Charger proportional valve

[charger freak2]

REWARD!!!!!!!!

I can't seem to get the brakes to work, I changed the master cylinder, calipers, all lines, bled everything, blocked off front brake lines and can get back brakes on both sides of master cylinder. eliminated proportional valve and can't get a pedal.this prop. valve is not original but looks ok, does anyone know how to adjust?

[Nacho-RT74]

welcome.
first we need to know year.
second what exactly is the fail. What do you feeel when try to break ( beside get scared LOL )

[charger freak2]

1973 charger, can't get front brakes, does the proportional valve keep some pressure at the front disks so it wouldn't take as much pressure to stop?

[The70RT]

If you have pressure on both sides when you open the bleeders on the calipers with no brakes applied, I would say the valve is sticking. That would lead to more pressure to the back thus making your rears lock up and the front sticking from what pressure you do get to them and not allowing the pressure to release.

[John_Kunkel]

If there is pressure at the front brakes with the pedal released the most likely cause is a misadjusted master cylinder pushrod.

If the pushrod is adjusted too ong (either power or manual) it will prevent the rear piston in the MC from fully returning when the pedal is released, if the rear piston doesn't return it will block the compensating port and trap the fluid pressure in the front brakes because the fluid can't return to the reservoir.

[charger freak2]

If I take the master cylinder off , does the pushrod turn to adjust in & out? or do I have to get a longer one?

[charger freak2]

No, What I meant is that with all lines to front and back brakes connected and bled, the pedal goes to the floor, if i connect the back brakes only, with the other side of the master cylinder plugged, i have excellent back brakes, when i connect the front brakes and plug the rear, i still dont have front brakes just a mushy pedal, I get some pressure at the front, not much.

[Nacho-RT74]

Did you check if brake fluid level is changing at master cilinder bowls ?

Do you get brakes warning light on when pump at soft pedal moment ?

Pump, pump, pump, pump, pum untill you get LOT tired and then remove master cilinder cap. Get ready water to wash the brake fluid if fluids just came out at cap release moment.

If so, then sounds to me like a damaged dist block. Brake fluid could it be returning throught block and lines up to master cilinder again. Broken O rings inside. They are starting to get damaged NOW. Lucky they are available NOW, same as originals.

[charger freak2]

I by-passed the proportional valve and just ran the lines straight to the calipers and still get no pedal, thats why I thought maybe that prop. valve had a check valve in it to maybe keep some of the pressure in the caliper so when you hit the brake it doesn't take as much fluid to stop the car? I have been messing around with these brakes for over 2 months ( no lie) and the car needs so much more and I can barely move it around.

[Nacho-RT74]

that prop valve is original. For the bracket I'd say is 72 but works the same... dunno why you said on first post is not.

I think I can't help that much on something is too easy and obvious... just a fluid throght lines to push pads.

Unless the problem is inside booster

[charger freak2]

changed master cylinders before, never had this.

[The70RT]

changed master cylinders before, never had this.

Maybe they gave you the wrong master cylinder then Did you measure and see if they were the same where it connects to your rod?

[John_Kunkel]

No, What I meant is that with all lines to front and back brakes connected and bled, the pedal goes to the floor, if i connect the back brakes only, with the other side of the master cylinder plugged, i have excellent back brakes, when i connect the front brakes and plug the rear, i still dont have front brakes just a mushy pedal, I get some pressure at the front, not much.

You have a faulty master cylinder, it's bypassing internally.

[Nacho-RT74]

No, What I meant is that with all lines to front and back brakes connected and bled, the pedal goes to the floor, if i connect the back brakes only, with the other side of the master cylinder plugged, i have excellent back brakes, when i connect the front brakes and plug the rear, i still dont have front brakes just a mushy pedal, I get some pressure at the front, not much.

You have a faulty master cylinder, it's bypassing internally.

that's my same opinion

[charger freak2]

I thought it maybe was a bad master cyl. the first time, I'm on my 3rd one, took a whole day almost to bench bleed it, I didn't think to measure the distance of the rod, compared to the cylinder---------Thanks

[The70RT]

I thought it maybe was a bad master cyl. the first time, I'm on my 3rd one, took a whole day almost to bench bleed it, I didn't think to measure the distance of the rod, compared to the cylinder---------Thanks

Hopefully you have the original still and didn't turn it in for a core. They may have gave you the wrong one more that once.

[charger freak2]

Big time rookie mistake------------- I put the front calipers on the wrong sides of the car, the bleeders were not at the top, allowing air to be trapped.

[The70RT]

 

[Charger1973]

Good to hear you got it figured out anyway.  Got anymore pics of that car?  What size rear wheels are those? 

[Nacho-RT74]

Big time rookie mistake------------- I put the front calipers on the wrong sides of the car, the bleeders were not at the top, allowing air to be trapped.

then yourself won the REWARD!!!!

GOOD TO KNOW YOU FIGURED OUT!!!