The brakes on my Rover kept locking so I replaced all the pads and also the callipers. It has been ok for a few weeks but has now started to seize again, any ideas? I can feel the car pulling as the callipers are not opening properly...please help.
2006-11-19 22:02:34 · 7 answers · asked by Anonymous in Cars & Transportation ➔ Maintenance & Repairs
When the brake pedal is pushed down, it forces the fluid out of the master cylinder into the steel lines, and on to the proportioning valve. This valve regulates the pressure between the front and the rear brakes, to keep the rear brakes from getting too much pressure. If the rear brakes gets too much pressure they will lock the wheels causing the rear end of the vehicle to slide around out of control. The pressure from the proportioning valve sends pressure down the frame rails of the vehicle to a distribution block. From this block pressure is sent down each axel to the wheel well. A high pressure hose then carries the fluid to the calliper on the front, and there is a hose for each wheel. Hoses are used because the movement of the wheels would break a solid line. These hoses attach to the callipers or wheel cylinders forcing the pistions outward when the brake pedal is applied. When these hoses become old, worn, frayed, or otherwise pieces of rubber hanging down on the inside (that you cannot see), the obstruction acts as a valve. Once you release the brake pedal, the pressure is no longer on the hoses, and the pressure returns to the master cylinder. If one of these hoses are bad, and a piece of rubber is hanging down inside the hose, it will let the pressure move one way because its under extreme pressure, but will not let it return when there is no pressure. It acts as a directional valve, not letting the fluid return to the master cylinder, thus keeping pressure on the one brake. Since there is no pressure to force the fluid past the obstruction in the other direction, a certain amount of pressure remains in the hose causing the brake to stay activated. This makes the brake drag, and the vehicle will pull to one side because the calliper/wheel cylinder cannot open back up due to the fluid not traveling back due to the obstruction. In other words the brake is working all the time, and the pad/shoe will wear excessively on the wheel that has the bad hose. This is a common problem, and most people make the mistake of replacing everything else thinking the calliper or wheel cylinder is locking up. Callipers/wheel cylinders very rarely ever lock up, unless they have been sitting a long time and rust up to the point of doing that. Now that you know how the brakes work, and that you have a bad hose somewhere, you should be able to resolve the problem.
I'm glad I could help. Good Luck!!!
2006-11-19 22:46:43 · answer #1 · answered by Anonymous · 1⤊ 0⤋
You must have bled the brakes when you fitted new callipers - was the fluid clear when you had finished? Did it pump through easily?
If these two points are OK it is the master cylinder not the callipers which is the problem. There is a valve in it which allows more fluid through to make up for pad wear. If this gets blocked it tends to keep pressure in the brake lines. Replace those seals and bleed everything again.
BTW did you remember to put a smear of 'Copperease' on the metal part of the pads - I put it that way in case you thought I meant the pad itself! - this lets things move smoothly and also prevents brake squeal.
RoyS
BTW
2006-11-20 18:55:31 · answer #2 · answered by Anonymous · 1⤊ 0⤋
Suggest you bleed the brakes to check the fluid is clear, if full of black stuff you need to completely recondition the system with new fluid and rubber pipes and possibly replace the faulty calliper too.
2006-11-19 22:14:10 · answer #3 · answered by Anonymous · 1⤊ 1⤋
Caliper pistons favor to be compressed. in the journey that they don't flow in actual, there is likely rust by the caliper. The dirt boot ought to get replaced to give up the leak. in case you do not fix it, sometime you received't have any brakes. best once you've an total 4 wheel brake overhaul - rebuild. you'll likely locate extra complications, and also you've been going to regulate pads in any case.
2016-11-29 07:27:01 · answer #4 · answered by ? 4 · 0⤊ 0⤋
Replace the rubber flexi hoses, they could be starting to break down inside causing a blockage and the symptoms that you describe.
2006-11-19 22:04:52 · answer #5 · answered by Goofy Goofer Goof Goof Goof ! 6 · 1⤊ 1⤋
you need to replace the break/caliper hose. if this does not work there will be a break/caliper valve thats sending too much preassure to the break caliper. if its your front breaks that are locking up your back breaks are out of adjustement. if its your back breaks that are locking up there over adjusted.
2006-11-20 01:50:21 · answer #6 · answered by milwmcnutt 2 · 1⤊ 1⤋
did you use some non melting grease on the slides?
2006-11-19 22:05:52 · answer #7 · answered by peter p 5 · 1⤊ 1⤋