4 wheel disk, 4 bolt master cylinder options

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prorac1

prorac1

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1963 Plymouth valiant.

1974 E Body front discs

Ford Explorer 8.8 with rear discs

I'm considering going with the Dr Diff master cylinder and adapter plate.

But looking for what others have done.

Thanks. Eric

Front brakes
IMG_3370.JPG
 
abodyjoe said:
dr diff plate and master cyl is the way to go in my opinion.
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1987 dodge diplomat alum. master cyl, use the orig. splitter block for equal distribution to all 4 wheels, has about 2 times the brake pedal pressure of power brakes on my 68 4 wheel disc fastback. Happy w/ it ! Been a while but if I remember , I gave $38 for the master cyl. at o`riellies. a few yrs back. I did use an offset mount on it, 1/2" thick, 2 to 4 bolt adapter. U can lengthen the master cyl push rod ur self, no big deal. cut it in half, thread both pieces, put it back together w/ a threaded coupling, adjust it to the thickness of ur adapter, weld it it and then dress it up to make it pretty. I turned mine in a little lathe. WAY CHEAPER THAN BUYIN A BUNCH OF STUF AT INFLATED PRICES.
 
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The Dr diff master is the same as out of a 87 ram, that's what I use with my set up with jeep rear disks. You will need a adjustable proportional valve also.
 
halifaxhops said:
The Dr diff master is the same as out of a 87 ram, that's what I use with my set up with jeep rear disks. You will need a adjustable proportional valve also.
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no adjustable proportioning valve needed on mine ! equal pressure to all 4 , works great for 4 wheel discs.
 
Had to with mine the front calipers have more fluid than the back. I do love them though.
 
When I did my master cyl I was looking for an alumn one. They all came out cast iron. The one alum one I did find looked like it had been through a war. I just went with a wildwood one because I needed it right away.
 
I bought the dr diff one then had a engine fire, well it melted, realized it was the same as the one in my 87 w150, works fine. Do have a 8" PB though since I have a 440 in it.
 
Thank you very much for the replies guys.

On the Dodge pick up and diplomat master cylinders, I'm assuming the residual check valve for the factory rear drum brakes on those vehicles is in the proportioning valve and that the master cylinder doesn't hold pressure on the rear brakes?

Also, what size brake lines are you using?

3/16" all the way around? Or 3/16" front and 1/4" rear?

Did the pushrod thread pretty easily?

Thank you again for all the help. It is much appreciated.

Eric and Jason.
 
And here's another one I haven't been able to figure out?

The DR Diff "kit" claims that you don't need to extend your pushrod. How is that possible? I figure even if we use a 1/4" plate we're still going to have to extend the pushrod that much or more.

Thanks again for all the help guys. It's greatly appreciated. Eric
 
prorac1 said:
And here's another one I haven't been able to figure out?

The DR Diff "kit" claims that you don't need to extend your pushrod. How is that possible? I figure even if we use a 1/4" plate we're still going to have to extend the pushrod that much or more.

Thanks again for all the help guys. It's greatly appreciated. Eric
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Dr diff is correct. Stock pushrod is used because the master cyl isn’t drilled as far. The adapter plate spaces it perfect for the stock pushrod.
 
abodyjoe said:
Dr diff is correct. Stock pushrod is used because the master cyl isn’t drilled as far. The adapter plate spaces it perfect for the stock pushrod.
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Is that only his master cylinder or is that all of the plastic bodied late model ones?

Thanks, Eric
 
Not sure if all the plastic ones are the same but dr diffs are like that and I know the 85ish diplomats are like that. I’m sure there are others.
 
prorac1 said:
Thank you very much for the replies guys.

On the Dodge pick up and diplomat master cylinders, I'm assuming the residual check valve for the factory rear drum brakes on those vehicles is in the proportioning valve and that the master cylinder doesn't hold pressure on the rear brakes?

Also, what size brake lines are you using?

3/16" all the way around? Or 3/16" front and 1/4" rear?

Did the pushrod thread pretty easily?

Thank you again for all the help. It is much appreciated.

Eric and Jason.
Click to expand...

New 3/16" steel, like the factory used. new everything. The pushrod was no problem. I had to use an offset master cyl., it is the reason for the 1/2" , 4 to 2 hole adapter, so it would clear the valve cover. The diplomat master cyl. does not hold any pressure, no check valves anywhere on mine. Lke I said, the pedal feel is about twice what normal disc brake systems are, but my engine slows my car down pretty good when I let off of it..
 
Thank you very much for the information. I think with a dodge diplomat master cylinder we can make our own adapter out of quarter inch aluminum plate. This just might work, and by doing at our self will save Jason a lot of money. Thank you again. Eric and Jason

famous bob said:
New 3/16" steel, like the factory used. new everything. The pushrod was no problem. I had to use an offset master cyl., it is the reason for the 1/2" , 4 to 2 hole adapter, so it would clear the valve cover. The diplomat master cyl. does not hold any pressure, no check valves anywhere on mine. Lke I said, the pedal feel is about twice what normal disc brake systems are, but my engine slows my car down pretty good when I let off of it..
Click to expand...
 
prorac1 said:
Thank you very much for the information. I think with a dodge diplomat master cylinder we can make our own adapter out of quarter inch aluminum plate. This just might work, and by doing at our self will save Jason a lot of money. Thank you again. Eric and Jason
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u may not have to extend the rod (don`t know) with only a 1/4" adapter. But u might run into flex w/ it being that thin ??????
 
famous bob said:
u may not have to extend the rod (don`t know) with only a 1/4" adapter. But u might run into flex w/ it being that thin ??????
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I wouldn't think so. The original master cylinder mounted directly to the thin sheet metal of the firewall. So i would think it would be fine.
 
I don't carry the common (1 1/8" bore) '79 and newer D-150 master cylinder which is available from any parts store.

I offer passenger car spec 15/16" and 1 1/32" bore aluminum master cylinders, which look similar, however.

You can re-use the original push rod because the adapter plate compensates for the difference between the late model 2 hole and the original 4 hole master cylinder designs.
 
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