What is the brake pedal Supposed to feel like!?!

[86chevyk20]

My 86k20 has all new lines and brake pads, shoes, hardware,calipers EVERYTHING! But i did clean out and reuse the proportioning valve, witch is working fine

Bled it out and the pedal still feels too low to me.

Im not sure how high,hard these trucks are supposed to me.

10.5 axle in back, corp 10up front.

so how hard, are these pedals supposed to be and are they normally pushed lower before they grab or do they start to grab high.

 

[chubble]

Mine has a good amount of squish to it. I don't know if that is how its supposed to be. I would probably say the first 1-2 inches is squish before it grabs and is down pretty solid at each stop.

 

[Boone83K10]

book says 1-1.5 inches pedal travel to allow proportion valve to engage drums before the discs grab on the front.

 

[dhamp]

What are you comparing it to? What's your DD? Reason I ask is I had to catch myself from comparing my 25 year old truck w/25-year old non-HD braking system to my '03 Maxima and the '13 F-150 I drive at work everyday. Then, after I drive my square for a day or two, I get back in one of the other rides and damn near through myself through the windshield a few times before I recalibrate back to that.

 

[89Suburban]

http://www.gmsquarebody.com/forum/showthread.php?p=157800&highlight=pedal#post157800

http://www.gmsquarebody.com/forum/search.php?searchid=666733

 

[chengny]

There are a couple of really good points here. Especially the loose wheel bearings cause - never occurred to me. The calipers are working properly but must recover the pad/rotor clearance with every new brake application:

Low Pedal


CAUSES


•Excessive clearance between shoes/linings and drums. The brake pedal will feel solid and the vehicle will have sufficient braking power, but the pedal travel will be excessive (greater than 1/3 of total travel).


NOTE: If the brake system is operating properly, the amount of pedal travel is proportional to the distance that the brake system has to extend the pads or shoes.

This distance is normally controlled by the adjustment of the rear shoes/linings, since the disc brakes readjust themselves with every application. Keep in mind that if the shoes/linings are loose, the emergency brake will also be loose, since it applies the rear brakes.

•Excessive lateral runout (rotor wobble) or loose wheel bearings. The pads/linings can be knocked further back into the calipers than usual by excessive rotor wobble. This requires more brake fluid behind the pistons to extend the pads back into contact with the rotors. This results in longer pedal travel.

WHAT TO CHECK FOR


•Check the adjustment of the rear shoes/linings, and adjust if necessary.
NOTE: The shoes/linings are normally automatically adjusted. If you have to adjust the brakes more than once, you should inspect the operation of the auto-adjusters. Remove, clean, and lubricate the automatic adjusters as necessary.

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•Check the wheel bearing adjustment, and adjust if necessary.

•If a pedal pulsation is also occurring, inspect the rotors for excessive lateral runout. Resurface or replace if necessary.

 

[86chevyk20]

great info! i adjusted my rear drums the other day until i felt them start to grab. would this be enough or go more? And again everything is brand new.

 

[86chevyk20]

Not really comparing it to anything. I drive a 2013 silverado so i know there would be no comparison. I just know that my pedal is too low, it seems. I can try to bleed it again. And i made a mistake. i am useing the orginal master cylinder. I never had a problem with it.

 

[chengny]

Im not sure how high,hard these trucks are supposed to me


I used to drive an 86 3/4 ton equipped with vacuum assist power brakes:

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Just as reference - there was virtually no lost motion. The brakes would respond with just the slighest touch to the pedal.


My 86k20 has all new lines and brake pads, shoes, hardware,calipers EVERYTHING! But i did clean out and reuse the proportioning valve, witch is working fine

Bled it out and the pedal still feels too low to me.

When I saw the word "EVERYTHING!" - well... I kind of just assumed the M/C had been replaced. I would renew a 27 year old master if you are looking for optimal braking response.