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Discussion Starter #1
I've got a 71 Nova that I upgraded to power brakes using a stock component kit from Pirate Jack. I was happy with the performance until the passenger side front caliper started sticking closed, chewing through brake pads and causing a dangerous pull. I checked all the obvious possibilities like a flexing caliper or a kinked line but didn't find any issues so I assumed it was a bad caliper and had Pirate Jacks replace it. It started working ok and I figured the issue was over but now its started again and I feel bad for guilting PJ to replace the caliper since this isn't the problem.

The caliper seems to only stick when its hot, like hot outside or after its been running a while. Once cooled it will unstick usually. This has to be something to do with the proportioner valve right? I did have to remove a loop where the stock brake line pigtailed to get it to reach the new proportioner but I *think* that was from the back brakes line, honestly can't remember though. Could this be it?

Thanks for any help I just want this gremlin killed.
 

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I had a similar problem, though not as severe as yours, with some rebuilt calipers that I got from O'Reily's. I talked to an old-time brake guy that I know and he told me that when calipers sit on the shelf for too long after being rebuilt the lubricant for the pistons dries out and causes them to stick. After cleaning up the piston bores and installing a rebuild kit (just seals) that only cost a few bucks at NAPA, no more sticking.

Gerry
 

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72, 2 Dr, 383, 700r4
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Same problem here. I installed a new Right Stuff power disk conversion plus all new everything for the entire brake system front and rear including all hard lines too. Got it bled and everything looked good. When installing the tire I went to rotate the passenger front rotor and it was locked hard. Took it all back apart and inspected, reinstalled, same thing. I'm not road ready yet on the build but its hard to push the car. All the other wheels have the proper drag.
 

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Discussion Starter #6 (Edited)
I'm having a hard time believing that the same side caliper would fail twice in a row, but I guess its possible. I'm going to check everything again and maybe replace the hard line. meaning the brake line from the prop valve to the caliper not the banjo nut brake line.
 

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did you maybe let the caliper hang on the rubber line while the install was being assembled ? why i ask i did that once an it made the inner rubber hose collapse where i kinked the hose. it would let brake fluid pressure go to the caliper but wouldn't let the pressure back off. so the brakes stayed tight to the rotor. fix would be a new rubber line.
 

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Make sure the bushings that the caliper bolts go through slide back and forth easy, on one I just did they didn't move, I had to pry them out and lube them to get them to move freely, make sure you use the special caliper grease.
If they don't move easy it will hold the caliper to the rotor, the caliper needs to float back and forth
 

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I would suspect the rubber brake line at the caliper They can look fine on the outside but break down on the inside. I’ve seen gas line do that as well. They fail internally and actually create a one way valve of sorts. Yours appears to be temperature activated.
 

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A friend of mine had an older Suburban in his shop with a similar problem passenger front caliper would stick.. This truck had a notorious ABS system that was known to be problematic and we went through the ABS unit trying to locat the bad solinoid valve and could not locat any problem with the unit.. The problem was at to rubber line to the wheel.. It would pressurize the caliper fine but not allow the fluid to return back to the reservoir.. I’m not sure that you have a valid direct correlation or just a coincidental association with heat in the system.. I would replace the rubber line..
 

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Discussion Starter #11 (Edited)
My system doesn't have rubber brake hoses it has SS metal ones that came with the kit. The type with a banjo nut. Last set of calipers and the new ones I tried lubing the pins with wheel bearing grease and then silver anti seize this did not fix the problem. Replacing the caliper did fix the problem for a few months but now its back. I'm sick of this I think I am just going to start replacing parts until it resolves. Going to start with a new hard line from the prop valve, then a new SS banjo nut line, then a new prop valve.

EDIT: I think before I spend $$ I'm going to swap the SS brake hoses, if the problem moves to the drivers side then the hose is the issue. I don't know what could go bad on a newish SS hose, but the kit was only $500 so they are likely chinesium so I guess anything is possible.
 

