dual master (i have searched)?

[glendale]

this question is for the guys that have gutted the master and ran a dual behind it. what master have you guys used? or basically let's focus on what bore size should i be looking for?thanks for any help.

[Niel Hoback]

If you are not changing wheel cylinder sizes, just tsick with the original 1 1/8" bore. Check out older 70's Ford masters. They are generally cheaper to buy.

[Robert Horne]

I put a 1994 Ford Bronco MC on my 38 Coupe, and still used the original pedal assembly.

1 1/8 bore. Has been working very good.

On my 48 Dodge, I put on a Mustang ll MC... worked good, still used orginal pedal assembly.

[Oldguy48]

I got one that was designed for a 1985 Dodge D150 1/2 ton pick-up. It has a 1 1/8" bore. Fenco part #NM1860. Bought it at Autozone for about $40, and it's new, not a rebuild. I changed my brake pedal to a hanging pedal in my P15, so the master cylinder is firewall mounted, but I don't see why it wouldn't work mounted behind your original master cylinder under the floor.

Wayne

[K_Jordan]

I copied Robert Horne and went with the Mustang II

[glendale]

i forgot one thing i do have disks up front. i have the olddaddy kit. i also plan on doing two other cars that are in my club we all have the same kit.

[Robert Horne]

I installed the 94 Bronco MC, that had disc in front, drum rear, even though

my 38 Coupe has drums front and rear. I plan on later installing disc in

my Coupe. The 94 Bronco MC does good with the drums front and rear,

and should do better when I install the disc.....

[Oldguy48]

i forgot one thing i do have disks up front. i have the olddaddy kit. i also plan on doing two other cars that are in my club we all have the same kit.

Oops....And I failed to mention that I also have Olddaddy's disc brake kit installed on mine. With 10" drum brakes on the rear. Works pretty well, although I am considering converting to power brakes.

[Don Coatney]

i forgot one thing i do have disks up front. i have the olddaddy kit. i also plan on doing two other cars that are in my club we all have the same kit.

As you have discs you should read this thread linked below. Master cylinder bore is critical with discs up front.

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=22469

[Scruffy49]

Full sized Bronco or Bronco 2 mc? I've got a complete 92 Ranger parts junker as a donor for my 49 truck, if you used a Bronco 2 master I'm covered...

[glendale]

As you have discs you should read this thread linked below. Master cylinder bore is critical with discs up front.

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=22469

Don i have read that thread like three times and I keep getting lost. Can you point in the right direction?

[glendale]

And thanks everyone I really appreciate it.

[Don Coatney]

Don i have read that thread like three times and I keep getting lost. Can you point in the right direction?

Posting # 80 (quoted below) explaines the MC bore size issue. You must read the entire thread for all the details.

Chet;

I have sent them pictures and I just got off the phone with them. They claim that the master cylinder they sent me with the 7/8" bore is the only one that will work with the GM calipers that I have been running for the past 5 years. I told them that I have found a master cylinder with a 15/16" bore but they claim it will require too much pedal pressure to make this 15/16" cylinder work. My original master cylinder has a 1 1/8" bore. However with the coumpound linkage supplied with there kit it will require more pedal pressure to do the same job. They say my problem is the front calipers are too small and they recommended I call PLYDO for a "fix". You will have this same issue if you instill front disc brakes using the small GM calipers. If you use larger calipers your stock rims will not fit. I stopped by the auto parts store this morning to inquire about the fittings you recommended. They did not have these fittings in stock but I really do not want to add any additional fittings to the brake lines. Each additional fitting is a potential problem. ECI also recommended I take a hole saw and drill holes through the frame of my car and route the brake lines to the outside of the fraim rail. I will not do this. Pasted below is an e-mail I got this morning in response to my inquires and my reply.

Ralph;

Thanks for your response. I went out to the shop and measured the new position of the brake pedal using your method and you are 100% correct. From its original position the brake pedal will move 1/4" to the right with your bracket. But this got me to thinking where did the "other" 1/4" disappear to? It did not take me too long to find it. Seems the clutch pedal now sits 1/4" to the left of its original location. Add to this the 1/8" side to side movement you said to not worry about and suddenly the clutch pedal is 3/8" to the left of its original position. By the way I bought an off the shelf oil lube bronze bushing from McMaster Carr to correct the brake pedal slop issue. The side to side clutch pedal movement is now close to factory tolerances.

My jury is still out on the tubing connection issues. It is my belief that any additional fittings added to the brake lines is asking for trouble. And your only soloution appears to be adding fittings or using a hole saw to drill a couple of holes through my frame neither sounds like a good soloution to me. I am past the point of no return on this project. I would like contact information of any of your customers who you say have overcome this situatuion.

Don Coatney

----- Original Message -----

From: "ENGINEERED COMPONENTS" <hotrodbrakes@sbcglobal.net>

To: doncoatney@comcast.net

Sent: Thursday, August 12, 2010 11:03:04 AM

Subject: Re: Dual Master Cylinder 48 Plymouth

Don, The very fact that it has a grease fitting, and that grease does come out along side the pedal bushing is why dirt collects on the grease. We have done this on all our assemblies for years without any problems. As far as your fitting problem that is a function of the brakes that you selected, not us. Since they are small piston GM calipers they require higher line pressure to function, and therefore need a 7/8 bore m/cyl. The only one that is available to be used in an unboosted situation is the cylinder we supplied. There is no other with outlets on the opposite side, which is why Bob suggested the banjo fittings from Pure Choice. We could have supplied a 1 in. bore cylinder with fittings on the other side but you would be standing on the pedal for all you are worth. I can assure you that using the original m/cyl. I have here from a 48 only moves the pedal over 1/4 inch relative to the mounting face that goes up against the chassis. The way you showed your measuring in the pictures you sent is not relative to the mounting surface.