Rear Brake Caliper Problem

[Xero_Tolerance]

So I was trying to install new brake pads in the rear today because the old one on the driver side was scratching pretty bad recently. So I take the old one off and the one on the inside looks like it's brand new, but the one on the outside is down to the metal pretty much. So I tried to put the new pads in but they won't fit. After messing around with it for a while I just took the whole caliper off and was looking at it. The problem is the piston is pretty much fully out, like when it should be when you're braking and that caused it to rub the one side really bad and somehow the otherside doesn't get touched... The problem is I can't seem to get the damn piston to go back in, I've been trying to pry it closed and hit it with a hammer, nothing, there's no more fluid in there but the damn thing is stuck open. Any ideas what I should do in this situation?

I should get some pics later tonight.

Thanks.

 

[c5chris]

Use a mini vise, you can pick some up at your local Home Depot. It will retract with very little force used on the vise.

DO NOT hit the piston with anything.

 

[onepimpclipse]

Best $7 ever spent. Way easier than vise grips.

http://www.partsamerica.com/PartDet...PO&MfrPartNumber=T718991465&CategoryCode=3479

 

[oldman]

The piston doesn't go straight back, you have to turn it and push at the same time. Don't hit it with a hammer anymore. If you look at the end of the piston you should see it's not flat and have markings on them. I forgot what they're call but there's an adaptor you can buy that fits those markings which will allow you to push and turn at the same time. Just ask your local parts store who carries a lot of specialty tools, they should know.

 

[Xero_Tolerance]

Well I bought that brake spreader thing from advance, but the piston is seriously stuck, it won't go down at all after trying to twist it as hard as I can... Any other thoughts on how to get this thing unstuck, or why it would be stuck...

here's a pic of it right now

http://filebox.vt.edu/users/rengle/mycar/caliper.jpg

kind of blurry, but you can see it's pretty much fully extended, the piston that is.

 

[oldman]

You've mention in your original post that only one side was worn out, sounds like the driver side is stuck. You probably need a replacement caliper.

 

[Xero_Tolerance]

That's what I was afraid of... I guess it's possible the piston is rusted in place maybe? I mean shouldn't there be a way to free it, all it is is a piston that gets pushed when you apply pressure to it... Eh, I guess I can find a replacement pretty cheap, but does anyone know if it would be really bad to drive the car without brakes on that one wheel, I still have the front two and the rear passenger side one so it doesn't seem to me like it would cause too much trouble, obviously braking wouldn't be as good but I think it would still be ok... I guess all I'd have to do it make sure the line is closed tight so there's still pressure for the rest of the brakes.

 

[DiabloRT]

AS PREVIOUSLY STATED THE REAR CALIPER PISTON GETS TURNED IN

YOU CAN NOT PRESS IT BACK IN LIKE THE PISTON IN THE FRONT.


They sell a small cube type tool. A 3/8" drive extension fits into the cube and you use a rachet to turn it. Each side of the cube has two pegs sticking out of it. One side will fit the grooves in the piston face the best. Engage the best pegs in the groves and turn the piston in clockwise.


You also need to clean and lube your caliper slides.

It will also be benifical to remove the pad clips/shims on the caliper bracket. Grind or chisel the rust off the areas under where the pad clips/shims go.....rust build up and you can't get the pad in right and/or they fail to move as needed becuase they are jammed in their too tight.

 

[Xero_Tolerance]

Do you happen to know where they sell that tool you're talking about?

Thanks

 

[DiabloRT]

You should be able to find it at any autoparts store.

Advanced, Auto Zone, Pepboys, may be even Sears

I got mine from Autozone.


Here is an example of the cheap cube one I have
http://www.partsamerica.com/PartDet...de=PBI&MfrPartNumber=648410&CategoryCode=3479


Here is one I would get if I was a professional mechanic and worked on a variety of vehicles Professional

 

[steve]

Hopefully you haven't bent or destroyed the parking brake auto adjuster by trying to force the piston back in rather then screwing it back in.

Steve

 

[AWDPetmitsu]

From your description of how the pads wore, the piston in the caliper is more than likely seized/frozen. It's time for a new caliper. It's best to do them in pairs and change both of the rear ones.