I've recently purchased a '48 Ford Tudor that previous builder/owner has installed a Disc Brake front and running stock Drums in rear however I don't think they completed the job properly as it was running a stock Master Cylinder (that was actually empty when checked with some rusty sludge at the bottom of it) so was going to simply replace with a new Master Cylinder however after further reading it might not be the best idea and a dual reservoir Master Cylinder might be better. So who has upgraded their brakes with Discs at front on a '48 and what Master Cylinder have you used? Also, did you add a Brake Booster as well? Looking for advice before I proceed. **So, some updated information gathered today... ive taken some photos of the current Disc and Drum setup. Not 100% sure of the measurements needed but it looks as though the diameter of the rotor looks to be about 275mm to 280mm and the width of the disc about 25 / 26mm.
You will have to provide other information before anyone can give a solid answer. What are the front brakes from? If you don't know, can you measure the cylinder size and the disk size? The size of the stock rear brakes is unmodified, right?
look at the bore size, front and rear, then look at cars that use those sizes and see which master they use. Auto parts stores websites are good for this.
Ahhh....thanks guys (maybe not). Remember, this forum is for helping like-minded folks not for just sarcasm .... I'm pretty new to a vehicle of this age and don't know much about the history of this vehicle so just after advice and where to start so I don't have to keep experimenting to find out the wrong answers and cost me money and time. I'd rather try to sort out the proper equipment now so I can just dive in to fix the issue. So yes, I'm not aware of what they used for the Disc Brakes up front but at least Alchemy has given me a place to start, so thanks mate. I will look at that to have more information available. I also would have assumed that at some stage over the years someone else on here may have converted their early '41-'48 Ford to Discs at front with using the stock Drums on the rear and found a good setup for the best Master Cylinder setup. And has anyone added a Brake Booster, I've had some here suggest that it was strange that whomever set this up originally hadn't added a Brake Booster considering they were running Discs up front, not to mention why would they be only running a stock M/C with single reservoir seeing as how Discs and Drums don't run they same pressure. Thus the reason I'm reaching out for 'advice'. Thanks.
Take the pads out,and take them to a real auto parts store.Find the guy with gray hair,and ask him to ID them to a car.Once you know what car they came from you will be able to figure out caliper bore size.dont get to hung up on power brakes.Chevy pick up trucks well in to the 1980"s offered non power disc brakes.They stopped a 5,000 lb truck just fine.My 32 Ford pick up is non power disc,and it will put you through the windshield if im not careful.
Heads up: when asking about stuff like this it's a really good idea to post pictures of the parts in question. That way people will have an idea of what you are talking about and may be able to identify them, thus being able to provide educated answers.
Actually they were a little rough on you - they should have said "send us a picture of what you have " that always helps us or the HAMB guys - help fellow guys out. I see your avatar - is this the car - that will help with the weight question as well.
@motobassman About a decade ago I did a build on my (since sold) ‘47 Ford Coupe that included a disc brake conversion. I was using the stock under floor pedal assembly and did not want a booster, though I wanted very effective brakes. That lead me to install relatively large front discs/calipers and a modest master cylinder bore diameter to gain a favorable ‘hydraulic ratio’ with a small sacrifice in potential increased pedal travel. I chose a Speedway kit that used Ford pickup 12” rotors and big GM calipers (‘71/‘76 full size car and ‘80s era GM pickup). I added a ‘67/‘72 Ford Mustang disc/drum master cylinder. Installation included residual pressure valves front and rear but NO proportioning valve. Initially I kept the stock rear end and brakes but soon after I swapped to an open drive rear axle. That was an 8” Ford unit that had 10” x 1.75” brakes. Tires were 215/70-15 front and rear were 235/70-15. That combination resulted in a very satisfactory pedal pressure and very powerful stopping power and no rear brake lock up. Pedal travel was maybe 1/3 to reach very firm pressure. Ray
Yes, that would have been a much better response to my initial question, so thanks for saying so 'stillrunners' . I've just taken off the wheels today and taken some photos of the current Disc and Drum setup. And yes, its for the car on my Avatar.
We're helpful here on the HAMB, but we don't like to waste time. As a newby you got a very easy lesson today. "When asking a question, provide all the information." If you don't want to disassemble anything, the nice clear pic of the disc brake unit should find an answer. If you can see numbers on the caliper, that would be helpful too. If you can get a clear shot of the mounting bracket, you might even find out who made the kit. There are little adapters made that will let you mount a dual master right to the stock pedals. Then buy a nice pair of residual pressure valves from ECI (not the cheapo aluminum kind), bend some new lines to hook it up, and you will be stopping in no time.
I used a corvette inch and 1/8 master I believe ,front and rear disc without a booster in my model A. I got it from a friend,had it rebuilt it had some off brand parts inside ,the shop installed parts to standard. Car has 400 miles on it. I did put a proportion but never adjusted it.I installed a pedal kit under the floor,with some check valves not sure the ratio of the pedals but can check it in the am if needed?
Seems as if it's turned into, let's jump on, put down, chastise the new guy or previous asked question anymore.
Back when I did my 47 with power front discs I used a Lincoln or Mercury Versailles power brake booster and all and it was perfect.
The front discs definitely one of the aftermarket setups that the street rod shops sold using the aluminum hub. Most of those used the GM metric calipers 78-87 A&G body. I’d start there, pull a caliper and check the piston bore size. Earlier kits used 73-77 A&G body calipers.
My advice would be to remove and replace with a local brake conversion kit with locally available parts. Including the m/c, probably a disc/drum XB Falcon type at a guess. Try Rod-Tech in S.A.
The Jalopy Journal
