new k5 owner couple questions!

[Gufaw96]

to start i have a 1974 GMC jimmy with a 350 i believe it has the th350/203 but i havent been able to verify this its pretty nasty weather where im at in oregon atm, the truck has a 4" lift and a few bolt ons

i have been trying to do as much research as i can and been wandering the forums for a week or two before i decided to post the truck has manual locking hubs and no front drive line in atm, since i believe its a 203 does this mean it has a part time kit in it, when i try to shift the transfer case it seems to only have low netural and high not sure whats going on there

if it is a part time kit should it have more than the 3 options?

the next problem im having is the brakes when you press them to the floor its like setting a ebrake they dont return under there own power, i thought oh simple fix new mastercylnder and booster after new parts in and brakes bleed it is still doing the same thing i have pulled apart the fronts and they seem to be working fine the piston moves in and out freely and they arent loosing any fluids any guess's? tired of hooking foot under peddle to pull up to release brakes

ill try to post some pictures later as i know all forums love pictures

 

[wage92]

do you have drums in the back? Bad springs somewhere maybe...

 

[Gufaw96]

it does have rear drum brakes and im scared to take them apart lol i hate drum brakes i suppose this is the next logical step

 

[wage92]

only thing i can think of...haha

 

[airemdwn]

make sure the pedal and rod arent hanging up under the dash somewhere. A fallen bracket or harness, stray wires from the previous owner, maybe even a worn pivot point.

 

[Gufaw96]

that was the first thing i thought was hanging up the brakes and i lubed it all up, when i removed the booster i could move the rod freely in and out without much trouble the new one however i couldnt compress by hand so i assumed that was my problem right of the bat the truck sat for almost 9 years so it could be a number of things

 

[chulisohombre]

If say bad fluid from sitting. Air in the lines. Bad rear brake components. New brake spring kits are cheap. If rebuild that and check the fluid and push out all the old crap out if the lines from sitting would help too. The rear could be really out of adjustment and the weak old springs don't have enough force to pull the shoes back in and push the pedal back up to normal. I'd rebuild all the rear parts and make sure all the brake lines are good.

 

[bigred88]

x2^^^. If it's been sitting a while a full brake fluid flush, new wheel cylinders (they're cheap too, less than $10 each) and spring kit in the back.

Another thing- I know that the rubber brake lines close to the caliper/wheel cylinder can deteriorate on the inside, and sometimes when they do they will do so in a way that acts as a one way valve- little bits wear away only partly from the lining, and when you depress the pedal they'll allow fluid to pass, but as the fluid starts to travel the other way those flaps come up and block off flow. I have no clue if this could cause your symptoms, but they're fairly cheap too (around $50 for all four conrers) and you might as well swap them when you flush the system.

I don't know the pedal set up on the earlier trucks, and this example is from an AMC Spirit, so I have no idea if the set up is even remotely similar, but on the brake pedal in my Spirit there are two holes to bolt the master cylinder linkage to, but only one is correct. I think they used the same pedal in multiple cars, which is the reason for the two holes. If you bolt it to the wrong one, the brakes don't work right and goofy stuff happens with the pedal. So IF there are multiple mounting points, it's possible someone before you pulled it apart and didn't bolt it up to the right one. But like I said, I have zero experience with the older trucks and no clue what it looks like under there. Just an idea that came to mind.

 

[Gufaw96]

Thanks for the help I'm going to flush them all and pull apart the rears tonight the lines look to be in good shape but who knows on the inside