what m/c to use

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J

jerry's demon

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have a leaky m/c on my 72 demon. car is 340/727, man disc brakes. the m/c
i'm taking off has big & small reservoirs. put a small/small res. on. which parts
store gave me. brakes don't seem to work as well. need 4 bolt pattern m/c.
can i upgrade to diff year? they ordered a 3rd m/c today. have tomorrow.
any suggs.? don't want to modify parts. thanks.
jerry
 
You need the big and small resevoirs m/c if you have disks on front and drums on the rear. The big resevoir is for the rear drums.
 
Actually the big resevoir is for the discs, because of the piston area of the calipers they need more fluid.

Chuck
 
I went through the problem of getting the correct M/C for my Cuda a couple yrs. ago. The first one I got was the small/small resovoir one like you got and it didn't work well. Then I got one for a 74 Dart with disc brakes. It was the style with the big resovoir in the rear. The first 2 I got were rebuilt and not very good. Actually IMO they were junk. After I looked online at Napa's website I found a brand new one they could get for just $15 more. I ordered it and had it in 2 days and since it's brand new it works great. Sorry I don't remember the part # anymore but just go to www.napaonline.com and put in 74 Dart with disc brakes and it will come up with different M/Cyls. to choose from. Then you can take that number down to your local Napa and order it.
 
Personally, it sounds like a perfect time to change over to the new aluminum master cylinder. Unless you're looking for a 100 point restoration, you'd be hard pressed to do better, performance wise than the new one. Besides, in 20 years which m/c will be available when you need a new one? very simple to do. Even seen a kit on ebay with the m/c, adaptor, and rubber locking ring for around $70. I put one on my duster and am glad that I did.
 
Anybody have tips on that Master cylinder swap?
4 -2 bolt conversion?
 
I did it a couple of years ago on my Duster. I picked up one of those 4 to 2 bolt adapters from MagnumHP (this one: http://www.magnumhp.com/showdetails.php?ITEM=are-02) and an aluminum master from AutoZone - the one right near you in Centeroach. I'm pretty sure it was for a D100. I've got factory drums in the back with Wilwood discs in the front - manual.

MAKE SURE you get a MC that is machined for the pushrod retainer!
 
thanks guys, for your responses. if i can't find something to work now, its
cause they don't make it. this morning, my parts guy called and found me
a 73/74 dart man. disc brk. m/c. i will try once more, and if not i have info
to use to fix problem. thanks again.
jerry
 
rumblefish360 said:
Mike, thanks man! What is this exactly?
Click to expand...
There's a rubber piece that goes on the end of the pushrod. The MC has to be machined to accept this piece... otherwise your pushrod will just be sitting inside the bore with nothing to prevent it from popping back out. The rubber piece (like a grommet, I guess) fits in there and prevents the pushrod from pulling out.
 
Here is pic of the alum MC.I installed the Mopar heat shield for ***** and giggles.There is a guy on ebay selling the complete kit with a brand new MC + the adapter for $100.00.That is were I got mine.The heat shield was from the dodge dealer,part #P4510634.

Picture 397.jpg
 
mikelbeck said:
There's a rubber piece that goes on the end of the pushrod. The MC has to be machined to accept this piece... otherwise your pushrod will just be sitting inside the bore with nothing to prevent it from popping back out. The rubber piece (like a grommet, I guess) fits in there and prevents the pushrod from pulling out.
Click to expand...
WOW! The rod can pop out?!?!? That's a scary thought.
Do you have a part number to the proper MC?

Johnny Dart. Thanks. Have a link to the guy's e-bay listings?
 
rumblefish360 said:
WOW! The rod can pop out?!?!? That's a scary thought.
Do you have a part number to the proper MC?

Johnny Dart. Thanks. Have a link to the guy's e-bay listings?
Click to expand...
Well, yeah, if there's nothing holding it in the MC it can just pop right out. Have you ever pulled out a MC and had to remove the pushrod? That thing gets jammed in there pretty good when the retainer is used.

I don't have the part number, I went to AutoZone and asked for an aluminum MC for a D100 truck. They pulled out a couple, I checked the back to make sure it had a little recess inside of where the pushrod goes (for the retainer) and got one for around $50. New, not reman, and from AutoZone it comes with a lifetime warranty. Make sure that there's a retainer in the box, too. It's a small ring... here's a pic:

27.jpg


I found that MagnumHP has the MC: http://www.magnumhp.com/showdetails.php?ITEM=MAG-1

Actually they have everything you'll need:

http://www.magnumhp.com/brakes.php

MC, adapter, pushrod retainer, Greg (the owner) is a real good guy, he used to live out east before moving down to FL.
 
I bought a MC w/Adapter from Rick off moparts, and retainers from MagnumHP. Seems good, machined for the retainer. I went from factory power brakes, to a manual setup with this m/c. Just used a factory ebody push rod for a manual car. Just make sure, if you have manual brakes, bigger the bore, harder the pedal. It does take some getting used to (pedal stiffness). I also have 11 3/4" front Cordoba discs.

000_0028.jpg
 
Mike, that picture is the bomb. Now THAT'S what I'm talking about. I didn't ever notice that lil'part in the rear of the M/C. Greag has'em huh? I remember when Greg was out here. It's been a while now hasn't it?
Thanks.

Goody, thanks dude. This is for my Duster project. I'm going from 4 wheel Power drums @ 9 inchs I think they were (?) to 11 inch rear drums and the same ('78) Cordoba 11-3/4 discs.

Power booster problems around the corner for me?
 
yeah and they're like $2 bucks each! make one out of 1/4" fuel hose and make the little V in on the bench grinder. it will cost WAY LESS. the alum mc comes in either 15/16" bore(more pedal effort, less travel) or 1 1/32" bore(less pedal effort, more travel). i also have the alum mc, cordoba 11 3/4" discs, and she stops really good.

sorry, can't find my pics right now.
 
I bought my MC at Autozone also. IIRC, the new one was cheaper than a rebuilt one. If you buy rebuilt, you have to either have the plastic reservoir or buy one. Buying one was where the rebuilt became more expensive. Even if I did have the reservoir, I would opt for new over rebuilt and it wasn't that much more of a rice difference and no core.
 
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