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  • SN95 4.6L Mustang Tech

caliper piston won't turn in!

  • Thread starter Thread starter the98stang
  • Start date Start date Sep 22, 2006

the98stang

Active Member
Aug 12, 2005
2,408
0
47
Clovis, CA
Sep 22, 2006
#1
  • Sep 22, 2006
  • #1
So my damn caliper piston (rear passenger side) will NOT move in. I am using a brake tool to turn it clockwise. Are you suppose to turn it conter-clockwise on the passenger side or something? The master cylinder is half full and the cap is off. So why the f-ck won't it turn in?! Please help me guys. I need my car back. Thanks...

Tanner
 

bads

New Member
Aug 29, 2004
15
0
0
Merrillville, IN
Sep 22, 2006
#2
  • Sep 22, 2006
  • #2
I honestly just finished my brakes 25 minutes ago. Both sides turn in the same way, clockwise. I usually losen the bleeder up at the caliper when i turn the piston in, makes it a little easier since you have to (should) bleed them anyways.
 

merc123

Active Member
Jan 27, 2003
420
2
39
North GA
Sep 23, 2006
#3
  • Sep 23, 2006
  • #3
+1 on the open the bleeder a little to let the pressure off the piston.
 

the98stang

Active Member
Aug 12, 2005
2,408
0
47
Clovis, CA
Sep 23, 2006
#4
  • Sep 23, 2006
  • #4
I already bled the brakes. Why would one piston go in, but not the other? So you guys think there's too much pressure on the passenger side? Should I just open the valve again?
 

merc123

Active Member
Jan 27, 2003
420
2
39
North GA
Sep 23, 2006
#5
  • Sep 23, 2006
  • #5
No, don't open the bleedder...

bads said:
I honestly just finished my brakes 25 minutes ago. Both sides turn in the same way, clockwise. I usually losen the bleeder up at the caliper when i turn the piston in, makes it a little easier since you have to (should) bleed them anyways.
Click to expand...

merc123 said:
+1 on the open the bleeder a little to let the pressure off the piston.
Click to expand...
 

BennyBlown2v

New Member
Dec 9, 2004
1,233
1
0
Carmel, INdiana
Sep 23, 2006
#6
  • Sep 23, 2006
  • #6
open teh bleeder on the bastard caliper!!
 

the98stang

Active Member
Aug 12, 2005
2,408
0
47
Clovis, CA
Sep 23, 2006
#7
  • Sep 23, 2006
  • #7
once I open that bleeder valve a little will I have to bleed the entire system again? Or that caliper only? Or not at all?
 

BennyBlown2v

New Member
Dec 9, 2004
1,233
1
0
Carmel, INdiana
Sep 23, 2006
#8
  • Sep 23, 2006
  • #8
Just that caliper, or not at all.
 

the98stang

Active Member
Aug 12, 2005
2,408
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Clovis, CA
Sep 23, 2006
#9
  • Sep 23, 2006
  • #9
BennyBlown2v said:
Just that caliper, or not at all.
Click to expand...

Ok I finally got the bastard in! I guess loosening the valve let off some pressure in the lines. But I have a few more questions..

What are those tabs in the middle of each rear brake pad? Is the caliper suppose to push down on them or something? My haynes book doesn't say anything about it.

Also, I noticed the front brake pads rub against the rotor when I turn the wheel. But the wheel isnt bolted down all the way yet because thje car is still on jack stands. So I assume this is normal because the rotor can't be seated fully until the wheel is bolted all the way to push against the rotor hat

And lastly, the pads are suppose to be pushed up against the rotor fully, right? I Just don't understand how that works because if the car is moving, that means the pads will constantly rub against the rotors. Unless they "float" between the calipers

Sorry for all the n00b sh1t guys. This is my first time doing brakes! Guess theres a first time for everything! Thanks again!

Tanner
 

drag0nfan's04GT

New Member
Sep 9, 2005
58
0
0
Sierra Vista, AZ
Sep 23, 2006
#10
  • Sep 23, 2006
  • #10
I just did my brakes a couple of days ago, and I loosened the bleeder on that same caliper. I've done a lot of brakes, but not on any newer vehicles. I didn't know that the caliper piston turned vs just pushing it in with a C-clamp. I knew it looked different than others I'd worked on. I tried like hell to get that damn thing to move. I was at the auto shop on post here and the on-duty mechanic saw I was getting pissed and got me the right tool. It was easy then. The only problem I ran in to was that the round thing with two prongs that goes against the caliper piston...well, one of the prongs was broken off. I eventually got it though. I just needd to add some fluid after that.
 

the98stang

Active Member
Aug 12, 2005
2,408
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47
Clovis, CA
Sep 23, 2006
#11
  • Sep 23, 2006
  • #11
drag0nfan's04GT said:
I just did my brakes a couple of days ago, and I loosened the bleeder on that same caliper. I've done a lot of brakes, but not on any newer vehicles. I didn't know that the caliper piston turned vs just pushing it in with a C-clamp. I knew it looked different than others I'd worked on. I tried like hell to get that damn thing to move. I was at the auto shop on post here and the on-duty mechanic saw I was getting pissed and got me the right tool. It was easy then. The only problem I ran in to was that the round thing with two prongs that goes against the caliper piston...well, one of the prongs was broken off. I eventually got it though. I just needd to add some fluid after that.
Click to expand...

