brakes

will34

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Jun 16, 2019
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I have a problem with my front disc brakes. When I press and release my pedal. The front bakes remain on. All new pads, rotors, calibers, master cylinder and boaster. Only thing old is proportioning valve. Is it possible to run brake line from master to front and by pass valve.

mike
 
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74stang2togo

NERD!
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I have a problem with my front disc brakes. When I press and release my pedal. The front bakes remain on. All new pads, rotors, calibers, master cylinder and boaster. Only thing old is proportioning valve. Is it possible to run brake line from master to front and by pass valve.

mike
Short answer, no.

Long answer, you need your proportioning valve to meter pressure in the system between the axles, otherwise the rear brakes lock up first and you spin out.

That said, you didn't list brake hoses among the things you've changed, and your symptoms describe an internal failure of the rubber hoses perfectly.
 

will34

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Jun 16, 2019
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ontario
Yes all steel brake lines and flex lines are new. There are 2 lines from master to the proportioning valve. From valve there are 2 lines to front and 1 to the back. Can I put a tee in the line from master to the valve for front brakes. Then feed the front from the tee. Then cap off the 2 lines from the valve to the front. If this is not possible. Where can I buy a new proportioning valve.
mike
 

LILCBRA

I started this morning by knocking out some studs
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If I'm understanding your second post correctly, you're still asking if you can bypass the proportioning valve. It is NOT advised.


If you're not able to locate a stock unit, you could go with an adjustable unit. Those are sold through most any parts source - Summit, Jegs, CJ Pony Parts, etc.

As for your calipers not releasing the rotor when you let off the pedal, you could have faulty calipers. Are they actually NEW units or are they refurbished? Are the sliding components of the calipers clean and not pitted? I guess what I'm getting at is I really don't think the proportioning valve is the problem at all, it sounds like there is a problem elsewhere in the system.
 
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jozsefsz

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Agree with LILCBRA, I'm going to guess (with the assumption new calipers aren't seized) that it's a mis-adjusted pushrod behind the master cylinder. If it's adjusted too long (the end of it threads in & out) your brakes will never release.

You can test this easily without disassembling anything. Press the brake, get the front brakes to lock as they do now, and then loosen the bolts holding the master cylinder to the booster. If the brakes release, there's your problem.
 

78mIIman

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Dec 19, 2016
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Had that happen with mine too when put a new master in. Didnt adjust the pushrod correctly, and everytime i'd brake, front wheels would stick. Adjusted the pushrod, and had no problem since. I'd say, check pushrod first, then check proportioning valve. If all that checks out, see if those new calipers are sticking.
 
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