Power booster question
 

I’m going to replace the leaky stock booster with a used power booster. I need to know where the vacuum line gets connected.
And if anyone has some insight to what to look out for or any tricks would also be helpful. Seems to be a simple install though.
Thanks.
DMX

Re: Power booster question
 

The vac line goes to the intake. There should be a port behind the carb. I would do a search on the board for the install tricks.

Re: Power booster question
 

Got the old unit out but…..the rod is different on the power booster. The pedal pivot bolt is smaller than the one on the GMC. I’m now wondering if I can drill this up to the correct size. Is there a source for replacement rods?
DMX

Re: Power booster question
 

Ok, now this won’t work at all, it seems that the hole pattern is different too. :confused:
So now I need a power booster. I’ll try to fix the leak on the old unit for now.
DMX

Not all master cylinders alike.
 

I spent half the day talking to parts stores for a power booster and/or master cylinder. :crazy:
All the power boosters’ setup’s had studs for mounting directly to the firewall. (Don’t we need the bracket that will stand it off the FW a little?)
One guy at Napa dredged up a picture of one that required some sort of cantilever set up to operate- don’t think mine needs that.

The master cylinders are another story…..some of them came out with an older unit that takes two clamps for the lid. I wanted the newer style (like I had) and after calling a few stores found it. It’s a reman unit by Cordone (sp) same as what Napa sells.

Question: If I go to a junk yard, what year models do I look for to get a Power booster out of? Can the bracket be bought separately?
Any help will be greatly appreciated.
DMX

Re: Power booster question
 

Can you post a pic of what you have now? A pic is worth a thousand words. That'll help us tell you exactly what you need.

Re: Power booster question
 

the booster they were gonna sell you needs to be bolted onto the stand that would have come with the truck... so even with a reman unit (I HIGHLY recomend that route) you still need junk yard parts.
A blown booster can ruin your day... big time, even if you don't total your truck, and/or kills someone/yourself/your family in the truck... you can blow your engine when the booster diaphram pops... not likley, but, I had the blown engine to show for it.
Even if you test a used one and it seems good, the fact of the matter is, there was probably some brake fluid in there at one point, and it is just a matter of time before the robber goes.
I may be the cheapest guy you'll ever meet, but I will not run a used booster. (again)
I even went as far as to remove my blown booster, and go with manual brakes for now.

Re: Power booster question
 

Thanks Longhorn Man, good info & great advice!
I’ve had power booster fail before on my father-n-laws F-350 & it takes allot of pressure to stop and this may be easy compared to these old trucks?

I’ve been searching for a used unit to get the bracket and necessary linkage. I had originally thought there was a unit that had the support bracket that bolted up (without the weird linkage stuff) but finding out otherwise. Why do they use that lever system anyway- couldn’t thay just make a bracket that allowed the rod to go directly to the brake pedal?
I may just keep manual brakes for a while too, it isn’t that bad.
Will you ever go back to power brakes?-sounds like you had a rough time when it went, not just hard brakes but with the loss of the motor = no power steering! :ack:
DMX

Re: Power booster question
 

well, mine is a one ton... and I am assuming yours is a 1/2 ton... I never had a 1/2 ton with a booster, but I know on my one ton, when the booster went, or if I shut it off and coasted(why do we do idiotic things like try to coast 3 miles???) when it'd run out of vacume, my pedal was ROCK hard, and i felt like I was slammong my foot on the floor board... it was that hard to stop.
Again, this may be apples to oranges... but it's stull fruit. ;)
I'll go back to power one day, but not untill i convert to discs up front. I refuse to spend that kind of money on a new booster only to swap it out in the next year or so (I hope)
When i lost my motor, it didn't lock up, the piston skirt shattered in one cylinder, and I lost all oil pressure when the chunks got in the oil pump. So i actually drove it to the side of the road when it gernaded. Heck, after rebuilding the oil pump (not knowing exactly what was up) I limped another 50 - 75 miles on it on 7 cylinders. (that cad torque still let my burn all thought 1st gear) Sucker sounded like a 6.2/6.5 diesel.... pretty sick really.

Re: Power booster question
 

There is some good info on swapping booster in this thread.

http://67-72chevytrucks.com/vboard/s...d.php?t=215980

Any booster from a 73-87 truck should work. You need to extend the rod from the newer style boosters and drill another couple of holes in the booster bracket but, other than that, it is a "bolt-on" modification.

Re: Power booster question
 

Hasve you thought about going to a supplier that is on the Internet. SSBC or BMB, these guys have the boosters that have everything that you would need. The cantilever thing is to get the booster high enough to clear the valve covers and to change the rod input rate to the booster. That is not an absolute needed item, but the clearance is a serious thing on these trucks. The bolts that holds the booster should already be on the bracket from the steering column mount and fitted through the firewall. As for a new rod end, these are also found everywhere. Have you tried a salvage yard for parts?

Re: Power booster question
 

That’s exactly what I was looking for, thanks. I have one that came with the spare parts with the truck & the rod is too long. I can always use it for a core charge though.
I just finished installing a re-man manual unit for now, but I like how the newer ones
look. Especially how you have the portioning valve!

I considered powder coating my master cylinder but wasn’t sure about heating it up to bake the powder coating. So I just installed it, I might do the lid later.
Thanks for all the help.
DMX

Re: Power booster question
 

I plan on hitting the salvage yard next week if the weather is good. I think I’ll look for a tilt steering wheel and some alternator & power steering brackets- mine are Buttco, :dohh:but that’s going to be a separate thread, I’ve got to finish bleeding my brakes.

Re: Power booster question
 

If you happen to have a Power booster that is the gold iridite finish; that can be polished and made really shiney, with a gold tint. The powder coating will work if you take the booster completely apart and then rebuild it after coating. Buy a chrome one and install it for the same amount of money and less pain.

Re: Power booster question
 

Good info, I have all the polishing stuff in my shop too. My powder coating free, just my time to remove & prep. :metal:

I got the brakes done and did a test drive. It stops pretty good actually, but if you hit it pretty hard on gravel the last 2 feet it will skid the L front tire.- not bad IMO. It barely pulls to the left if you hit it had on pavement without holding the steering wheel. Not even enough to worry about. I’m not sure how to correct this anyway.
DMX