Strange Directional Caliper Rebuild

Sean Marconette · 02-19-2013, 12:31 PM

Does anyone sell a rebuild kit that gets away from the square O-rings for these? Any other recommendations would be helpful. I did a search and read about using scotch brite on the pistons. Someone mentioned a lube as well. Any help or recommendations would be appreciated.

Thanks
Sean

Marco · 02-20-2013, 10:38 AM

I have several sets and rebuild them regularly I take them apart clean them well with brake clean, I use steel wool to clean the pistons and the cylinders, the square O rings are all I am aware of and you want to reassemble with sil glide they sell it a NAPA

69Cobra · 02-20-2013, 12:04 PM

What's the reason for the rebuild? Do they start sticking or leaking? I've put them on my car about 8 years ago and haven't touched them.

Sean Marconette · 02-20-2013, 01:35 PM

Thanks Marco,

I have not had any problems with them. Just trying to free up the brakes. I have installed springs in-between the pads to help reduce drag. Its my understanding that on Wilwood calipers that others have replaced the square O-rings with a traditional one and that helps the piston retract. I have had these for 7 years or so. I have seen other stockers with the wheels off the ground and the wind alone rotates the front wheels. Mine takes effort to move them.

Thanks for the help.

Sean

Tom Goldman · 02-20-2013, 02:02 PM

The idea behind a square o-ring is that it will rock slightly when pressure is applied and rock back when released , thereby slightly retracting the piston.
If you are experiancing excessive drag ,I'd be looking at caliper squareness, or excessive residual pressure caused by the brake pedal /master cyl clearance or the master cyl itself.
Calipers not being parallel to the rotor is a common problem ,especially on rear housings.
Even when using a good narrowing fixture ,I've seen housing ends measure .015-.020" out of square at the housing which is .060" or more at the end of the rotor.

Sean Marconette · 02-20-2013, 08:08 PM

Tom,
I will re-evaluate how square I have the calipers. I have removed the factory proportioning valve and installed an aftermarket one. I have new flex brake lines.

Thank You
Sean

02-19-2013, 12:31 PM	#1
Sean Marconette Senior Member Join Date: Mar 2006 Posts: 977 Likes: 794 Liked 275 Times in 76 Posts	Strange Directional Caliper Rebuild Does anyone sell a rebuild kit that gets away from the square O-rings for these? Any other recommendations would be helpful. I did a search and read about using scotch brite on the pistons. Someone mentioned a lube as well. Any help or recommendations would be appreciated. Thanks Sean __________________ Sean Marconette 84 Mustang 5060 SS/N

02-20-2013, 10:38 AM	#2
Marco Junior Member Join Date: Oct 2005 Location: Florida Posts: 73 Likes: 0 Liked 4 Times in 1 Post	Re: Strange Directional Caliper Rebuild I have several sets and rebuild them regularly I take them apart clean them well with brake clean, I use steel wool to clean the pistons and the cylinders, the square O rings are all I am aware of and you want to reassemble with sil glide they sell it a NAPA

02-20-2013, 12:04 PM	#3
69Cobra Senior Member Join Date: Aug 2007 Location: California, Ky Posts: 669 Likes: 61 Liked 2 Times in 2 Posts	Re: Strange Directional Caliper Rebuild What's the reason for the rebuild? Do they start sticking or leaking? I've put them on my car about 8 years ago and haven't touched them. __________________ Kris Rachford 69 Cobra 428CJ 4 Speed C/S 3032

02-20-2013, 01:35 PM	#4
Sean Marconette Senior Member Join Date: Mar 2006 Posts: 977 Likes: 794 Liked 275 Times in 76 Posts	Re: Strange Directional Caliper Rebuild Thanks Marco, I have not had any problems with them. Just trying to free up the brakes. I have installed springs in-between the pads to help reduce drag. Its my understanding that on Wilwood calipers that others have replaced the square O-rings with a traditional one and that helps the piston retract. I have had these for 7 years or so. I have seen other stockers with the wheels off the ground and the wind alone rotates the front wheels. Mine takes effort to move them. Thanks for the help. Sean __________________ Sean Marconette 84 Mustang 5060 SS/N

02-20-2013, 02:02 PM	#5
Tom Goldman VIP Member Join Date: Jan 2003 Location: Allentown,PA Posts: 2,475 Likes: 887 Liked 865 Times in 235 Posts	Re: Strange Directional Caliper Rebuild The idea behind a square o-ring is that it will rock slightly when pressure is applied and rock back when released , thereby slightly retracting the piston. If you are experiancing excessive drag ,I'd be looking at caliper squareness, or excessive residual pressure caused by the brake pedal /master cyl clearance or the master cyl itself. Calipers not being parallel to the rotor is a common problem ,especially on rear housings. Even when using a good narrowing fixture ,I've seen housing ends measure .015-.020" out of square at the housing which is .060" or more at the end of the rotor. __________________ Tom Goldman 1500 SG , 1506 STK

02-20-2013, 08:08 PM	#6
Sean Marconette Senior Member Join Date: Mar 2006 Posts: 977 Likes: 794 Liked 275 Times in 76 Posts	Re: Strange Directional Caliper Rebuild Tom, I will re-evaluate how square I have the calipers. I have removed the factory proportioning valve and installed an aftermarket one. I have new flex brake lines. Thank You Sean __________________ Sean Marconette 84 Mustang 5060 SS/N Last edited by Sean Marconette; 02-20-2013 at 08:47 PM. Reason: Corrected original statement