When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I am going to keep master cylinder under the cab. I am looking to stay with manual brakes but will upgrade front to disc. But for now because of lack of funds will stay with drum/drum. Is there a difference between the MC's for drum/drum and disc/drum? When I look at master cylinders in the catalogs they all seem to mention their MC's are for drum/drum and disc/drum and the all have what looks like a smaller front bowl. I thought this style was only for disc/drum. Sorry I am ignorant on this subject.
I don't know if there is or not. I do know that you want to get a master that has a divider built in to seperate the front and back. Also proportion valve when you go to disk on the front. I also believe that a disk brake bowl is bigger. It has to put enough fluid into the calipers without running out and the pistons are pretty big. Hope this helps
Anyone else have information to shed on this topic?
Yep, but it’s probably not what you want to hear. I think you kinda’ want now something that will work latter but it’s the other way around, make it for latter and use it now. What I mean is; (almost) all disc brakes use a vacuum booster (power) to get higher pressures with less pedal effort, especially important on floor mount in my experience, so your future disc upgrade will need a booster. Not sure, but I think the front bowel is for the rear brakes and vise versa (like backwards) the other thing is that floor mounts need pressure residual valves to keep some system pressure (long story) but stock master cylinders only have a valve on the drum side, normally disc don’t use them, but under floor do (mounted lower then caliper) so after market kits usually (?) have no valves and you install in-line as required (this is good thing for you).
So, if I haven’t confused both of us, what you do is install a floor mount with booster and front and rear 10 psi valves for drums and when you change over to disc you replace the front one with a 2 psi making sure there are no valves under in the master cylinder. (under the fitting seats). There is some debate that an extra valve is not serious as they are not accumulative but to **** Virgos like me, catastrophic!
<O But what do I know and as I say “being wrong keeps me humble”.
a disc/drum system does not require a booster, dodge ran a lot of these in the early 70's, as old F1 suggested a booster might be nice with through the floor pedals the light pressure needed with a booster is nice. My 70 duster has disc/drum with hanging pedals works great but you do need to lean on the pedal for a quick stop.
So Old F1 you are saying you cannot use disc brakes on the front with manual MC? If I remember correctly, I talked to a 54 F100 owner that had manual MC with discs on the front. He used the rsidual valves mentioned above
i'm looking at and adding to my parts wish list a disc drum combo that has a manual mc as the ol' flatty won't create enough vacuum i think . it has a proprtioning valve and inline residual valves 2lb. front and 10 rear , that should work fine with either a single or dual mc i'm told , but i want a dual . ran manual brakes with discs on all of the dirt track cars using oe parts all the time with no problems so ....................... the kit is from mid fifties . the disc's an the race cars just took a BIT more pedal pressure than what ya might think , but they worked . i want mine to stay manual everything as i found her to be the perfect vehicle as no one wants to borrow it because of the manual tranny , brakes , steering , and the cranky ol' flatty !!!!!!!!!!!!!!!!
So Old F1 you are saying you cannot use disc brakes on the front with manual MC?
No, if by manual master cylinder you just mean without a booster, (rather then a MC designed for drum brakes with built in valves), yes I think it would as long as it has enough volume/pressure, but it will take (a lot?) more foot pressure, enough to be annoying. Disc brakes are not self-energizing and take a lot of pressure to work.
So I am now totally confused on what to go to for brakes. I at least want to put a dual MC on for safety. I thought about going to power booster but then if the engine quits you have no brakes. Not sure if there would even be enough vacum. I am running a modern small block.
[quote=Pappys53;6855874]but then if the engine quits you have no brakes. quote]
No, you will still have brakes, power until the vacuum is used, and then manual, think of it this way, how many lets say 1970 thru 2000 small block cars and trucks with power brakes are there on the road? A couple of million!
the ultimate in brakes , and there are kits out there albeit pricey , is just like many of our 8-10 ton straight trucks have . electric over hydraulic four wheel discs . no need for a booster and you can prolly easily hide most of the components , and they work great !!!!!!!!! they just like power brakes also will work if something goes wrong just feel spongy and require a little more effort . take a look at 'em . if ya got the cash go for it .
I have a disk front and a drum rear on my 49. Master cyl. is under the floor, no power booster. The drum side has a 10 lb. residual valve built into the MC. I don't have one on the front. I put a proportioning valve on the rear to cut down on the rear brakes a little. I do have a metering valve on the front that delays the front discs from coming on until the rear brakes have kicked in. Everything works very well. I got my kit from ECI.
My kit was also purchased from ECI. I have disc/drum with dual MC under floor and no power booster on my '55. While it has been quite a while since I installed, I do remember ECI being very knowlegeable and helpful with my questions. Plus their MC mounting worked using the existing brake pedal and manual transmission.