Hey guys is there something wrong with using this? Some people are telling me that they are dangerous and that I will forever have to be adjusting it, true or not? Im using 63-67 econoline drums and spindles up front and 8.8 ford rear end with drum brakes as well. Im using this pedal****embly and have theses as well x2 Please help me, the last thing I want to do is kill myself.
I hope it works cuz that's what I have on my disc/drum setup on the A. Back to Shifty's question...there is a difference in the disc/drum and drum/drum setup but I can't remember what it was and I'm at work on lunch break so I don't have my notes. Anyone?
with drum/drum brakes you should not need a proportioning valve. the master cylinder in the picture is a disc/drum...i'd use a drum/drum one make sure both of your residual valves are 10 psi who is telling you this stuff is dangerous?
When I called speedway they told me that you can use that master cylinder for dic/drum or drum/drum. Both of my residual valves are 10psi. Why dont you need a proportioning valve on a drum/drum set-up? One of my buddies who is helping build the car says it dangerous. Somebody help cause I dont have a clue and I dont want to kill myself in this car.
i'm sure it will be fine , but i'd still use a drum/drum master cylinder proportioning valves are use in disc/drum to reduce the pressure to the rear drums because disc need more pressure..i'm sure you will be fine without one with drum/drum
I have two cars with these installed on the brakes. Both have very similar braking and tire setups: discs up front, drums in the rear. Both have very skinny tires up front and big 10" tires in the rear (slicks on one and cheaters on the other). One is raced and one is street driven. Now when I plumbed both systems I included one of these for the rear brakes. I left them set at the midway point and then figured that I would adjust once I saw how the braking went. Well I never had to touch them. I DID play with the one on the drag car a little but I was never able to discern any stopping difference so I left it alone. -Scott
did your friend give you any reason why it would kill you? things are easy to say if you dont have to back them up with proof. I agree with what 36-3 window is saying .. drum/drum run a drum drum M/C.. Disk /Drum run the proper system for that set up. if you dont mix up the components, and try to make them play well togeather .You shouldnt have any issues.
Well speedway said that you are able to use that mc for app's drum/drum or drum/disc, so if I used all those components that are shown in the above pics it should work fine right? What he said was that he had heard stories of the APV losening and lock the fronts up and guys losing total control.
I was going to place an order today for the same stuff. GREAT Timing on your post. I was told the same from the tech support guys about the MC. What are you going to do now?
Well I have all this stuff in the garage at home and im just hoping that someone will be able to tell me that this will all work as planned, cause im not sending this stuff back from canada to the states it's too much of a hassle. I going to wait patiently cause I know that one of our fellow hambers will be able to give me the green light.
Don't be fooled just because one reservour is smaller than the other. That does not mean its a disk/drum MC. There are plenty of drum/drum just like this. Many Ford MC's I know are this way. Its the bore diameter that matters and it will be different for power or manual.
Maybe the entire subject needs a little review? First, the master cylinder: There ARE differences between disc/drum and drum/drum master cylinders. First, and most obvious, is that a disc/drum M/C has different chamber volumes (because a calipers piston chamber is larger than the average drum brake wheel cylinder). In simple terms, provided the M/C piston is a consistent diameter, there are no ill effects from the different chamber sizes. The other difference, which IS of interest...it is pretty common for master cylinders to have integral check valves installed in the outlets. ****uming this is true, and depending on the application, that disc/drum M/C would (typically) have a 2psi check valve in the disc chamber outlet, and a 10 psi check valve in the drum outlet. So...what you need to do, at a minimum, is check with Speedway and determine if that particular M/C has integral check valves. Obviously, you don't need a brake system with redundant check valves. And you don't "need" check valves unless the M/C is below the elevation of the wheel cylinders. So, before you purchase, ascertain the configuration of the M/C you are purchasing. Regarding the proportioning valve...I prefer to run one only because I believe that the potential variables that affect braking performance....weight bias, different tire diameters (well, actually, the tire radius) suggest that you have the ability to tune the system. But in reality? On a drum/drum car? My opinion is that it's not necessary. Let me reiterate one thing, though...there is a reason that four-wheel drum brake components are different than two-wheel disc/two-wheel drum components. Personally, I would always resist the temptation to make a choice because the "Speedway guy" (and I buy stuff from them, so I am not dissing them, per se) said it would work. It is your responsibility to educate yourself as to the attributes, mechanically and performance-wise, of ANY component you put on your car. My $.02
Just got of the phone w speedway and that master cylinder does not have integral check valves so i was right to purchase the two 10psi rpv's and speedway said that you dont have to put an apv on a drum/drum set-up but it wont hurt it at all if you do.
DallaBill, Very well put! In my call to the Speedway guy he said as long as I made sure to use the 10psi residual valves for drum/drum and 2psi/10psi for disc/drum then it would work. Is there a defference between the "check valve" in the chamber and one added into the line?
Minchione, what are you doing for plumbing these breaks? It seems your build is a half step ahead of mine on breaks. I'm still trying to pick fro 37deg and 45deg double flare, 20 feet of line "kit" or straight sticks from the parts store down the road. Thanks
So if no porportioning valve is needed on a drum/drum set up, what in the system controls the front/rear brake pressures?
On Flower's car we have '40 front drums and stock Ford rear drums that came on the 8" diff. with a single early Mustang master. We use a 10 lb residual valve and no proportioning valve. The flatty roadster has a great pedal, nice pedal "feel" and stops GREAT. Some bonehead pulled out in front of her one evening coming back from Bob's Big Boy and she had to really hammer the brakes........I'll tell you, not many later model cars could have stopped that quick and controlled. I use only a 45' double flare on brakes.
29Jay find a local FLAPs that sells Inperial they should have 25 ' rolls of brake tube and flare nuts. Rocket Hot Rod : Answer here is nothing, because as long as both pistons in a dual bore M/C are the same size you will have the same outlet pressure.Result is the same for all intents as a single master. Braking force ballance in a stock vehicle is done by varying the wheel cylinder bores. IE. the rears are usually smaller,and/or the brake it's self may be smaller.
JohnEvans, thanks for the explaination. It explains my brake set-up: Front: 12" Drum with 1.0"/1.375" bore cylinders Rear: 11" Drum with 1.0" bore cylinders MC: Same as minchione's picture in this thread with 1.0" bore 10psi residual pressure valves/no porportioning valve. Still dialing in the brake system but it works very well.
I love this place! ! ! Where else can you find guys doing the same thing as you and find another group that has done it already... Thanks for this thread!!!
Any way to know if the M/C has internal RPVs other than checking with the supplier / manufacturer? Pete
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