proportioning valve
Le Mans Master
Joined: Apr 2001
Posts: 6,161
Likes: 0
From: Easton PA
Re: proportioning valve (Ben Taylor)
It is below the brake booster on the driver's side. This usually doesn't go bad, why do you think it needs to be replaced?
Thread Starter
Burning Brakes
Joined: May 1999
Posts: 1,179
Likes: 0
From: waller texas
Cruise-In I Veteran
Re: proportioning valve (82dukman)
i HAVE BEEN HAVING HARD TIME GETTING HARD BRAKE PEDAL AND SOME HAVE TOLD ME THAT PROPORTIONING VALVES CAN BECOME GUNKED UP AND MAYB BE CAUSE THIS PROBLEM. I PERSONNALY DON'T THINK THIS IS MY PROBLEM.I BROUGHT A PRESSURE BLEEDER HOME FROM WORK TODAY AND TRY USING THAT.I DO THINK I AM JUST NOT GETTING ALL THE AIR OUT OF SYSTEM.
Thread Starter
Burning Brakes
Joined: May 1999
Posts: 1,179
Likes: 0
From: waller texas
Cruise-In I Veteran
Re: proportioning valve (82dukman)
NO I HAVEN'T TRIED GRAVITY BLEEDING BUT I HAVE GONE THRU SEVERAL CAN OF FLUID USING CLEAR PLASTIC HOSE INTO CLEAR LITTLE CONTAINER.IT SEEMS I AM GETTING SOLID FLUID WITH NO MORE AIR BUT I STILL DON'T GET A HARD PEDDAL.SOMEONE POSTED ABOUT PRESSURE BLEDDING AND THAT IT WORKED GREAT FOR THEM SO I WILL TRY THAT NEXT.
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Re: proportioning valve (all smiles 81)
I have run into many problems with proportioning valves. When you pressure bleed a system with a buddy do you notice how well the fluid comes out the front bleeders and how sluggish the rear are. On both my vet and mustang I have totally removed the proportioning valves and instantly noticed a big improvement in braking,
I was helping a guy replace his universals on the drive shaft and he couldn't hold the brakes hard enough to keep the wheels from turning while undoing the bolts on the universals. Without the valve it is no problem.
I have big stickly tires on the back and never drive in the rain. Why shouldn't they do there share of braking?
I was helping a guy replace his universals on the drive shaft and he couldn't hold the brakes hard enough to keep the wheels from turning while undoing the bolts on the universals. Without the valve it is no problem.
I have big stickly tires on the back and never drive in the rain. Why shouldn't they do there share of braking?
Advanced
Joined: Apr 2002
Posts: 69
Likes: 0
From: Worcester MA
Re: proportioning valve (all smiles 81)
Have you had any luck yet?? I am having the exact same problem on my 74. I have all new lines, and have just changed the MC. The proportioning valve is going to be next. I also heard that bad piston seals on the calipers and rotor runout can cause air to enter the system??
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Thread Starter
Burning Brakes
Joined: May 1999
Posts: 1,179
Likes: 0
From: waller texas
Cruise-In I Veteran
Re: proportioning valve (schrecke)
I suction bled the brakes and the pedal is alot better but I still don't like the stopping power of brakes.I find it hard to believe the proportioning valve is bad or the booster.I am getting good movement of booster rod so I don't think booster bad either.I think brakes still have some air in system.After suction bleeding the brakes do pull straight now.I did rebuild my right front caliper which had some seepage.
Advanced
Joined: Apr 2002
Posts: 69
Likes: 0
From: Worcester MA
Re: proportioning valve (all smiles 81)
I finally found a solution to my problem. Reposition your front calipers as you bleed them. Where the bleeder valve is with respect to the brake line in, allows for an air bubble to get trapped, and hours (read gallons) of bleeding didn't get it out. I unbolted the caliper and positioned it so the bleeder was as high up as it could be, bled again, and a lot of air come out, flip the caliper back the other way, some more air, flipped it back again, more air. Finally all the air was gone. Good pedal. Great stopping power. In trouble shooting I did change my MC, and my proportioning valve, but the problem still existed after those were changed. I have seen so many similar posts, and I think this may be the answer they're seeking too. Try it out and pass this info around if it works.
