cant get rear brake piston back into the caliper

90tbirdsc

Registered User
basically what the title says, I took my rear brake calipers off and accidently touched the pedal when they were off the rotors. ive screwed them back in as far as they will go and still not enough clearance for the stock rotors. I even opened up the bleed screw and put a c clamp on it. once again no luck, nothing moved. I need about 1/4 more clearance and they wont move at all.

Im not sure what else to try, some people say if you cant turn them in with just simple pliers your calipers are shot anyways. they only have 86000 miles on them only being drove in the rain 2 times, and that's with me owning it. it isint a daily driver. so it seems unlikey that they are ruined unless I messed them up somehow?:confused:

any help is appreciated, thanks
 
Well you do literally have to turn them while pushing on them. It's tough but you can do it with a needle nose pliers. There is the correct tool you can rent to do it also from autozone. Maybe you should try that first.

Chris
 
Well you do literally have to turn them while pushing on them. It's tough but you can do it with a needle nose pliers. There is the correct tool you can rent to do it also from autozone. Maybe you should try that first.

Chris

I had channel locks to twist and I was also pushing with all my strength and still won't move. I'll try the tool and see I guess.
 
basically what the title says, I took my rear brake calipers off and accidently touched the pedal when they were off the rotors. ive screwed them back in as far as they will go and still not enough clearance for the stock rotors. I even opened up the bleed screw and put a c clamp on it. once again no luck, nothing moved. I need about 1/4 more clearance and they wont move at all.

Im not sure what else to try, some people say if you cant turn them in with just simple pliers your calipers are shot anyways. they only have 86000 miles on them only being drove in the rain 2 times, and that's with me owning it. it isint a daily driver. so it seems unlikey that they are ruined unless I messed them up somehow?:confused:

any help is appreciated, thanks

Our ratcheting calipers suck to start with. If you hit the brake pedal while the caliper was off and the piston popped out you need to get a new caliper.
 
This is fixable. The problem is that the pin the piston rides on is not fixed in the cup. This means that when turn the piston it is possible that the threaded pin that it screws in on can turn also meaning that it doesn't screw in. To overcome this problem, the best thing to do is put inward pressure on the piston while turning. Also, make sure that your Ebrake lever (on the caliper) is in the correct position. It might have rotated too far and might be binding on the pin. Compare it to the other side for reference.
 
This means that when turn the piston it is possible that the threaded pin that it screws in on can turn also meaning that it doesn't screw in. To overcome this problem, the best thing to do is put inward pressure on the piston while turning. Also, make sure that your Ebrake lever (on the caliper) is in the correct position. It might have rotated too far and might be binding on the pin. Compare it to the other side for reference.
Ah ha! So thats why I have to tap on it with a hammer and twist it at the same time I can get it to seat. Thats tap.. guys.. not smash! Twist some.. tap some.. twist.. tap. Eventually it gets seated.
 
Ah ha! So thats why I have to tap on it with a hammer and twist it at the same time I can get it to seat. Thats tap.. guys.. not smash! Twist some.. tap some.. twist.. tap. Eventually it gets seated.

Having the proper tool helps a bunch. I used to have a universal like they sell at the parts stores and that worked about 2x before it stripped off and caused much cussing. The right tool fits the notches perfectly and doesn't slip.

Then the next trick is to install the caliper on the car without the rotor so you can actually push on it while turning. This has worked 100% of the time. Steady firm pressure and turn it with a big wratchet. ;)
 
If you're not interested in buying the right tool for the job, a lot of auto parts stores will rent it to you. Though if you do rear brake jobs even once a year on vehicles with calipers that have the e-brake integrated into them it's worth having on hand, IMO.

22389d1354073138-MR2-rear-brake-piston-disc-brake-caliper-tool-set-hx-aut002-.jpg
 
If you're not interested in buying the right tool for the job, a lot of auto parts stores will rent it to you. Though if you do rear brake jobs even once a year on vehicles with calipers that have the e-brake integrated into them it's worth having on hand, IMO.

22389d1354073138-MR2-rear-brake-piston-disc-brake-caliper-tool-set-hx-aut002-.jpg

I got that and tried it, wouldn't budge. any caliper upgrades for stock sized rotors in the rear?
 
I've always managed to get it done with a set of channel lock pliers and a hammer. :D Channel locks on the top ridge, not the surface that slides past the rubber seal. Twist.. twist.. tap a few times.. twist some more, repeat.
 
rear calipers

When I did mine they wouldn't budge when I tried. I sprayed some PB blaster around the piston while lifting the seal gently. I then opened the bleeder and was able to turn with needle nose pretty easily. A gentle tap with a hammer helped too..
 
WOW! This brings back memories... I am a perfectionist, so I will do it right and get a caliper rebuild kit. I just checked and AutoZone sells them for our cars. It is much easier to do the job with the calipers removed but I have done them while still bolted in the vehicle (but not a SC)...

It has been a long time since I purchased a brake caliper kit. I remember back then you buy the kit, hone the cylinder and replace the seals. You need to make sure you thoroughly clean the pistons and cylinder bore. I always used to a hand held drill mounted brake cylinder hone. While holding the tool perpendicular, I would hone just enough to insure the cylinder walls had no scratches or to remove any contaminants. No more...
pic10.jpg


If you manhandled the pistons you may have to de-burr the edges of the piston with 600 grip emery.

To instal the piston I use caliper grease and a large C-Clamp to apply even pressure while turning (possibly a small wood block to protect the piston top) in reinstalling the piston.
bigclamp.jpg

The above is not my clamp but an example...

If the calipers are is still in the vehicle you will need to relieve some brake pressure by cracking the bleed. When you are done you will have to re-bleed the entire system (all 4 wheels) to remove the trapped air.
:cool:
 
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