front and rear at the valve .your probably only getting pressure on one end or the other.
The shoes could also be a long ways from the drum. I think you should only have one and a half rotations when you spin each tire with good bearings off the ground.
If you pump the brake a couple times then slam on them and it feels better, then it is likely air in the lines.
Re-bleed the brakes. My new method for stubborn brake systems: Helper in car, you by furthest wheel from master... right rear, open bleeder, then have helper depress pedal all the way and hold it, you close bleeder, helper releases pedal. repeat for left rear, right front then left front. Check fluid level in master, go around and do it again till the stream is solid, no spitting/splattering.
If I pump the brakes while trying to brake I feel like nothing improves but today went out for a ride and after a moment of driving downhill the brakes starts acting a bit better but still not really safe. According to my knowledge if the brake circuit has a lot of air the pedal fade should appear really quickly when the brakes came hot, so today on a really lonely road I drove like 10 - 12 miles downhill just using brakes for stopping the car (car always in neutral) and the pedal fade never showed so that's confusing me even more I always adjust drum brakes until I feel the shoe making friction with the drum but not so tight that I can't turn the drums by hand Yesterday checked the master cylinder fluid level and bled all four wheels, this time first bled the master cylinder, then the valve that's attached to the master cylinder, then the proportioning valve (I didn't find any switch on it), then rear brakes and then front. The brakes improved a bit after this but the brake pedal still sinks almost to the floor with barely touching it and the brake action just starts at the bottom
Did you mention that key piece of information before? If so I didnt pick up on it. Did you bench bleed the one you put on? Did you make sure the receiver cup in the back of the master was exactly the same as the old master's? If the master has a deeper receiver cup, the brakes will be almost to the floor. Ask me how I know this. If everything else checks out, they sold you a bum master
