MC/Booster Help

Nuzzy · Feb 21, 2007

Need to start addressing the brakes on my jeep. Will be 60/14 disc/drum to start but will shortly change to rear disc as well. After much research on Pirate, I'm thinking my best option is a '69 Vette power brakes MC for bolt up ease. Plus it was designed for 4 wheel disc. Everyone seemed to be saying it should cost $30. So I stop by Napa today to check prices/availablity out...

So here's my questions:

A) My stock CJ vacuum booster needs to be replaced cause it leaks. Should I just replace it assuming it's sufficient or should I take the opportunity to upgrade to a newer style Hydrobooster? Or would that be more work than it's worth? Napa quoted $104 for a replacement vacuum booster.

B) If I stick with the vacuum booster, the 69 vette mc should bolt right up. If I went with a newer hydrobooster, I would prob then just go to a Grand Marque (i think that's what it was) mc. Now here's the thing... Napa quoted $75 for the vette mc which seemed really high based on the research I did...

Anyone have thoughts...??

CrustyJeep · Feb 21, 2007

Will a mid 70's Chevy pickup booster bolt in? That would get my vote. You get a nice selection of cheap and readily available master cylinders to match. I would get a booster from a 3/4 ton, and a master from a 1/2 ton to start, then upgrade the master to 3/4 or 1 ton with the rear disks. Any parts store that doesn't keep those master cylinders in stock is useless.

Nuzzy · Feb 21, 2007

CrustyJeep said:
Will a mid 70's Chevy pickup booster bolt in?

Not sure. Guess I'd have to see how it bolds up and the pedal assembly. If it's a pain to make work, I don't want to worry about at this point cause god knows I need something else making the build take longer. But I'm totally game for any basically bolt in part...

What about newer jeep model hydroboosters? Seems they might be a closer fit wouldn't they?

CrustyJeep · Feb 21, 2007

Well at any rate, I'm fairly certain the mid 70's Chev truck MC's will bolt to your factory booster. They bolt to my factory '76 booster anyway, and work well.

Nuzzy · Feb 21, 2007

CrustyJeep said:
Well at any rate, I'm fairly certain the mid 70's Chev truck MC's will bolt to your factory booster. They bolt to my factory '76 booster anyway, and work well.

And your factory booster is vacuum, right? Not hydro...?

Bunk1 · Feb 21, 2007

Dont forget about about the rear discs with the 70's truck mc. Secondly the hydroboost may fawk with yer hydro steering, I dont know the full implications so im just saying it out loud. Did you ever get a remote reservoir?

Nuzzy · Feb 21, 2007

Interesting responses. http://www.pirate4x4.com/forum/showthread.php?t=286271&highlight=hydrobooster

Didn't even think about the extra consumption of steering fluid... I'll already be pretty maxed out til I can upgrade my whole hydro steering to include extra capacity. Might need to hold off...

CrustyJeep · Feb 21, 2007

Nuzzy said:
And your factory booster is vacuum, right? Not hydro...?

Right.

I know very little about hydro, but I have driven 1 ton trucks with it, and I seem to remember it sucks even worse than vacuum when the engine dies, so that might be a consideration.

Nuzzy · Feb 21, 2007

Bunk said:
Did you ever get a remote reservoir?

Not yet. Gonna run a few shakedowns without to see how it does. Will DEFINITELY buy later on but will put off for the time being if possible.

CrustyJeep · Feb 21, 2007

Bunk said:
Dont forget about about the rear discs with the 70's truck mc.

Meaning what? Works great on ours

Nuzzy · Feb 21, 2007

CrustyJeep said:
Meaning what? Works great on ours

Does your MC have residual valves that you had to change to run discs in the rear? I read that rear drums use a 10psi residual valve and that discs needed 2psi to run properly without dragging... Also, what did you do for a proportioning valve?

Bunk1 · Feb 21, 2007

CrustyJeep said:
Meaning what? Works great on ours

Ever try to lock up all 4 tires during yer rigs 2 Month period of wheeling with that master???:flipoff:

CrustyJeep · Feb 21, 2007

Nuzzy said:
Does your MC have residual valves that you had to change to run discs in the rear? I read that rear drums use a 10psi residual valve and that discs needed 2psi to run properly without dragging... Also, what did you do for a proportioning valve?

I'm pretty sure there's no residual valve in the MC. That's one of the functions of a combo valve.

CrustyJeep · Feb 21, 2007

Bunk said:
Ever try to lock up all 4 tires during yer rigs 2 Month period of wheeling with that master???:flipoff:

It wont lock the fronts on dry pavement. I need more boostage, and I could probably use a smaller M/C. I'm running a 1-1/4" MC off a 3/4 ton. The 1/2 tons ran a 1-1/8", same as the corvette MC everybody loves.

But, the pedal feels great and the brakes have never come up lacking on the trail.