I attempted to change my rear brake pads last night. Removing the caliper (brakeline still attached) was the easy part, but the dam brake piston would not screw back. I didn't have the nifty little tool, so I used a pair of pliers to turn it clockwise and after some effort it finally spun. Unfortunately, after a couple dozen turns it only moved 1/8" inward and would not go any further no matter how much I continued to spin it. I even tried counterclockwise, which just moved it back out.

Not sure if this has anything to do with it, but initially had the e-brake on, but I had to disconnect it to remove the caliper. I don't think it matters, but wanted to note everything in case it might help determine my problem.

The brake system, including rear brakes worked fine before. The pads were getting low and it was only general brake maintenance. Please help.

1. Should piston be turned clockwise or counterclockwise?
2. Do I need to remove the brakeline?
3. Where can I rent/buy that special tool?
4. Tips/Tricks/Advice?

Thanks!

 

1) I don't recall.
2) The e-brake should not be engaged. The brakeline itself should not be touched. I like to use a long zip-tie to ***her it to the spring so I don't have to worry about dropping it on the brakeline.
3) AutoZone and Advanced Auto both had them, last I checked. Autozone also has a rental tool which both presses and turns for better effectiveness.
4) Clean it good with brake cleaner. Make sure the slider pins on the calipers move well. Also make sure both parking brake cables move freely.

 

The piston should be turned clockwise. I've also read to take the top off the master cylinder in order to relieve some pressure on the system.

 

Thanks! I tried all the above last night and the piston still won't moving in any further. Wrestled with it for two hours and it was too late to go buy a brake bleed kit I really don't want to touch the brake fluid if I don't need to and the caliper worked fine before, so I don't want to spend more money on a new caliper if I don't need to.

 

I still need help. Thanks!

 

loosen the bleeder valve on the caliper and give it a try, beware, fluid will squirt.

 

You should get the correct tool and it will be easy--I'm serious. I cannot explain because I have only done it on two cars, but it's just one of those things where with the right tool it is so ridiculously easy. Without, and I don't know why, it seems difficult. I could not turn the piston with pliers.

Think about what you said--the brakes worked before you took them apart. How do you know? Because when you pulled the parking brake, the car stayed-put. When you released, the car rolled. That shows the pistons work.

I bought the tool for $35, but I heard you can rent it for free. Good luck. This link shows the tool is $69, but if you shop around it's $35.

http://www.menintools.com/ast7860.html

 

Hey Frank,

I was able to turn the piston with just the pliers (alot more work), but my problem is that I couldn't get the piston to retract more than 1/8". I could basically spin the piston for days and it didn't go anywhere.

I just noted the brake condition to clarify that my brakes were working before this dilemma. (just trying to troubleshoot)

What do you think about simply bleeding the brake to relieve pressure? Do you think this will allow the piston to retract?

Thanks,

John

 

i just did all 4 corners on my max, rotors and pads, and know exactly what you were talking about. i disconnected the rear calipers completely to work with it better, then used a pair of needlenose pliers to SLOWLY rotate the piston back in. ya, brake fluid slowly leaked out of the system, so be sure to either cap off the dangling line, or B, let it drain into a bucket and keep adding fluid while you are working on the caliper. might as well bleed it

 

Looks like you need new rear calipers.

 

Just called Kragen Auto and they have the tool for $12, but said I could probably do it with a needlenosed pliers. I told him about my problem and he said that I have to push in while I'm spinning. He said it shouldn't be necessary to disconnect the brakeline to do this.

I was too busy last night just trying to turn the dam pistion to notice if I was pushing in at the same time. I slipped a couple of times and was fortunate I didn't push the needlenose through my arm.

Anyways, anyone else change the rear pads with the special tool or pliers and can vouch for pushing while turning. Again, I don't think it's a bad pistion, but $12 sure beats getting raped for a caliper. I'd like to get fixed ASAP, since the pad wear indicator is already started to scream.

 

Definitely get the tool kit, it works like a charm. Looks like this:
http://www.sjdiscounttools.com/ap7860.html
I rented mine from Auto Zone, you just put down a $35 deposit and they'll refund you in full whenever you bring it back. The adapter that they sell for like $8 doesn't seem like it'd work too well, so just get this kit. I didn't have much luck with the needle nose pliers either, but I'm willing to bet you'll be able to get the piston back in if you just use this. I thought I had the same problem as you when I tried the rear calipers. Just keep the Master cylinder reservoir cap unscrewed and have someone check to make sure it doesn't overflow (it shouldn't rise too much though for the rear pistons). It should do the trick though.

 

They didn't have the special tool kit at Kragen's or Pep Boys, so I just got the $12 one from Kragen. It's basically a metal box with six different paterns on each side to fit different applications. You use it with a 3/4 socket wrench and voila. It was way easier and I got the job done in about 45 minutes for both sides. You definitely need the right tool for the right job.

Thanks again for everyone who responded.

 

See you dont come to a sword fight with a pen. Always buy the right tools.

 

I don't know what kind of advice that is, since advice often brings me to a pen fight with an expensive sword I didn't need. Or, when the 'right' tool only results in getting done a little faster. Unless you're running a shop, I could spend thousands of dollars on the 'proper' tools just to make 60k and 120k maintenance.

I think in this case, the condition of the caliper dictates the kind of tool you'll need. If Autozone is anywhere nearby, then it's a no-brainer since it's a free rental.

Dave