Compressing brake cylinder

[scoobywagon45]

Hey so Im replacing my pads and Im having some major problems with depressing the brake cylinder so I can put the new pads in. I cannot use a c clamp because on the other side of the caliper where you would usually place it, it is a rubber boot so I cannot put it there or else I will tear the boot. Is there a special tool for this? I tried spinning the cylinder with a pair of channel locks but it has not depressed at all. Please help! im DOA.:-\

[MilesFox]

try pushing it in as you turn it. I generally use a channel plier. But sometimes it needs some pressure to 'thread onto' the mechanism that pushes it out with the parking brake.

 

You should be able to find a generic cube tool that is universal fit that goes on a 3/8 ratchet.

 

make sure the parking brakes are released when doing this

[l75eya]

I had the same problem when I did the front brakes on our Loyale. No matter how much I tried to get it to turn, it wouldn't turn more than like 1/8th of a rotation and with the new brake pads there wasn't enough clearance to get the caliper back on.

 

I wound up getting a new caliper. Might not have had to but it didn't seem like it was going to budge at all.

 

A pair of sturdy needle nose pliers you should be able to get the tips in the grooves on the piston.

[987687]

It also helps (and this is true for any calipers), to open the bleeder screw while you push or thread the piston in. This way you're just pushing fluid out the bleeder, not through the whole system.

 

You also don't run the risk of pushing dirt out of the caliper into the braking system. This is especially important on ABS vehicles. If you get crap in the pump, it gets not happy.

 

Sure you might get some air in the brake lines. But part of a proper brake service is bleeding, or even completely changing the fluid.

[l75eya]

Ha ha here i am in the future and i can NOT get the pass. Side brake caliper to compress at all. I've spun it a good 8 entire rotations clockwise and it hasn't moved in at all. Beautiful day to do the brakes shot because of this stupidity. Had to call it quits after getting a headache from my blood pressure boiling. Maybe next weekend with the actual crappy tool to do it with it'll get done.

[bendecker]

I put a large socket into the open part of the piston that pushes against the pad. The socket is just to take up space. I then use a C-Clamp to slowly compress it -- one end of the clamp on the socket, the other on the back of the caliper. Works every time.

 

If you have  rubber boot in the way, can you put something around it, like another big socket? I've never had that problem on my Brat, '93 Impreza or '96 Legacy that I recall. However, with the socket trick, you have a lot of different places you can put the C-Clamp, so you might be able to move it into a position where it doesn't muck with your boot on the back.

 

 

EDIT: This is incorrect for the Brat ^^^^. Sorry about that...

Edited April 8, 2014 by bendecker

[mudduck]

Ha ha here i am in the future and i can NOT get the pass. Side brake caliper to compress at all. I've spun it a good 8 entire rotations clockwise and it hasn't moved in at all. Beautiful day to do the brakes shot because of this stupidity. Had to call it quits after getting a headache from my blood pressure boiling. Maybe next weekend with the actual crappy tool to do it with it'll get done.

I have had this happen a couple times before. I was able to work the parkbrake mechanism while turning the piston to get it to catch the threads and get it to start turning. I did have the caliper off of the car and was working on it on my bench

[Gloyale]

I put a large socket into the open part of the piston that pushes against the pad. The socket is just to take up space. I then use a C-Clamp to slowly compress it -- one end of the clamp on the socket, the other on the back of the caliper. Works every time.

 

If you have  rubber boot in the way, can you put something around it, like another big socket? I've never had that problem on my Brat, '93 Impreza or '96 Legacy that I recall. However, with the socket trick, you have a lot of different places you can put the C-Clamp, so you might be able to move it into a position where it doesn't muck with your boot on the back.

 

Turning the piston has never done squat for me. Only the C-Clamp trick has worked.

 

It's an EA w/ front ebrake thing.  You have to turn the piston to run it back into the cylinder.  If you force it with a clamp you ruin the self adjuster in it.

 

Besides............There is nowhere to clamp against on the back of the caliper.  The E-brake mechanism, under a big rubber boot is on the back side.

 

If you did your brat that way I'm sorry......you ruined the self adjuster......you may have problems eventually.

[bendecker]

It's an EA w/ front ebrake thing.  You have to turn the piston to run it back into the cylinder.  If you force it with a clamp you ruin the self adjuster in it.

 

Besides............There is nowhere to clamp against on the back of the caliper.  The E-brake mechanism, under a big rubber boot is on the back side.

 

If you did your brat that way I'm sorry......you ruined the self adjuster......you may have problems eventually.

 

Good to know. I don't believe this applies to my '81, but I could be wrong....  I'd love a second opinion, though, f anyone else has knowledge.

Edited April 8, 2014 by bendecker

[idosubaru]

this isn't opinion, it's a fact.  the caliper piston is threaded into the caliper bore.  there's a steel threaded rod in the caliper bore - the piston screws onto it.  if you've ever rebuilt a EA caliper you've seen it. 

 

if you have converted brakes maybe they're different, but if your ebrake is still on the front then it's the stock set up.

 

what you're saying is exactly the same thing as saying you pound a bolt into a threaded hole without turning it.

 

on my first brake job i had no idea what i was doing and tried to compress the piston in - i was leveraging that clamp as much as i could, as hard as i could and the piston would not budge.  when i found out i needed that tool, i thought for sure i broke the piston based on turning it as hard i could.  so in my experience it won't go in without turning it.  and that makes sense - imagine trying to push a bolt into a threaded hole.

 

newer EJ stuff is not like that - nothing threaded, it simply pushes in place.

Edited April 7, 2014 by grossgary

[bendecker]

My apologies to everyone. I brain-farted on this. You are 100% correct on the Brat. I use the trick on my newer EJ's. They just gently compress.

Edited April 8, 2014 by bendecker

[Gloyale]

My apologies to everyone. I brain-farted on this. You are 100% correct on the Brat. I use the trick on my newer EJ's. They just gently compress.

 

It's cool.

 

I learned after ruining the adjusters in my first Soob (EA82).  I sucessfully compressed them with a C-clamp.............then replaced them 6 months later when the E-brake would not release.......

 

That was 1996.

Edited April 8, 2014 by Gloyale