Is it possible to reset (push back) the brake calipers without bleeding the brakes? I removed the pads and while the new ones arrived, someone (probably me) pushed the brake pedal and the pistons got close to the disk. Now I cannot slide the new pads into the rails.
Any help will be greatly appreciated. Thank you.
Wrap a long flat head screwdriver with some tape, open the master cylinder reservoirs* and push the screwdriver against the disc into the piston. Using the shaft of the screwdriver not the end
A lot of people don’t like this because it may damage the piston, however I have done it like this for years with no issues.
You could conceivably take anything long and thin and just push the piston back in. The piston is magnetic so be careful to make sure nothing gets stuck to them.
Edit, check your brake fluid level as well, chances are you will introduce some air especially if you open the reservoir.
*typically you can push it back without having to open it.
As long as the piston hasn’t come out of the bore, you can easily push them back in. I would try to push only on the edge not on the magnet as they can be brittle. If you haven’t added brake fluid, more than likely you shouldn’t have an issue at the master cylinder. If you have added fluid, you will have to get rid of the displaced fluid.
Thank you both, it worked! I opened the reservoirs and the fluid was low. as I pushed the pistons the fluid went back to level. Installed the new pads, closed the lids and pedal stiffness is good. I will keep monitoring for potential air in the lines but so far I will take this as a win. Thanks!!
Which method did you use to push back the pistons?
There’s spreader tools made for full-sized car brakes that could work here. Just make sure the plates on it will fit in your caliper.
Some super basic screw-type ones from Harbor Freight to nicer leverage ones from race supply places like Summit, et al. You basically pull the caliper, put in old brake pads you don’t mind marring, then spread the tool to push the pistons back.
caliper piston spreader
is the Google term.
Sometimes snap-ring pliers can fit in there to do some spreading.
