Release brake pressure? Calipers are off and will not fit back over the rotor

I’m hoping someone can chime in? I just replaced the wheel bearing assembly. However, I can’t get the caliper back on because the pads are squeezed (by the pistons?). I tried pressing and releasing the brakes but I think that made it worse. How can I relieve the pressure and still have working brakes once I put it back together?

THANKS!!

 

Use a clamp to press the pistons back in. Just type "how to compress brake caliper piston" into google and a few videos will show up.

 

This is good advice, but he really needs this thing broken down Barney style and is bound to make things worse just by going at it that way. OP, put an old pad back in or something solid that can be used as an even surface between the dual pistons.and then compress in between both of them to distribute pressure evenly because if you push the piston in using that tool alone you will push out one even further.

To make things even easier, if you can afford to lose some brake fluid, crack open the brake bleeder screw and then push the pistons back in simultaneously, much less effort will be required to compress them back in and then once that is done, let the screw bleed out a little bit more fluid to prevent air from forming in the system. This method is called "gravity bleeding". Once that is done, tighten the screw and top off the master cylinder to replenish the fluid that you lost.

 

Is it safe for us to assume you've not done brake work before? Not being critical, just 'assuming', because the fix @12TRDTacoma gives is disc brake 101 stuff.

Yet you were bold enough to do the bearing assembly?

Good for you!

 

Yikes! Pushing the brake pedal was a very bad thing to do. I would be concerned that maybe the top left piston in the pic is pushed out too far.

 

Thanks everyone. I’ll give it a go with the clamps and loosen the bleeder valve. I do have some fluid so should be good. Hopefully I’ll report back with some good news.

 

Make very sure those pistons are straight in the bore, not cocked, before you start compressing. Or you'll be buying a new caliper.

 

Just noticed that you bent the Hell out of the hard line too.

 

This ^

 

That picture made me throw up a little in my mouth. Be careful not to get brake fluid on the pads or they're
R-U-I-N-T.

 

Take the top off the brake fluid reservoir and put a clamp on the pad and squeeze it back. Do both sides.

 

This, and go slow. Done it my entire life.

 

Thanks everyone for the quick responses. I am back up and running ... and dare say I'll do the driver side assembly tomorrow. I knew pressing the brakes was a bad idea ... right after I pressed in the brakes. The question earlier was asked if I've worked on brakes before. No, but I think most here will agree that learning and tinkering is part of the fun and this is such a great resource for information so thank you again.

I learned a few good lessons in the process.

• don't ever depress the brakes with the calipers off (duh) -- my fix was to a) remove the pads b) crack the bleeder screw c) clamp down the pistons ... they wouldn't budge. I went inside, had a beer, came back and they depressed with ease e) close the bleeder d) put the pads back in e) topped off the brake fluid ... and was back to the initial goal of the hub assembly.
• double check your tools before you start. I didn't have the simple 17mm wrench I needed (I had plenty of sockets) to get in the middle of the hub assembly to remove it

I knew I was going to have a problem with the brake hard line ... I couldn't for the life of me figure out how to loosen it until I realized the nut that holds the connector was simply sheared off. I can see it easily on the driver side but this is what I had ... so the line wasn't going anywhere and I did the best I could to disrupt it as little as possible.



Anyways --- thanks again everyone for the tips.

 

Here’s how to do the other side:

Use 2 big flat head screw drivers and drive the pistons back in before removing the caliper. No need to crack the bleeder. It’ll flow back to the master cylinder. Once the pistons are back in the caliper, disassemble and replace the pads. Once everything is back together, press the brake pedal a few times to get the caliper pistons out. That’s an important step; otherwise the first press of the brake pedal when driving will be a thriller as the pedal may go down to the floor. There’s more volume in the caliper for fluid than the master cylinder can provide in a single pump.

 

Hey good job man don’t let the little mistakes rattle you the next time it will be a lot easier.

 

Thanks again. Passenger side was MUCH easier ... but ... when I re-assembled the pads are rubbing on the rotors so I may have the same issue where i need to compress the pistons again and sort of reset the pads.but hoping it’s the dust shield ...
Thanks!

 

They will rub lightly. If you were able to get the caliper to slide on over the pads, they should be good to go.

 

I’m all set. The brake dust shield was rubbing. Easy fix. And holy smokes, the new bearing assembly is unbelievable. Thanks @05Taco4x4 for the great product! My test drive to drop off a borrowed tool was awesome. All this time I thought my tires were loud. Now that this is quiet I hear other noises ... slowly peeling back the layers. Lol.

THANKS AGAIN EVERYONE THAT CHIMED IN!

I was quoted $600 / wheel so I definitely saved some money, learned a ton, and am now looking forward to knocking out the other noises (probably starting with the idler pulleys).

 

Something like this is great to have. With 4 piston calipers, if you depress one side with a clamp, then the pistons on the other side may move out - and then you're in whack-a-mole mode
-

$32 Jetech Universal Disc Brake Piston Spreader Tool, Compatible with Cars & Motorcycles, Easy Brake Pad Replacement

https://smile.amazon.com/Jetech-Dis...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

 

I sure could have used that Saturday night . I knew I had to get the pistons depressed and am so glad people review and chime into these threads before I made any more mistakes. I'll definitely have one of these handy next time I'm working around brakes.