Need help fast possible booster?

[xHighOctanex]

I've Googled this for an hour or so, asked around, can't find crap. So last couple days brakes felt weird but they worked, slowly they got a little farther in the peddle, then randomly would be super stiff but worked fine. Well today going home coming down a hill hit the brakes and... Peddle to the floor barely slowed the truck pulled the ebrake which didn't help basically at all. Just flashed my lights (don't have a horn currently) and luckily a combination of nobody going across and me stopping right after the line kept me from crashing it. Got the truck home, same brake effectiveness the whole time, they work but not very well at all had to use my clutch to slow down mostly. So fluid in the reservoir - check no leaks around Mc or lines - check (pads are very meaty). Truck off pumped the brake it stiffened up held it steady started truck, it depresses slowly (there is still a bit above the peddle that just drops down before I hit any pressure), truck bogs pretty hard when I pump the peddle. Would like to resolve this as easily as possible, I hear a tiny vacuum leak up front but I can't find it exactly I feel like it'd coming from my tvv since I can pull the center line off and plug it and idle will drop then let go it'll raise then put it on and nothing changes. If it's vacuum I'd be happy, if it's an Mc or a booster I'm gonna buy both since the smart guy before me jb welded, siliconed mine together (along with sprayed great stuff in a rust hole and taped it over then plastidipped the whole truck over some pretty nice looking silver that's starting to show). So I was planning on doing those eventually anyways but this is my only drive able vehicle right now and really need to make it driveable again please help fast.

[Draker]

Doesn't sound like a booster to me. You should still have pedal.. just shit brakes even with a bad booster. But.. it's possible. You can test the booster pretty eady. Pull vacuum on the hose and if it bleeds off... well replace it.

[hooptylife]

My '79 620 did the exact same thing to me two months ago: pedal inconsistent, then all of a sudden *nothing there (glad neither of us got hurt). Only difference in symptoms is my pedal did not stiffen up after turning the truck off.

Not an expert here, but after taking everything apart and replacing all sorts of crap to no avail, i found the source of my problem was a bad seal around the piston in my master cylinder. It had just a small chip in the rubber, allowing fluid past and of course rendering the whole brake system useless due to the lack of pressure.

The $20 mc rebuild kit from rock auto fixed my issue. Its nice to push on the brakes now and not have a heart attack..

[xHighOctanex]

I think next paycheck I'm gonna look into doing both and go from there, my brakes are back now. I screwed around with a few vacuum lines that night but not sure if that is what fixed it, hopefully they'll last for a bit.

[datzenmike]

Get horn fixed! Get e brake adjusted. These are important safety devices that you allowed to let you down in an emergency. Learn from this.   

 

 

The T V V has no connection to the intake vacuum.

 

The brake booster and an automatic does use intake vacuum as well as the air cleaner . Make sure the booster hoses are tight. The in line one way valve between intake and booster should allow you to suck air on the intake side, but not on the booster side.

 

Pump brakes several times and hold down on the brake. Start engine. What you should see it the pedal drop an inch or so.... this is normal.

 

A failure of the booster would show as an extremely stiff hard pedal that does not depress very much. The brakes will work, but the effort is extreme.  

[xHighOctanex]

Yea I gotta adjust the ebrake been slacking on that. And the horn since I have a grant wheel the horn crop for it doesn't work I have to get some stuff from ace and make it work. Think I'm just gonna get a new horn and run it to a separate button or switch like my other 720 was.

[datzenmike]

Well, never lend your truck. People expect the clutch to be left of the brake, the gas on the far right and the horn to be on or center of the steering wheel.