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I'm having a terrible time trying to get the front brakes working on my m1009. Both front calipers won't fully release and are constantly dragging.
I just replaced the calipers thinking they may have had corrosion I the bores or something. Also replaced the pads and had the rotors turned and replaced the flex lines while I was at it. When I put everything together prior to bleeding the new brakes the hubs spin freely.
As soon as I bled the system, now the calipers won't release. I can spin the hubs but it takes both hands and significant effort to get it to move.
It seems like there is a restriction in the system somewhere that is preventing the return spring in the caliper from retracting the piston, but I have no idea how to troubleshoot further without just throwing parts at it. Is there a way I can test if it's the proportioning valve, master cylinder, brake booster? Any advice would be appreciated.
Loosening the bolts between the master cylinder and booster does not cause the brakes to release. Opening the bleeder screws on the calipers allows fluid to begin seeping out, but also does not release the brakes. With the bleeder open it seems like any residual pressure should escape and the caliper should release, but they do not.
Also when the rotors came back from being "turned", one now has 0.015" runout and the other has 0.040". I need to check the TM for the spec, but I doubt it's more than 0.002"... I didn't measure before I took them off, but I can't imagine they could have been that bad before. The truck drove and stopped fine other than the constantly dragging brakes and I'd expect rotors that badly out of true to cause the pedal to pulse pretty badly.
Is my next step to press the rotor back off the hub and measure the runout on the back flange of the hub?
I just replaced the calipers thinking they may have had corrosion I the bores or something. Also replaced the pads and had the rotors turned and replaced the flex lines while I was at it. When I put everything together prior to bleeding the new brakes the hubs spin freely.
As soon as I bled the system, now the calipers won't release. I can spin the hubs but it takes both hands and significant effort to get it to move.
It seems like there is a restriction in the system somewhere that is preventing the return spring in the caliper from retracting the piston, but I have no idea how to troubleshoot further without just throwing parts at it. Is there a way I can test if it's the proportioning valve, master cylinder, brake booster? Any advice would be appreciated.
Loosening the bolts between the master cylinder and booster does not cause the brakes to release. Opening the bleeder screws on the calipers allows fluid to begin seeping out, but also does not release the brakes. With the bleeder open it seems like any residual pressure should escape and the caliper should release, but they do not.
Also when the rotors came back from being "turned", one now has 0.015" runout and the other has 0.040". I need to check the TM for the spec, but I doubt it's more than 0.002"... I didn't measure before I took them off, but I can't imagine they could have been that bad before. The truck drove and stopped fine other than the constantly dragging brakes and I'd expect rotors that badly out of true to cause the pedal to pulse pretty badly.
Is my next step to press the rotor back off the hub and measure the runout on the back flange of the hub?
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