No, opening the bleeder does not help.i disconnected the line at the master cylinder still not releasing. Think the new caliper is defective?
Caliper not releasing
- Thread starter Fred A
- Start date
You have done the test for a locked caliper, popping the bleed screw releases pressure to the system and eliminates a bad brake hose or brake line as the cause of the lock up. There is a problem with the internals of the caliper.
Dave
^This^
Anyone know what size the end fittings are for the driver side brake line?
68yourker
New Member
The problem you describe, can be either hydraulic or mechanical. On the hydraulic side, could be bad brake hose, plugged brake line, master cylinder not returning back all the way up (this opens compensate ports in the master cylinder which allow the fluid to return to the reservoir and refills the lines), or lines reversed at the master cylinder (rear drum brakes have a residual pressure valve that holds about 10 PSI in the line to prevent air from getting drawn into the system from the lip seals in the wheel cylinders). It could be a mechanical problem in the caliper or rotor. The reason you open the bleeder screw and see what happens, allows you to divide the system between mechanic or hydraulic. A hydraulic problem will allow the rotor to turn AFTER you open the bleeder screw (any of the above hydraulic situations will allow fluid pressure to stay trapped at the caliper holding it on-until you open the bleeder which will eliminate that pressure). You said it still will not turn after the bleeder was opened. My suggestion is to remove the caliper, and see if the rotor turns freely. Could be a mismatch of parts (could be the rotor doesn't have the same offset as the caliper causing one of the brake pads to drag all the time-this will be eliminated by removing the caliper and see if the rotor will spin). If the rotor still doesn't spin, could be wrong bearing, seal or spindle. No silver bullet but a way to check the system step by step. Too many expensive parts to just start throwing parts at it.
HTH
HTH
When I remove the caliper the rotor spins freely. You think it still can be the caliper? It is remanufactured by Cardon.
Just Carbs
Well-Known Member
Your bleeder valve test indicates a bad caliper. Disassemble the caliper if you want to know what's wrong with it.
Otherwise return it to the store for an exchange or refund.
Otherwise return it to the store for an exchange or refund.
68yourker
New Member
I would remove the caliper and brake pads, then set the caliper back on the spindle ways and ensure the caliper can slide freely. Then install the inner pad on the ways and ensure it can slide as well. This system works by the brake fluid pushes on the piston, which places the pad against the rotor (the rotor is fixed and cannot move in or out). The next thing that happens is the brake fluid is also pushing on the caliper housing to pull the outer pad against the rotor and now you have friction on both sides of the rotor. When you let off the brakes, the square cut seal inside the caliper (seal also keeps the brake fluid in the caliper) is suppose to pull the piston back in (only a VERY small amount) and releases the clamping force. If the caliper or brake pad doesn't move freely, it won't release. It could be the brake pad has excessive material around where it slides into the bracket, the caliper has a burr not allowing it to slide smoothly, or a caliper hardware problem. What happens if you push the piston all the way in, and then mount everything-will it spin freely? Don't step on the brake pedal. Can the rotor still spin freely?
Guys, I think it's calipers... Plural. As in both front calipers. And the old calipers were having this problem before getting changed.
@Fred A Is that correct? Both calipers? Were the pads changed at the same time?
@Fred A Is that correct? Both calipers? Were the pads changed at the same time?
Just Carbs
Well-Known Member
I'm taking odds on this one.
68yourker
New Member
I'm leaning towards the hardware. Do you have a picture of the caliper with it mounted on the car? These cars always had a little drag on the rotor. It was just the nature of the beast.
JimmyG
Member
I recently had an experience which was odd, but might be of interest to you. My front brakes would not engage properly or at an even rate. When they "hit" they hit hard and unevenly, causing pull towards which ever side was applying. They would also not release evenly or quickly. After much experimental pedal playing, a master cylinder replacement and much bleeding, I discovered that the brake hoses were collapsing internally.
No external cracking, just impeding the flow in and out.
I have learned that hoses do age internally, will collapse and impede flow, and usually impede flow as the fluid is released, in other words as the pedal is released.
I replaced both hoses, and shock of all shocks, the problem disappeared and both braking and steering returned to normal. A truly weird experience.
Given this experience, I also replaced the rear hose and found that it was impeded too. So, matters not if your hoses are new, look new, are relatively new, or are old,.....give it a try. Worked for me, and taught me a few things too!
No external cracking, just impeding the flow in and out.
I have learned that hoses do age internally, will collapse and impede flow, and usually impede flow as the fluid is released, in other words as the pedal is released.
I replaced both hoses, and shock of all shocks, the problem disappeared and both braking and steering returned to normal. A truly weird experience.
Given this experience, I also replaced the rear hose and found that it was impeded too. So, matters not if your hoses are new, look new, are relatively new, or are old,.....give it a try. Worked for me, and taught me a few things too!
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