Proportioning Valve in or out????

[rooster57]

Saturday i pulled off the road in a gravel parking lot and front brakes slid and no rear. I had the valve out about 7 to 10 turns going to the rear brakes. What is a good starting point on the valve setting guys. I was under the impression as i pump the pedal the rear linings would adjust into position. What do ya think??????

 

[EX JUNK]

Perhaps this link will help you Rooster.

Install a Brake Proportioning Valve - Tech Article - Chevy High Performance Magazine

Jim

 

[putz]

Rear lining do not adjust by pumping brakes they are supposed to adjust when you back up and hit brakes. Supposed to the operative words best bet adjust till they just drag on the drums then hit the brakes then check the adjustment one more time. Because hitting the brakes centers the shoes in the drum.

 

[Ted Brown]

I could be wrong, but I was always under the impression that the pro valve was used to adjust for lock up (emergancy) stops only, should not have an effect on normal stopping... YES?

 

[Wild Mango]

The prop valve limits pressure to the rear brakes.
In a max braking effort situation the rears should not lock before the fronts, transfer means that the front end "weighs" a fair bit more than the rear and can take a lot more brake effort before lock up- the fronts usually do a lot more braking work than the rears. Transfer means you can't set the bias up on a brake machine, you have to do it "on the road".
Discs require a lot more line pressure than drums, which have a built in "power assist" characteristic.
Both these mean the rear brake circuit will need less hydraulic pressure than the front, especially if you have drums on the rear. The prop valve will do this for you.
Properly adjusted, the rears will lock up just after the fronts, and if you set them up like this, the balance will generally be correct for most braking situations.
Setting the brake bias is always fun because it involves the Burning of Rubber, a rodders ritual of devotion!

 

[rooster57]

I know when i set them up and pumped the brakes i could hear the adjust lever turning the star adjuster for the brake linings.. I dont see how backing up would have anything to do with it . I have heared that for years and doesnt make any sence to me . But you know how small chickens brains are !!!

 

[putz]

Backing up if brakes are out of adjustment rocks the shoes against the top anchor pin and supposed to adjust until the shoes and adjuster don't rock in the drum.

 

[Ted Brown]

That's correct, if your self adjusting brakes need adjustment, back up and stop hard, a few times, and it tightens the shoes a bit each time... Brakes are fun and funny.. PS, I don't think I would even want anything in the brake lines that cut DOWN pressure to anything, better to change something else... if really needed to have less stopping power.. as most cars need more, not less, I find...

 

[oldtman]

more brake info. the self energizing drum brakes have a different curve when you plot stopping force vs pedal pressure. disc brakes are more of a straight line. you have to balance the brakes for your chassis wheel -tire sizes, etc. a 2 master cyl with a balance bar gives the most adjustment...there were picts posted a week or so here.

 

[oldtman]

backing up tightens the self adjusting cable properly adjusted, the cable does not move enough to click the adjuster .... when the shoes are loose the cable moves farther and the spring pulls the pawl and can click the adjuster.

 

[rooster57]

mine has no cable when you apply the brakes the lever attached to the rear lining moves with the lining and rotates the star adjuster and keeps the shoe in contact with the drum as the shoe wears.

 

[bucketkids]

Hey Jim, That is the second time you posted that article and the 10th time I read it. Thanks again, I seem to get something more from it and it was a great refresher. I am getting ready to run my brake lines now that I mounted RPM's Master cylinder.

Does anyone have a grocery list for the parts store on fittings, hose etc... I have read many forums and feel confident this will go well but with gas prices I know I will make atleast 20 trips before I actually remember everything.

Also,,, 1/4 inch or 3/16???

What a great day that was!

 

[EX JUNK]

Hey Jim, That is the second time you posted that article and the 10th time I read it. Thanks again, I seem to get something more from it and it was a great refresher. I am getting ready to run my brake lines now that I mounted RPM's Master cylinder.

Does anyone have a grocery list for the parts store on fittings, hose etc... I have read many forums and feel confident this will go well but with gas prices I know I will make atleast 20 trips before I actually remember everything.

Also,,, 1/4 inch or 3/16???

What a great day that was!

To answer one question, use 3/16". As for what all you will need to do the job, I suggest that you and your son come to my place and I'll have the car up on jack stands and you can make a drawing and note all the fittings that you'll need. I'll give you a good source to buy all that you need. When you finish, I'll take your son for another ride. Deal?

Jim

 

[bucketkids]

To answer one question, use 3/16". As for what all you will need to do the job, I suggest that you and your son come to my place and I'll have the car up on jack stands and you can make a drawing and note all the fittings that you'll need. I'll give you a good source to buy all that you need. When you finish, I'll take your son for another ride. Deal?

Jim

That is Hilariouse Jim, I told little V the other day it was time to pay you another visit as the project is moving forward. The very FIRST thing he asked is if I thought you would take him for a ride!!! I plan to catch up with you Next weekend at the Turkey run and then with in the next couple weeks I would love to take you up on your generouse offer. THX