I need a brake

[Old Iron]

Solved my brake dilemma

OK, I've never had a problem with brakes, until now [S
I put the entire front end out of a 73 1/2 ton with disc brakes, on the front of my 66 C10 along with a rebuilt Wagner dual reservoir master cylinder, rebuilt calipers, all new steel lines and new rubber brake lines.
I bled the system by gravity feed then a two person pump and bleed then a vacuum pump. No air coming out of the bleeders just fluid.
Still I have a soft pedal goes half way down before I get any kind of pedal too.
I did not use a proportioning valve this round. Does a proportioning valve hold any kind of residual pressure to the brakes at all
Or does it just regulate pressure to the rear so they don't slide the rear tires ?
Things I've done:
Got another master cylinder to see if that could be it and it made no difference
Checked the size of the master cylinder, it's a 1-1/8" bore.
Help

 

[DoubleJ]

Prop valves don't work as a residual valve, residuals are in the m/cyl. Think maybe you have a problem with the rears? I assuming you still have drums on the back...may need adjusting if you still have drums on the rear. Everything else sounds okay but the 73 setup did use a combo valve (prop and metering) Should still be able to get a pedal without it.

 

[Old Iron]

Prop valves don't work as a residual valve, residuals are in the m/cyl. Think maybe you have a problem with the rears? I assuming you still have drums on the back...may need adjusting if you still have drums on the rear. Everything else sounds okay but the 73 setup did use a combo valve (prop and metering) Should still be able to get a pedal without it.

Still have rear drums.
Forgot to mention that I adjusted them up some, to the point they drug a little.
I didn't think the prop valve had any residual to them. Thanks

 

[DoubleJ]

You don't have too much free play from the pushrod into the m/cyl do you? I have run across that before causing the same kind of problem you have. Otherwise I'd try the other master. Hope this helps!

 

[izzy]

brakes

did you bench bleed the new master cylinder?

 

[rainman]

You didn't mention whether you used residual valves or not!! If you're m/c is mounted in a fairly low location, you'll need them!!

 

[Old Iron]

You don't have too much free play from the pushrod into the m/cyl do you? I have run across that before causing the same kind of problem you have. Otherwise I'd try the other master. Hope this helps!

All I done was adjust the rod where the pivot bolt went in the pedal arm without pushing the rod any.
I already changed the mst and it made no difference.
I installed a rebuilt booster and changed the rod from a manual brake to a power brake rod.
Thanks

 

[Old Iron]

did you bench bleed the new master cylinder?

Yep just like they said to and got all air out.
Thanks

 

[Old Iron]

You didn't mention whether you used residual valves or not!! If you're m/c is mounted in a fairly low location, you'll need them!!

No residual valves. The master is located on the firewall, in the factory position.
Thanks
I know I'm missing something just don't know what

 

[Old Iron]

Solved my brake dilemma

Got to thinkin, which hurt.
I remember seeing a brake pedal arm that had two holes in it, one was for a manual brake system for more leverage and the other was for a power brake system which needs less pressure on the pedal
So I drilled another hole 3/4" lower in the pedal arm and now I have full pedal and great brakes
Thanks to all that helped, I appreciate it [cl

 

[Blue Eyed Devil]

Glad you got it figured out! Good binders come in handy sometimes.

 

[Old Iron]

Me too, it was drivin me crazy

 

[rainman]

Good deal, also glad you figured it out!![cl

 

[DoubleJ]

Glad to hear you got!