rear caliper question

[sgarlic]

Hi guys. You may remember a week or so ago, I crossthreaded a lugnut in the rear, and finally got around to messing with it today.

I got the car up, wheel off, broke the lugnut and wheelstud off, etc.

I then planned to just remove the caliper and rotor, replace the stud, etc. Well, I looked through my service manual CD, looked online, etc.. most places just say "remove caliper" without much further info.

The ordeal is, we broke loose that main top bolt on the back of the caliper, then couldn't break that big bottom one loose.. since that line is right in the way, there was no way to wedge a box end wrench or socket in there.. we thought we got it loose, but turns out it was just the open end wrench stripping.

So, my buddy got this idea to just remove the two smaller bolts holding what appears to be the center of the caliper to the outside. Do these need to come out? And how the hell do you get that bottom big bolt out?

 

[Mike97gt]

first remove the two bolts that hold the caliper to the caliper bracket. ( thse are the top bolts that have 10 mm heads.

then remove the caliper and pads by prying up with a prybar. then you can get to the 2 15 mm bolts that hold the caliper bracket to the rear end.

DO NOT REMOVE THE BOLT HOLDING THE BRAKE LINE ON.

 

[BennyBlown2v]

DO NOT REMOVE THE BOLT HOLDING THE BRAKE LINE ON.

If you do you'll have to bleed your brakes!

 

[sgarlic]

The two smaller bolts I was referring to that my buddy wanted to remove were some weird size. A 13mm was almost the right size, but was a little too big.. 12mm was too small.. a 7/16 was too small, and a 1/2 was too big.. if you follow the head of the bolt, it runs through the caliper through a little rubber boot.

 

[sgarlic]

Welp, got it all done.. we managed to get the caliper and crap back on when done without compressing the piston, and it appears now that the brake is rubbing.. great.

 

[triggz]

The two smaller bolts I was referring to that my buddy wanted to remove were some weird size. A 13mm was almost the right size, but was a little too big.. 12mm was too small.. a 7/16 was too small, and a 1/2 was too big.. if you follow the head of the bolt, it runs through the caliper through a little rubber boot.

thats the bolt you need to remove. prying the calipers off without loosening those will make it near impossible to get them back on.

it sucks to get to because of the e-brake line, i know. i dont remember what size it is, but youll have to use an open-face wrench to get it off. im pretty sure its 12/13mm.

 

[triggz]

Welp, got it all done.. we managed to get the caliper and crap back on when done without compressing the piston, and it appears now that the brake is rubbing.. great.

a small amount of constant friction is normal..but you should be able to rotate the wheels with one hand with a little effort.

if the caliper isnt compressed flat it can cause rubbing one on side of the pad and uneven wear

 

[Mike97gt]

a small amount of constant friction is normal..but you should be able to rotate the wheels with one hand with a little effort.

if the caliper isnt compressed flat it can cause rubbing one on side of the pad and uneven wear

+1

the pads are always going to touch the rotors.

remeber if you do have to compress these calipers they twist in not push in.

 

[sgarlic]

Ok.. I think I just need to rent or buy the little tool to compress the caliper piston back in. It seems like the piston was just barely poking past the side, but somewhere during the messing around of the replacing the wheel stud, I accidentally yanked up the ebrake not thinking.. I'm guessing that's what caused the piston to come out.

I did check (crudely) with a thin cardboard razor blade cover to see if the pad was contacting the rotor when the brakes were not engaged, and found that the piece of cardboard wouldn't slide between the pad and rotor on any of the brakes.. however, the rotor I was working with is definately a LOT hotter after driving than the rest.

I'd feel much better if I just rechecked that caliper. We got the caliper started on the rotor, then had to use a mallet to hit alternate sides of the caliper until it was fully seated.. I don't recall ever having to do that before.. so I'm guessing the piston is just rubbing a little bit more than it should.. I'll get that tool tomorrow and push the piston back in. I can just remove the master cylinder cover when I compress the piston to relieve the pressure, right? I'd rather not open the bleed valve unless I absolutely have to. (I don't have ABS if that makes a difference.)

 

[Kilgore Trout]

People never clean and grease the grooves in the bracket that the tabs on the pads ride in. You should do that

The slide pins should be cleaned and greased also.

Use high temp moly grease.

 

[Mike97gt]

Ok.. I think I just need to rent or buy the little tool to compress the caliper piston back in. It seems like the piston was just barely poking past the side, but somewhere during the messing around of the replacing the wheel stud, I accidentally yanked up the ebrake not thinking.. I'm guessing that's what caused the piston to come out.

I did check (crudely) with a thin cardboard razor blade cover to see if the pad was contacting the rotor when the brakes were not engaged, and found that the piece of cardboard wouldn't slide between the pad and rotor on any of the brakes.. however, the rotor I was working with is definately a LOT hotter after driving than the rest.

I'd feel much better if I just rechecked that caliper. We got the caliper started on the rotor, then had to use a mallet to hit alternate sides of the caliper until it was fully seated.. I don't recall ever having to do that before.. so I'm guessing the piston is just rubbing a little bit more than it should.. I'll get that tool tomorrow and push the piston back in. I can just remove the master cylinder cover when I compress the piston to relieve the pressure, right? I'd rather not open the bleed valve unless I absolutely have to. (I don't have ABS if that makes a difference.)

you should NOT be able to slide anything between the rotrs and pads. they are supposed to contact at all times. if they did not contact at all times your pedal would go right to the floor before enough presure to slow down the rotor would be applied

just recompress that caliper if it makes you feel better.

 

[sgarlic]

Well.. unless only that rotor being much hotter than the rest after a 15mph trip of less than a mile with one stop sign is normal, I'll double check the caliper.

 

[CRZYHRSGT]

You might have a pad sticking. Like Kilgore said, you need to clean and lube the area of the bracket where the pads slide. I just came in from the garage a couple of hours ago from putting Bullitt front brakes on and painting/new pads and rotors on the rear. I couldn't believe how caked up the brackets were with rust. There would have been no way that the pads would have been able to move properly without me scraping/cleaning/lubing them.

 

[sgarlic]

Well I took it all apart again today. Bought that little cubed shape caliper tool, which didn't have the correct size on it anyway.. so I ended up using a needle nose to spin the piston back in (about one 365* turn and it was fully in.)

Took it for a very short drive, and noticed the rotor was only a little hotter than the other rear rotor.. perhaps it'll take a bit of driving to fully return to normal or something.

Thanks for the advice guys.

 

[Mike97gt]

as long as the temps are close you will be ok.