Brake booster problems

[Americanrider]

Finished the install on my 67 K20. New MC from Napa, (matched Delco-Moraine to the booster) Dual chamber booster & P-value from a 72 K20, new lines to a '75 Dana 44 Disk brake front end. I've bled each rear corner 3 times, the fronts 4 times. Getting clear brake fulid from all with no bubbles. Still have the warning light (even after trying the reset button) and the pedal only gives goes down about 1/2 inch and is super hard. Vac line is hooked into the manifold, running the stock 2 barrel, on the stock 283. What am I doing wrong here?

[truckdude239]

is it adjusted right as to the light on its an prop valve cause that if you getting fuild its not triped so something is the pro valve causeing the light to come on. do you have an check vavle in the booster? the 1/2 pedal sounds like its out adjustment

[Americanrider]

Yes it has a check valve. The booster sucks without the hose (thumb over hole) when you push the pedal. I know what the purpose of the idiot light is for... Something is wrong, thats why the light is on. When bleeding the pedal goes to the floor like it should.

[Longhorn Man]

Do all 4 wheels turn by hand (jacked up naturally)

[krue]

OK, have you checked to see if the rod between the booster and master cylinder is adjusted properly? It wouldn't have anything to do with the light tho.

[Americanrider]

After doing a little brainstorming last night I'm thinking that the calipers are frozen. I purchased the complete axle second-hand and who knows how long it had been sitting out in the rainy NW weather. Since I got it in September it's been outside until 2 weeks ago when I rented a shop to finish up the work. The lines where plugged off but there was very little if any fluid in them when I connected the hoses.

The calipers are installed correct, new bleeder valves. All wheels spin when lifted, I just put on a different set of rims & tires last week.

As far as the rod goes I have done one adjustment on it, making it a little longer, also had adjust the stoplight switch (a major PITA, I love standing on my head under the dash!) to turn the brake lights off when the key is on.

This is a new [to me] system, so what would be the "correct adjustment?" I have reversed the booster linkage levers and lubed the lower pivot shaft so that the top ends do not knock on the firewall. Since I don't have free pedal travel it's hard to figure what adjustment on the rod is correct. How much travel should the upper rod have? With the pedal up there is about 3/8 inch between the booster lever arms and the firewall. The pic enclosed is not my truck but just as an example. The rounded ends of the lever now face the firewall.

I have a spare set of calipers I'm going to try next. It's a good thing 1/2 ton & 3/4 ton Dana 44's use the same caliper.

[Americanrider]

Ok a little progress report. I swapped the front calipers out with another set. Bled them out twice. Removed the brake rod and gave it about 3 full turns to make it longer. The upper rod & clevis running into the booster is now a little closer to the firewall.

The bleeding method I used was a hand held Mighty-vac pump since I'm a one-man show here. I pumped it up to 20+ lbs and opened the bleeders, getting clear fuild on both. Drove it down the block and still have a hard pedal and VERY little stopping power. The throw on the pedal from top is now about 2 inches. Suggestions anyone?

Also... I pulled the rubber cover from the reset button on the front of the P-block. The button itself is stuck down. Does anyone know how to get this to release and pop back out?