Kind of an emergency. Doing the brake pads and I cant get the rear caliper piston to depress enough to get the new pads in. The fronts were easy enough to push in I just used my hand, but the rears wont move at all. Not even with the use of the "block of wood" technique or a c-clamp. Need the car in the morning. Please give any advice. Thanks.
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Try opening the bleed valve a bit. Or try a quick lite smack around the piston with a ballpin hammer and some penetrating lube spray. Then use the C-clamps again, and turn hard.
When doing my brother's e36 last week, he couldn't get the rear piston back either. I had to put some serious ass behind the c-clamp and it finally went back in. -
Try opening the bleed valve a bit. Or try a quick lite smack around the piston with a ballpin hammer and some penetrating lube spray. Then use the C-clamps again, and turn hard.
When doing my brother's e36 last week, he couldn't get the rear piston back either. I had to put some serious ass behind the c-clamp and it finally went back in.
Ditto
Can also try some channellocks and an old rag and twist it a littleComment
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Just dont score the piston surfaceComment
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I am actually thinking now that the caliper may be seized and that was the problem all along. Here are the symptoms.
The pad on the caliper is considerably more worn that the pad on the other rear caliper, there is a distinct "grinding" type noise coming from that wheel during braking, and like I said before, it is VERY hard to get the piston in, and it still hasnt moved.
Does anyone agree that the caliper is bad? I had a similar problem on a car a few years back, the only difference being the grinding noise could be heard during driving as well as braking.Comment
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a collapsed brake flexy hose will give similar problems. definately open the bleed valve and see if the piston retracts back into the housing.Comment
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Maybe have someone hit your brakes with the caliper off and see if the piston moves?Comment
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Then use the C-clamps again, and turn hard.
I turned hard. Very hard. If it isnt seized, is it possible for me to do more damage to the piston other than scratching it simply by cranking too hard on the c-clamp.Comment
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Maybe have someone hit your brakes with the caliper off and see if the piston moves?
Tried that. It didnt move. Will it move without pads and/or pressure?Comment
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If they were depressed, they should move. Can't tell from your original post if you were able to press the piston in slightly but then it stopped moving - or if you couldn't press it in at all. On mine, I was able to depress them but not enough to get the pads over the rotors. With enough force I was able to finally depress them fully.Comment
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might have to rebuild it, sounds like its frozen. Dealer has rebuild kits.Comment
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it does sound like it might be shot.. but i always depress the piston with a pry bar while its still on the car.
personally, i have no idea why anyone would rebuild these calipers.. rebuilt ones are relatively cheap, and you don;t deal with such a mess.Comment
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it does sound like it might be shot.. but i always depress the piston with a pry bar while its still on the car.
personally, i have no idea why anyone would rebuild these calipers.. rebuilt ones are relatively cheap, and you don;t deal with such a mess.
+1, if you give up on compressing, just get a rebuild unit.Comment
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Most rear brake calipers need to be turned while pushing down. There is a $10 tool for this. If your piston is solid with slots you must push and turn or it will never go in. Not sure if this is the case with the M3.Comment
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Most rear brake calipers need to be turned while pushing down. There is a $10 tool for this. If your piston is solid with slots you must push and turn or it will never go in. Not sure if this is the case with the M3.
Not the case with an M3 and a rebuild is EASY if you have them off the car anyway. $12:clueless:Comment
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