nemesis25

I'm in the process of changing the brake rotor and pads on my 92 Honda, Prelude. And, for the life of me I can't get the piston to go back into the caliper bore. I actually, bent a C-clamp trying to get it to go back in. So, my question is, what am I missing?
Thanks.

ml21

on our preludes since the rear braks also play the role of the ebrake the pistion isnt a push type its a turn type so you gota turn it clockwise to get it to go in kinda like a screw. they do make specialty tools for this big a big screw drive should do the trick it has for me at least.

Hawkze_2.3

Yep, the rears have to be screwed back in.

minilogoguy18

A good trick I learned if you don't have the tool is to use needle nose pliers with them slightly opened you put each end in a slot and spin the piston in.

DCFIVER

Front or rear? If it is the rear this has been asnwered, if the front, you may have cocked the piston in its bore.

nemesis25

Actually, it's the front ones. I suspect so, or might be frozen. But then again both of them wont go back in?

InvaderTrax

Are you pushing them perfectly straight? Did they move at all?

Enzo15

Make sure your using a old pad between the piston and clamp so that you dont damage the piston, or get the tool that compresses them, its like 10 bucks at auto stores. those work well.

Phildo916

Did you open the brake master cylinder to allow the system to decompress and allow the movement of the pistons back into the calipers?

nemesis25

Yes, I'm pushing them straight, but no movement. Also, I used the old pads to push them back in. And, I did open the master cylinder to relieve pressure.

lazlong

$8 at Autozone:


If that doesn't work:
1. Pull the whole caliper off and plug the brake line
2. Put a piece of wood between the piston and other side of the caliper (so it doesn't hurt the piston when it comes shooting out). Then turn it over and lay it down so the wood is on the bottom.
3. Shoot compressed air into where the brake line enters the caliper and BAM the piston is free.
4. Replace the piston ring/gasket, lube the piston bore and re-insert the piston.

***I can't stress enough how important it is to turn the caliper upside-down. If you leave it rightside-up then that piston will shoot out and hurt or kill someone. My cousin shattered his cheek bone one time doing it that way.

Enzo15

As a total last resort if the compressed air doesnt work to free the piston like it was said ^^^^^ Then you have to use hydraulic fluid, ie: Brake system, to free the piston.... or just get a whole new caliper.

razorlude

if the piston was being pushed in slantingly and stucked,there's a m8 screw at the back of the caliper reservoir where u can put something in to knock or realign the piston position.i suggest u knock the piston out,make sure the cylinder wall is clean n clear free of rust(especially on the groove where the new seal seat in.put back the seal,then lube the whole internal with brake fluid only!(hydraulic oil will deteriorate the rubber seal ok),make sure the bleeder or the screw aren't tighten so u r not working against air pressure, push the piston in gently with some constant turning movement on the piston,there's a cross on the head the piston so ask a flat head to help you...and yes the dust seal,always install on the caliper side first then only the piston side when it's about to get there.

good luck bro.

Enzo15

Please read next time. He is having problems with the FRONT calipers not the rear. This has been covered already.

razorlude

my bad...