Front discs dragging

[72 tigger]

My 72 C-10 I’ve been working on has developed a front brake issue. They were working fine but the last few times that I’ve moved it in and out of the shop the discs are dragging bad enough that I can’t turn the wheels when I jack it up. I may need to clean the caliper slides since I did paint them? I have opened the bleeder screws and it doesn’t seem to be under pressure (fluid does come out) but I still can’t turn the rotors. Open to any suggestions- thanks

[truckster]

The slides should be cleaned and greased. Since you've opened the bleeders, the other possibility I can think of is that your pistons are binding.

[Steeveedee]

If the bolts are corroded, they can cause that. Clean everything up and lube it all. Are the hoses recent? Old flex hoses can cause this, also. Did you replace the master/booster or anything that might change the stroke so that there is now a rub?

[72 tigger]

I did replace the master and booster (l saw the rod length can pose a problem in another post) the strange thing is, they worked correctly for a while and then started dragging. If I loosen the master cylinder nuts, that should release the pressure if the rod is too long- correct? Thanks

[hugger6933]

yes that was gonna be my suggestion loosen the mc nuts and see if the problem eases. I have had this happen to me on things from 71 Chevelles to 05 C1500 trucks

[RichardJ]

>> I have opened the bleeder screws and it doesn’t seem to be under pressure (fluid does come out) but I still can’t turn the rotors.<<

If you have cracked the bleeder, relieving the hydraulic pressure, then you have eliminated everything before the caliper. (hose, metering valve, MC and booster.

The caliper has to float on the pins(bolts). The piston seal should relax and withdraw the piston about .004' when the hydraulic pressure is removed.

Go back up to post #2 by truckster.