Are you talking about those two prongs in the center of the brake pad? Is the piston suppose to push down on them or something?
 
B

bdcardinal

tree hugger
Jun 10, 2003
3,612
16
69
santa barbara, CA
Sep 23, 2006
#12
  • Sep 23, 2006
  • #12
the 2 dots on the piston should be straight up and down.

its normal to have some drag when you first install the pads and spin evrything. when the wheels are torqued, everything will even out.
 

Brute03

Member
Mar 20, 2006
232
0
16
Sep 23, 2006
#13
  • Sep 23, 2006
  • #13
yea those raised dots on the pad should go into the slots on the piston
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,236
17,921
224
Massachusetts
Sep 23, 2006
#14
  • Sep 23, 2006
  • #14
the98stang said:
What are those tabs in the middle of each rear brake pad? Is the caliper suppose to push down on them or something? My haynes book doesn't say anything about it.

Also, I noticed the front brake pads rub against the rotor when I turn the wheel. But the wheel isnt bolted down all the way yet because thje car is still on jack stands. So I assume this is normal because the rotor can't be seated fully until the wheel is bolted all the way to push against the rotor hat

And lastly, the pads are suppose to be pushed up against the rotor fully, right? I Just don't understand how that works because if the car is moving, that means the pads will constantly rub against the rotors. Unless they "float" between the calipers
Click to expand...

Thge tabs on the pad fit into the slots on the piston that you used to turn the piston around. That's why you need to make sure the piston is turned so ther slots are at 12 and 6 o'clock and then test the pad to make sure the slots fit inside the slots.

The pads rubbing on the rotor is normal. During normal driving, there is some slight rotor wobble that spreads the pads out and pushes the piston in minimizing friction. If you ever jack up your front wheel after driving, you'll notice the wheel turns with little or no drag of the pads.

These calipers are the "floating" caliper type, so they will always self-center and adjust. You just need to make sure the slide pins are properly lubed.
 

the98stang

Active Member
Aug 12, 2005
2,408
0
47
Clovis, CA
Sep 23, 2006
#15
  • Sep 23, 2006
  • #15
damn...I just put the entire thing together, and I don't know if the piston notches are at 12 and 6 o'clock . I drove the car about a mile too, just to "bed" them. Do you think the rear pads/calipers are ruined now?

So the metal "prongs" from the pad fit into the notches on the piston?
 

oxfordgt

Member
Apr 30, 2006
288
2
18
Clarksville, TN
Sep 25, 2006
#16
  • Sep 25, 2006
  • #16
I just did my buddys brakes the other day and had the same problem. He let his pads wear down to much and the rear passenger piston came out to far. We had to remove the caliper so we could put enough pressure on it while turning it to get it to go back into place.
 

Mike97gt

it doe snot
Founding Member
Jan 26, 1999
10,633
7
89
the people's republic of massachusetts
Sep 25, 2006
#17
  • Sep 25, 2006
  • #17
the98stang said:
Ok I finally got the bastard in! I guess loosening the valve let off some pressure in the lines. But I have a few more questions..

What are those tabs in the middle of each rear brake pad? Is the caliper suppose to push down on them or something? My haynes book doesn't say anything about it.

Also, I noticed the front brake pads rub against the rotor when I turn the wheel. But the wheel isnt bolted down all the way yet because thje car is still on jack stands. So I assume this is normal because the rotor can't be seated fully until the wheel is bolted all the way to push against the rotor hat

And lastly, the pads are suppose to be pushed up against the rotor fully, right? I Just don't understand how that works because if the car is moving, that means the pads will constantly rub against the rotors. Unless they "float" between the calipers

Sorry for all the n00b sh1t guys. This is my first time doing brakes! Guess theres a first time for everything! Thanks again!

Tanner
Click to expand...

the tabs in the middle of the pads line up with the grove in the caliper piston.this is why you have to have the groove on the piston face right in the center or the caliper wont want to go back on. One last thing make sure the spings at the top of the pad stay in plce under the caliper, sometimes one of them will pop out
 

the98stang

Active Member
Aug 12, 2005
2,408
0
47
Clovis, CA
Sep 25, 2006
#18
  • Sep 25, 2006
  • #18
OK guys I got everything all situated . The piston notches are at 90 degrees with the caliper, and the prongs are in place.
 
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