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OK, guys; I can use some help thinking through my 4-wheel disc setup. Here's what will be on each end:
Front: 1988 Dodge D60 with 2 3/8" bore calipers, stock setup.
Rear: 1977 GM 14-bolt with Sky brackets, front 3/4-ton rotors and '77 Eldorado calipers with integral e-brake.
Going down the line, here's my questions:
* Which master-cylinder should I use to activate these four discs??? I was thinking of a '77 Eldorado MC, which would have the capacity and proper valving for the rear calipers, and being an ordinary Delco design, would bolt onto the factory power-booster. My only concern would be the capacity for the front calipers. Web-pages for disc setups have mentioned early-70's P30 (Chevy heavy van) MC's as having sufficient capacity for big-bore front calipers and for rear calipers as well. Just have to remove the residual valve for the rear circuit and go.
* Routing the lines/choosing proportioning valve.
First, the front axle: The front lines on a dodge are set up like the rear lines: flex hoses to each caliper, connected to a hard-line on the axle going to a junction-block, and a single hose from the junction block to the chassis. I could keep this setup, and bend a new line so the junction block is on the driver's-side. Then I could route a single hydraulic hose along the top of the leaf-spring up to the chassis. With that setup, I wouldn't have to worry about suspension-flex maxing out the hose-travel. The other option is to stick to the factory Jeep routing, and then just run a single long hose from the frame to each caliper individually. I'm leaning toward the Dodge setup.
Second, the combination valve: If I have a single line to the front and to the rear, I could route each line directly to the proper port on the master-cylinder, and do away with the combination valve. Besides distributing brake pressure and providing a hookup for the "Brake" warning light, the stock proportioning valve also modulates the front and rear pressure balance so that the rears don't lock up before the front. Going to all discs is going to toss the calibration of the factory modulation out the window, so I was going to simply install an adjustable proportioning valve in the rear line and adjust that to prevent rear lockup. I would lose the "Brake" warning-light function, but on the rare instance that I've had that light come on, I DIDN'T need that light on to tell me I had lost my brakes!!! Other option is to buy a $99 4-wheel disc specific combination valve and stick with the factory routing. I'm leaning toward doing away with the combo valve.
Any thoughts or insights appreciated.
Front: 1988 Dodge D60 with 2 3/8" bore calipers, stock setup.
Rear: 1977 GM 14-bolt with Sky brackets, front 3/4-ton rotors and '77 Eldorado calipers with integral e-brake.
Going down the line, here's my questions:
* Which master-cylinder should I use to activate these four discs??? I was thinking of a '77 Eldorado MC, which would have the capacity and proper valving for the rear calipers, and being an ordinary Delco design, would bolt onto the factory power-booster. My only concern would be the capacity for the front calipers. Web-pages for disc setups have mentioned early-70's P30 (Chevy heavy van) MC's as having sufficient capacity for big-bore front calipers and for rear calipers as well. Just have to remove the residual valve for the rear circuit and go.
* Routing the lines/choosing proportioning valve.
First, the front axle: The front lines on a dodge are set up like the rear lines: flex hoses to each caliper, connected to a hard-line on the axle going to a junction-block, and a single hose from the junction block to the chassis. I could keep this setup, and bend a new line so the junction block is on the driver's-side. Then I could route a single hydraulic hose along the top of the leaf-spring up to the chassis. With that setup, I wouldn't have to worry about suspension-flex maxing out the hose-travel. The other option is to stick to the factory Jeep routing, and then just run a single long hose from the frame to each caliper individually. I'm leaning toward the Dodge setup.
Second, the combination valve: If I have a single line to the front and to the rear, I could route each line directly to the proper port on the master-cylinder, and do away with the combination valve. Besides distributing brake pressure and providing a hookup for the "Brake" warning light, the stock proportioning valve also modulates the front and rear pressure balance so that the rears don't lock up before the front. Going to all discs is going to toss the calibration of the factory modulation out the window, so I was going to simply install an adjustable proportioning valve in the rear line and adjust that to prevent rear lockup. I would lose the "Brake" warning-light function, but on the rare instance that I've had that light come on, I DIDN'T need that light on to tell me I had lost my brakes!!! Other option is to buy a $99 4-wheel disc specific combination valve and stick with the factory routing. I'm leaning toward doing away with the combo valve.
Any thoughts or insights appreciated.
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