How do I know what part is bad

[vectorit]

Well, this last weekend I took my burb out for it's first time out on the road in a very long time. But noticed right away my breaks were not all that good, so I am worried that all this time sitting something went bad.
I had installed a new power booster and master cylinder maybe 8 years ago, and I am woried that over time the power booster went bad... Is there a way I can tell what part is not working 100 percent before I start taking things apart, and having to spend a lot of money on a new booster again? My gut is telling me that the booster has failed, but I am just hoping that there may be something else to look at.
Currently the break pedal is very hard, and the trucks breaks are not gripping well. Meening I couldn't stop in an emergency if I had to.
Before I pulled out of my drive way I pressed hard on the pedal to check if I had good break control, and one rear tire locked and made a little scid mark. But after doing that I can't seem to do it again, and now if you listen while the truck is rolling slow you can hear a clicking noise from that rear wheel.

Any comments on what I should look at first, and if there is a sure fire way to tell if a booster is bad other than a pedal test?

Thanks!

[primered_junk]

I would check rear wheel cylinders first make sure the have not froze up, or a stuck adjuster or broken hardware generally a clicking sound is a bad thing. If the pedal is still rock hard after that I would lean towards the booster. If the pedal is equally as hard when it's not running as it is with it running it would be the booster.

[watahyahknow]

i would first check if the vacuumhose going to the booster is still airtight and hooked up .
then check if the wheel cylinders are ok it only takes a little water over time to make them go bad .
get the brakehub off the axle and stick a small blunt screwdriver under the cup on each side and lift the seal if theres fluid dripping out the cylinders are bad while the hub is off you can clean everything too and make sure it still moves like it should .
not sure if these trucks have a brakebalance above the rearaxle (follow the brakelines it should be somewhere in the middle conected to the axle by a rod ) that might ve been stuck as whell couple of hits with a hammer on the lever and some wd40 might fix that .

[cdowns]

surface rust on brake drums and rotors from nonuse will cause poor brake performance//i'd spend an hour of aggressive driving and braking to see if the performance improves / i'd also b checking the thickness of brake shoes and pads

[ratrod67]

Originally Posted by cdowns

surface rust on brake drums and rotors from nonuse will cause poor brake performance//i'd spend an hour of aggressive driving and braking to see if the performance improves / i'd also b checking the thickness of brake shoes and pads

Why would you tell someone who's brakes aren't functioning properly to "spend an hour of aggressive driving and braking"? There are better ways of cleaning off surface rust than to put him in danger.

[cdowns]

Originally Posted by ratrod67

Why would you tell someone who's brakes aren't functioning properly to "spend an hour of aggressive driving and braking"? There are better ways of cleaning off surface rust than to put him in danger.

i didnt tell anybody to do anything i just stated what i'd do!! and with close to 45years of driving experience i feel quite comfortable doing what i do well

[watahyahknow]

like dismounting them and take a piece of sandpaper to the shoes and inside of the drum .
check the edge of the drums to see if theres wetness if there is you need to replace the shoes as whell because there soaked in oil and will never brake the way they did before

[screamin_eagle]

I'd agree with cdowns just as long as you where your seat belt and a helmet.

[vectorit]

Well, if I had a big parking lot close by I would do some hard stops back and forth. But I don't and street is out of the question, since I have a lot of little ones running around the neighborhood.
I did some close inspections a bit ago, and found that when in storage I did have a leak from the front driverside wheel cylinder. I gues that would explane why my break fluid was low in the master.
I am dreading taking apart my breaks! Since the fronts are on a closed knuckle D-44, and the rear is a 3/4 ton Eaton full floater wich will be easier that the fronts I guess.
I think if I am going to make that commitment to taking all that apart, I might as well rebuild every corner while I am at it. Since its just too much work to just take everything apart to just "look at it"...
So, does anyone have a recomendation as to who might sell complete drum break rebuild kits for a 68 K20? I know the usuall suspects like LMC, Brothers, OC car&Truck shop etc. etc., and I have had pretty much bad experiences with all of them. So its pick my poison I guess, just wondering if there might be someone else that you guys would know about?