Brake issues

[Classicman]

Anyone knows how to fix front brakes? I have chevy super cheyenne 1972 BB 402 . I replaced front brakes, rotor, calipers, and brake pads. I still have problems when I stop, I have to take my distance to stop my truck . Rear brakes (drums) works better than front . Any suggestion how to fix the issue. . Thanks.

[Classicman]

I forgot to write that I did all the process like bleeding etc etc and I still have the problem ..
Thanks.

[dwcsr]

Originally Posted by Classicman

I forgot to write that I did all the process like bleeding etc etc and I still have the problem ..
Thanks.

I had a similar issue and the P valve was not being centered when I bled the brakes and its now shifted forward shutting off the front. There is a tool to keep it centered when you bleed the brakes. If you can't find the tool PM me.

[Keith Seymore]

Need a bit more detail; what do you mean when you say "I have to take my distance to stop my truck ". Meaning you have to allow for a lot of stopping distance?

If the "rears work better than the fronts" based on the hardware you've replaced I would suspect a pressure issue of some kind in the front. Either as a result of an improper/incorrectly functioning proportioning valve or collapsed/clogged front brake hoses.

I would ask you to figure out a way to measure brake line pressures and get back with us.

K

[jhwkns]

It could only be one of four things. M/C, booster, proportioning valve or brake lines. From you description, I'd be suspect of the prop. valve.

[Stickman]

Like jhawkins said, I'm going with P/valve or booster. Not too long ago I had the same thing happen and replaced PPV and booster with autozone or one of the other discount brands and still only had rear brakes. Replaced with CPP Booster and PPV combo, blead the brakes once and was good to go,worked great.

[Classicman]

Well I tink is the P valve because the Booster new !!
Hey Keith how can I check the pressure and what tool do I need it?
Thanks for you help ..

[68gmsee]

Originally Posted by Classicman

Well I tink is the P valve because the Booster new !!
Hey Keith how can I check the pressure and what tool do I need it?
Thanks for you help ..

Don't need to check the pressure unless you're at a total dead end. Check the prop valve to make sure it's correct and the other possibilities mentioned. I will add a few more.

There's an adjustment of the booster push rod to the master cylinder that has to be dead on so check that also (scroll to section 5). I made my own gauge for this.

Possibility of defective brake shoes or defective new booster.

[WIDESIDE72]

In addition to the other things mentioned above, how old are the front brake hoses? If they are old original or inferior repros, they may be bad. When rhey go bad, the inside swells under pressure, not letting the full brake pressure to the front brakes.

[LA72c10]

I'm still having this issue with my 72 disc/drum and it sure seems like a more common issue with the disc setup. My truck has a twist though...It started with no front brakes directly after replacing all the components up front. Tried bleeding and stomping pedals or cracking rear bleeders but still no luck. Put it away for winter and the following spring replaced all rear brake components including cylinders and next thing you know the problem jumped to the rear brakes so now i have front brakes again. Changed the m/c after bench bleed and and still no luck. Bought the prop valve center tool that screws into brake light sensor and it actually bent the tool during standard bleeding. My last stop is now going to be the proportioning valve...although a friend informed me I might have better luck with a pressure bleeder? LMC sells prop valves for $150 so that seems to be my last option. (My shop manual says if you see any brake fluid inside the brake light sensor port after removing the sensor then your pressure seal inside the valve could be pooched, I happened to see a small amount in mine so not sure if it should be dry or a little is ok?)

Good luck hope this helps all of us lol.