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Discussion Starter #12 (Edited)
Make sure the bushings that the caliper bolts go through slide back and forth easy, on one I just did they didn't move, I had to pry them out and lube them to get them to move freely, make sure you use the special caliper grease.
If they don't move easy it will hold the caliper to the rotor, the caliper needs to float back and forth
I've never had this problem before and I guess I didn't know caliper grease is a thing, no vehicle I've ever owned has needed it. Can you recommend a brand and I'll try that when I swap the brake hoses I've used wheel bearing grease and antisieze but maybe caliper grease is the answer.

EDIT: decided to just order Permatex I want to get this sorted this week
 

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Discussion Starter #13
What brand brake pads do y'all use? I've been using Wagner Thermoquiets but since I have to replace pads AGAIN I think I'm going to try something different. The Wagners were pretty tight to get in last time, with the calipers fully expanded I still had to tap them in with a hammer. They broke in and worked fine until the issue reappeared but they are some kind of different looking material then other pads, maybe they make dust thats causing my issue.
 

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My system doesn't have rubber brake hoses it has SS metal ones that came with the kit. The type with a banjo nut. Last set of calipers and the new ones I tried lubing the pins with wheel bearing grease and then silver anti seize this did not fix the problem. Replacing the caliper did fix the problem for a few months but now its back. I'm sick of this I think I am just going to start replacing parts until it resolves. Going to start with a new hard line from the prop valve, then a new SS banjo nut line, then a new prop valve.

EDIT: I think before I spend $$ I'm going to swap the SS brake hoses, if the problem moves to the drivers side then the hose is the issue. I don't know what could go bad on a newish SS hose, but the kit was only $500 so they are likely chinesium so I guess anything is possible.
If you have stainless steel braided lines there is still a liner of rubber or Teflon or something to contain the fluid..
 

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Make sure the bushings that the caliper bolts go through slide back and forth easy, on one I just did they didn't move, I had to pry them out and lube them to get them to move freely, make sure you use the special caliper grease.
If they don't move easy it will hold the caliper to the rotor, the caliper needs to float back and forth
I literally had to press my bushings out. They were frozen by something very gummy. I cleaned them, the rubber ring in the caliper and used some silicone grease. I can now slide them back and forth with my fingers. Reassembled and sure has heck that was the fix. I can now rotate the rotor by hand after applying the brake. These calipers were new too.
 

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Replace the rubber line. I had the same exact problem on my 73 Olds Omega,(Nova platform).Changed the rubber line and problem went away permanently.
 

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Hopefully I can help you a bit, as a 35 year master tech the first thing I would do is diagnose before I replaced another part, my first inclination is that the liner inside your flex line to the caliper is collapsing. The proper way to diag it would be to screw a pressure gauge into the bleeder port and see if the pressure releases after pumping the brake a few times, it should drop as soon as you're off the pedal. I realize not everyone has the kit (stainless steel brakes among others sells them) you could also take it for a ride and get it good and hot and then hop it and crack your bleeder loose, if you get a good shot of fluid then the collapsed hose is your issue. I also rely on my infrared thermometer in these cases, I'll take it for a ride, use the brakes several times and hop out and shoot the temp of the rotors, they should be pretty close to each other. Hope that helps you a bit.
 

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Make sure the bushings that the caliper bolts go through slide back and forth easy, on one I just did they didn't move, I had to pry them out and lube them to get them to move freely, make sure you use the special caliper grease.
If they don't move easy it will hold the caliper to the rotor, the caliper needs to float back and forth

I'm not sure you have this problem fixed :

I'd agree with the "Bad rubber / ss brake hose ......... BUT, more of what Wade says .

The Brake caliper has too MOVE - or - Float back & forth.
go back & check both the 'pins & bushings' . Makes sense that if they can't move / slide back & forth then they may stay rubbing against the rotor/pads.
I've seen 'Bent Pins' before , not letting those bushings slide correctly. (which makes the caliper "stick").

ps..... BRAKE PARTS : buy Raybestos Brake PARTS -- ("the Best In Brakes" ). for over-the-counter brake parts.

just saying , jim
 
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