What kind of Master Cylinder would I use? 4 wheel disc

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Judge Mills

1971 Plymouth Duster
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I have a 71' Duster. I now have a 97' Explorer rear with disc brakes. I will soon have 73' A body front disc brakes. Which master cylinder should I use? Would a stock one work?
 
I know there are a few people on here that have 4 wheel discs. Is it a possibility to use a stock style MC with a proper adjustment on a adjustable proportioning valve? If I am thinking correctly, drum brakes require more pressure than discs, so if I reduced the pressure to the rear, would that work?
 
Judge Mills said:
I know there are a few people on here that have 4 wheel discs. Is it a possibility to use a stock style MC with a proper adjustment on a adjustable proportioning valve? If I am thinking correctly, drum brakes require more pressure than discs, so if I reduced the pressure to the rear, would that work?
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I used the stock MC and added an adjustable proportioning on my 4 wheel disc application and it has worked well. I frequently drive the car at 100 plus mph applications. i did this because it was easy and I didn't know any better??

CAUTION---I HAVE READ TO NOT USE A DISK/DRUM MC BECAUSE IT WONT WORK AND YOUR REAR TIRES WILL LOCK UP. (something about an internal valve in the drum cylinder?????????/

My REAR TIRES HAVE NOT LOCKED UP IN 4000 MILES AND I AM STAYING WITH MY SET-UP PLUS THE PROP VALVE WORKS GREAT
 
Right.. It seems to me if I remember correctly, everyone seems to be using stock style MC's on this board. Just a quick look in the Summit catelog doesn't note 4 wheel disc or 2 disk/2 drum.

I think the internal thing may be a residual valve. It keeps a certain amount of preassure in the line for drum brakes. Disc brakes don't require them, or require one with a lot less preassure, it's one of the two. I haven't figured that out yet. I am not sure if these are build into the MC or if they are in line of the brake line. I see them for sale in Summit that just go in line of the brake line.
 
If you are going through the cost and trouble of putting rear disc on your car, the MC is not a good place to cut cost.


http://www.mpbrakes.com/technical-support/troubleshooting-disc-01.cfm

When you add disc brakes to the rear you must use a true 4 wheel disc master cylinder. The pressure and volume requirements to the rear are much greater than that required by drums, disc brakes require more pressure and volume. A four wheel disc master will have a longer stroke and will provide more pressure to the rear disc brakes.
 
If your looking to use a stock master,at least choose one with a bigger bore than your drum master.
 
1968FormulaS340 said:
If you are going through the cost and trouble of putting rear disc on your car, the MC is not a good place to cut cost.


http://www.mpbrakes.com/technical-support/troubleshooting-disc-01.cfm

When you add disc brakes to the rear you must use a true 4 wheel disc master cylinder. The pressure and volume requirements to the rear are much greater than that required by drums, disc brakes require more pressure and volume. A four wheel disc master will have a longer stroke and will provide more pressure to the rear disc brakes.
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I thought the pressure requirements for disc was lower than drum? I was wrong! Indeed I do not want to cheap out on this, I just couldn't find info on 4 wheel disc MC's, which is why I started this thread. Thanks for the info!
 
I have 4 wheel disc on my 1970 DUSTPAN340....I'm using a Corvette MC.....with a ajustable porportioning valve
 
Go to the Wilwood site and look at what they offer. I'm running their brakes, front and rear with their MC.

Bill S.
 
I can get you pics...car is in the body shop...will be out tuesday...I can drive over monday to shoot some pics...did not drill new holes..and hooked up to stock pedal...I know..a GM part in a MOPAR...but...it worked...
 
DUSTPAN340 said:
I can get you pics...car is in the body shop...will be out tuesday...I can drive over monday to shoot some pics...did not drill new holes..and hooked up to stock pedal...I know..a GM part in a MOPAR...but...it worked...
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That would be awesome! Thank you. Don't feel bad, I have a Ford 8.8 out back :)
 
i have 4 wheel disc and i got everything from dr.diff master cylinder -valve and used manual rod and it works great!
 
I am in the process of installing a Master Power four wheel disc brake kit as we speak. It came with a rebuilt master cyl similar to what came stock on BBP A bodies. Modifications have to be made to the stock proportioning valve (basically gutting it) which turns it into a distribution block. We are going to add an adjustable proportioning valve on the left rear frame rail so that we can make adjustments as necessary.
 
What year Corvette for the mc? Did you have to modify the rod behind it?? I just love when oem parts can be used; saves a lot of $$$.
 
MoparCrazy78 said:
What year Corvette for the mc? Did you have to modify the rod behind it?? I just love when oem parts can be used; saves a lot of $$$.
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my buddy just told me it was off a 84 Vette...and no mods...i'll post pic since I just pulled the motor out and redoing the engine bay...
 
i have a exploder rear axle with disc brakes in my 87 5th ave, and using the original master cylinder and puportioning valve with no issues
 
Anyone else figure this out i thought a factory disc master with an adjustable proportioning valve would be fine for my explorer disc rear.
 
Judge Mills said:
That's for sure. I wasn't planning on using my stock, 4 drum, non-power master cylinder. That's a death wish :cheers:
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Horse ****.

Every car is going to be different, here is some of the stuff that is gonna affect pedal pressure AND proportioning

Bore size of the calipers and rotor size

Bore size of the master

Engine size and weight

Tire size, type, brand, compound, and outer diameter

Weight typically in the car

MY OWN case:

67 Dart smallblock 727, with a Lincoln Versailles (9") disc brake rear and Duster front discs.

"Just to try" I am using the (67) FACTORY DRUM MANUAL cylinder and it just happened to work just fine. This cylinder has (had) residual valves in the ports, and I simply used a nail to puncture the rubbers

Proportioning is great, pedal pressure is fine for my weak old legs, and the only thing you need to do is check the brake fluid "once in a while." Mine didn't move in the season I had this combo on the road. (Torn down presently for paint)
 
67Dart273 said:
Horse ****.

Every car is going to be different, here is some of the stuff that is gonna affect pedal pressure AND proportioning

Bore size of the calipers and rotor size

Bore size of the master

Engine size and weight

Tire size, type, brand, compound, and outer diameter

Weight typically in the car

MY OWN case:

67 Dart smallblock 727, with a Lincoln Versailles (9") disc brake rear and Duster front discs.

"Just to try" I am using the (67) FACTORY DRUM MANUAL cylinder and it just happened to work just fine. This cylinder has (had) residual valves in the ports, and I simply used a nail to puncture the rubbers

Proportioning is great, pedal pressure is fine for my weak old legs, and the only thing you need to do is check the brake fluid "once in a while." Mine didn't move in the season I had this combo on the road. (Torn down presently for paint)
Click to expand...

agree w/ dart273, a lot of b.s. in here >
 
I am running 4 wheel disc brakes with 4 piston calipers in the front and explorer calipers in the rear with an aluminum stock style master cylinder and stock proportioning valve and the car stops great, no need for adjustable proportioning valve. I have done a few panic stops to test them out and the car stops fast and straight.
 
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