Quote:
Originally Posted by Robznob11
Ok im dealing with this same issue. the master I have on my truck looks like the third on the page and was bolted to a 11" booster. I took it off a donor cab of unknown origin(67-72 chevy or gmc?).
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The MC my neigbor pulled off has what appears to be a
larger bore than the new MC. I was a little baffled. I have no idea what it is at the moment. I need to dissect this bugger and figure out what the hell was on the truck. Eyeballing it the MC pulled off might be 1-1/4", the bore looks bigger. The new MC is overall, considerably bigger. As my neighbor stated "That's a TRUCK MC there, boy." Comparing the two Centric photos, they are actually that much different in size, 130.64001 is a MONSTER of an MC. I'll definitely have to take pics once we get this sorted.
Quote:
Originally Posted by Robznob11
I was looking into what master to run ece and cpp both told me that a stock 71/72 disc drum master will bolt right up even though it is 1 1/8 as opposed to 1" of the oe master. now my question is the 71ish capriece master is disc drum and 1 1/8 I like it because it is 26 bucks as opposed to the 45 bucks for the truck one. so what gives is it ok to run the car master.
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This was also one of the idiosyncrasies that was pissing me off.
It seemed depending on what time and day of the week it was, I was getting up to five different MCs for the same damn vehicle. It was stupefying. Fact of the matter is there are eight different MCs that were used. Disc or Drum, Manual or Power, and is the MC a Bendix or a Moraine unit.
Bastards.
To simplify your answer, the '70 Caprice PB Disc Moraine MC, and the '72 C10 PB Disc Moraine MC are one in the same. Look up both via RockAuto.com and you will find the same PN, Centric 130.64001.
1" MC is for Manual Brakes
1-1/8" MC is for Power Brakes.
Oh and the Booster under hood has an adjustable rod so I just backed it off .01". Woot.
Quote:
Originally Posted by Robznob11
also im running a preportion valve from a 85 donor with one front line plugged.
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Proportional valves found on production cars are not really proportional. Actually they are combination valves. First it is a junction block for all the lines, with a metering valve for the front brakes, along with a pseudo proportional valve, and finally a shuttle valve to close off a leaking part of the system which also activates the 'brake' light switch due to a system failure.
We are leaving the stock junction/metering block on the truck for now, and will add an additional proportional valve if we find that the rears need less bias.
Reusing a factory combo valve in another vehicle that is not the original application is more than likely not going to be correct at best. Although these trucks share a lot of common or near common parts; weight distribution, balance, and braking performance will differ greatly affecting the accuracy of a pre-programed combo valve. With the adjustable unit we can fine tune the truck for braking when laden or not... if we remember to, HAH!
Ideally if there was some kind of level sensing valve we could install that would be awesome, but I know of no such valve that was used on these trucks.
Just need to get the Fleetwood WCs installed, and get the brakes bled and see how she go's, err stops. But the rain has been coming down, not really the best weather when there's 100% humidity and the fluid you are working with is hygroscopic, bah.