Brakes sticking a lil do I have right prop. valve and adj. on brake rod?

[oldblue1968chevy]

If im at a drive thru or someplace on a slight hill I can be in N and the truck doesnt roll w/o putting in gear and giving some gas. Its a 3 spd. manual. It just goes' errrghhhh' (brakes just barely holding it back).

New Calipers rotors (now have slight groove). Pads Soft lines f/r ALMOST new hardlines (except here and there). New MC booster. Prop. valve is idk how old.

Here is a pic of rod/firewall. It doesnt seem to adj. any more than this.

Someone on here told me to check my caliper bolt bushings or something.

Also, My front wheels are covered in brake dust after a few days. I mean dirty. This doesnt seem normal. Thankyou.

[DKN]

Check to see if the master cylinder is "preoaded". When the brake feels stuck, loosen the 2 bolts that hold the master cylinder to the booster. Move the master cylinder away from the booster. See if the brake stil feels stuck. If it becomes free then you have the master cylinder preloaded and need to adjust the booster rod, or brake pedal rod.

If it still feels stuck open the bleed screws for a moment. If it becomes free you have have an obstruction somwehere in the brake lines, or valve. You will need to replace the blocked line or valve.

Danny Nix
CPP

[oldblue1968chevy]

smart man!! Will try, tomorow after church or something. Thanks!

[cdowns]

that appears to b a distribution block from a drum system not a proportiong valve setup for a disc/drum system the residual valves will cause the discs to drag

[michael bustamante]

Originally Posted by cdowns

that appears to b a distribution block from a drum system not a proportiong valve setup for a disc/drum system the residual valves will cause the discs to drag

it looks like a disc drum set up prop valve to me, but I dont see the little bleed valve you push in to bleed the system. I dont mean to correct you cdowns but I just swapped to disc earler this month and that was one of my issues as well, this is not from a drum drum setup.
I say double check the calipers, theyre cheap to replace if theyre sticking and also makes sure the caliper pin bushings are not binding the bolt. also make sure you properly bench bleed the mater cyl.
looking at the pic again you CAN see the plunger thing, its the same shade as the exhaust manifold and hard to see but it is there!, Now I say re-bleed the whole system and do a search on how to bleed using that plunger in the prop valve as I havent learned how yet

[oldblue1968chevy]

really?!?! I coulda swore i swapped em!! Can you get em at parts store?

[cdowns]

from the pic it looks to me that valve doesnt have the centering pin that the prop valve type has// it would b in the foward part of the valve with a rubber type boot on it

[raycow]

Isn't the centering pin what operates the switch?

Ray

[cdowns]

theres a switch on the distribution block but not the resting pin like the propvalve /combonation valve has// there are illustrations in the service manuals that can show better than i splain// i just know to look for the rubber bulby thingey

[oldblue1968chevy]

So....................I have the wrong prop. valve (I need one fr 71-72 1/2 ton 2wd
)?

thanks!

[oldblue1968chevy]

On the very front it does indeed have a lil rubber button.

1-Do I have the right...valve, prop. valve, splitting valve, whatever?

2-If yes, how do I bleed my brakes (something about the button, lol)?

[lolife99]

I agree,... that looks like a drum brake distribution block.
You need a disc brake porportioning valve.
Many board vendors or online companies sell them.

[oldblue1968chevy]

Can someone show me what they look like (post a pic)

would one from a 73-87 work? Thanks

[lolife99]

This is an aftermarket porportioning valve that I got from www.performanceonline.com that I put on my '69.

You can make a 73-87 porportioning valve work,... but the lines and port locations are slightly different.
(they have two "exit" ports for the front brake lines, instead of one, like the 71-72 style have)

[oldblue1968chevy]

pics of stock prop. valves? do these ever go bad? because im thinkin bout a junkyard one?

[oldblue1968chevy]

Ok guys, I started lookin' at old pictures and instead of using the disc brake one I think I just put mine on backwards lol.

soooo, wheres a good place to order from im lookin' for a used one too but may as well get a new'un.. lol I feel dumb, heres a link to my build thread of the pics..

67-72chevytrucks.com/vboard/showthread.php?p=4075826#post4075826

[lolife99]

Originally Posted by oldblue1968chevy

Ok guys, I started lookin' at old pictures and instead of using the disc brake one I think I just put mine on backwards lol.

soooo, wheres a good place to order from im lookin' for a used one too but may as well get a new'un.. lol I feel dumb, heres a link to my build thread of the pics..

67-72chevytrucks.com/vboard/showthread.php?p=4075826#post4075826

You need to trace the lines down and see where they go.
I'm not sure it's on backwards.

[lolife99]

http://www.performanceonline.com/GM-...-VALVES-PV672/

Just make sure you get the one for 2 wheel disc, (or disc/drum),... NOT 4 wheel disc.

[oldblue1968chevy]

Thanks lowlife! Your just a suspension guru eh? So you guys see what im talkin bout (its upside down) and your positive im right?(and that your right too)

what'll it hurt keep drivin it like this (till i get my part)

[lolife99]

The rear outlet of the porportioning valve goes to the rear brakes.
Check that out first.
The front bowl of the M/C is usually the front brake bowl.
(Usually bigger for the front disc brakes,... but not always. Depends on the brand and style of master cylinder)
The valve I posted has an extra front port that will have to be plugged.
(see the top front plug in th pic I posted)
73-87 trucks had two individual lines going to each front brake.
The 67-72 truck have one line that goes down to the frame and then tees off to the front left and right brake.

[oldblue1968chevy]

The line comming off the back of the valve goes to the rear brakes. (just 1 line, pretty big)

line comming off the front bottom goes to the T and goes out to each front wheel.

2 lines on the top with a wire in the middle (I assume brakefluid level switch or something). front top line goes to front bowl on the MC and rear top line goes to rear bowl on MC (MC is from autozone or oreilly or somewhere).

[lolife99]

Did all this start after the wreck?

[oldblue1968chevy]

No ever since I went to discs. But good thinking.

[lolife99]

Also,... where did you get your m/c and porportioning valve?

[Shane]

should be two different size fittings that would prevent "putting it on backwards" ...