I'm looking for a 4 wheel disc brake MC that has less than a 1" bore....any ideas?

The ususal suspects - 1 ton trucks and vans, ford land yachts, 79 Firebird etc...all have 1" or 1-1/8" bore MC....too big for manual brakes

Willwood makes a couple nice units. I use one of their single chamber MC's with my manual 4 wheel disc setup. It is a 1" bore, but they make smaller ones.

What about the lincoln Versailles car?
A lot of the late 70's Caddilacs also had 4wheel disc.
I am also sure that the Nissan 300Z cars had 4 wheel disc and around a 7/8 bore M/C

As far as need ing a DISC brake M/C... just pop out the residual valve for the rear brakes... no big deal ( at least that's what I did on my old FJ 45 M/C.. so far no problems

Originally posted by BillaVista
I'm looking for a 4 wheel disc brake MC that has less than a 1" bore....any ideas?

The ususal suspects - 1 ton trucks and vans, ford land yachts, 79 Firebird etc...all have 1" or 1-1/8" bore MC....too big for manual brakes

Im runnin a 68 vette MC using manual 4 wheel discs dude. No problems. So are several others on this board.

What about the lincoln Versailles car?

1" or 1-1/8"

A lot of the late 70's Caddilacs also had 4wheel disc.

Again, 1" or 1-1/8"

I am also sure that the Nissan 300Z cars had 4 wheel disc and around a 7/8 bore M/C

Good tip....but man...you pay those "import" prices.....over $100 for a reman...over $200 new :eek:

Im runnin a 68 vette MC using manual 4 wheel discs dude

That would be the manual brake version? 1" bore I think? Hmmm...perhaps 1" is not so bad after all.

As far as need ing a DISC brake M/C... just pop out the residual valve for the rear brakes... no big deal

Depends on the MC in question....some have built in proportioning as well as residual valves, some both, some niether....and the big thing you're still missing is the larger resevoir....see, as the disc pads wear, the volume drop is substantially larger than with drum shoes wearing...that's the reason for the bigger disc resevoir in a disc / drum MC...not so the disc circuit can "push more volume" as so many think (though it's true discs require more volume....that's not really why the resevoir is bigger)

Yep Bill you're right its the 1" version with half ton fronts and small gm calipers in back oh and "domestic prices" ;)

From what I have researched...Chevy M/C's did not have the residual pressure valve in the m/c...it was in the prop valve. So, just about any Chevy m/c should work...I use a Chevy 3/4 ton truck for my 4 wheel disk...obviously, it is probably larger than 1" bore..but just offering info.

Not domestic....but....Toyota Supras....7/8" bore.

Jay

TTT :bounce:

you are a fabing super star go wilwood or howes with a balance bar and pick any bore size you want

me I would use the 1" and if I was too light to push the pedal either eat my wheaties or get a longer pedal/ move pivot point

i'm pretty sure my '72 wagoneer's mc is 1" bore, not sure if they changed bore in '74 when they added discs to the system.....

edit:

sorry, I replied too quickly... I thought you were looking for 1" bore, not smaller.

I have a 93 or something Toyota Landcruiser mc - 1" and the application had 4 wheel discs so it's pretty close for my setup. $45 delivered from a junkyard I found via car-parts.com ...

- jack

Some great info here guys, thanks much.

Mj - I though about a balance-bar setup, and a few other exotic ideas, but I'm really after dirt simple and reliable.

I think I'll go with the 68 Vette MC in 1" manual 4 wheel discs and get back in the gym! If that doesn't work...it's hydroboost time ;)

Teach me Bella......

What is the reason for the smaller bore with manual 4wdisk? JiMMy is running a Wilwood master, seems to work great for him, even with the big 60 caliper.

I am running the 79 bird master with hydroboost. Great brakes as long as my pump does not take a shit on me.

THE EFFECT OF PEDAL RATIO AND BORE SIZE ON HYDRAULIC PRESSURE OUTPUT
Pedal Ratio Bore Size lbs input PSI out
6:1 1 1/8 75 453
6:1 1 75 573
6:1 7/8 75 748

5:1 1 1/8 75 377
5:1 1 75 477
5:1 7/8 75 623

4:1 1 1/8 75 302
4:1 1 75 382
4:1 7/8 75 499

Assuming a pedal ratio of 5:1 - Note that going from a 1" to 7/8" MC bore increases the pressure to the calipers by almost 50% !!! So, this also means that if the 477 psi out with the original 1" bore was sufficient stopping power then the smaller bore would allow you to generate that same pressure with LESS lbs input...i.e. NOT SUCH A HARD PEDAL

Look here.

http://www.stockcarproducts.com/index.htm

I'm not sure of the bore... but I'm using a Master Cylinder for a 68 vette with manual brakes...68 had 4wheel disks with manual brakes standard and power brakes optional...
Works great on my 76 CJ-5 with 1 ton chevy brakes up front and 3/4 chevy disks in the rear..

Plus is was only like $35 or so from one of our local discount parts places (Advanced Auto)

Hey man... a 1976 - 1980 Chevy Monza used manual brakes, with a 7/8" bore. $14.25 from the parts place...

The 1980 Chevy Chevette used a 3/4" bore... The ones from A1 Cardone even come with the pedal rod... $13.75

A friend loaned me a Subaru M/C, which is 13/16", but has 4 outlets, so i have to find some plugs for it before I can try it out.

Any new news Billa Vista?

What about Volvo 240's? They have 4 wheel disks, and that old lady can accidentally lock 'em up pedal action.

Might be worth looking into.

Sean

I want to go to a domestic brake setup. THe Toy booster is the last Toy thing I have on my rig....

Can I run Manual brakes with my setup?

LT-1, 4L60E, Atlas 3.03, 4.88's, 42's?

Can I stop the sucker?

I am all for simple manual brakes, the corvette setup sounds nice....

Nolen, your sizing will depend more on the brakes you're running more than the running gear, although I know why you listed it...

methinks that the vette master with the 1" bore (made for manual brakes) will be the ticket.

I'm running Toy 4-piston calipers up front, and Monte Calipers in the rear, and going to try a 7/8" master... The unknown master I have in there now moves TOO much fluid (too big a bore), and therefore, I have a pedal which doesn't move much at all, and is very hard to press.

I'm all in agreement about domestic stuff... GM's don't have any valves in the MC to worry about, so a 4-wheel disc master isn't necessary, unless you're dead-set on having equal size res's. Since you're like me, and check it before every trip, and probably carry some fluid with ya, it isn't a big deal.

Point in case: I had a leaking fitting on my rear brakes, and was using them HARD all day on a trail run (lotsa hills), and still had plenty of fluid left when I topped it off.

Properly sized, a manual brake setup can stop nearly anything... even your heavy biotch... :flipoff2:

OK, I've learned alot from this thread (how'd that happen?!)


if a discs use more fluid, and most disc/drum MC's have two different sized res.. What about an older drum/drum master?? Equal sized resivoiurs, cheap, most were manual to begin with.....



would the strock possible not be enough?? Early ('72-74) Scout II's had a nice drum MC, not sure on the bore, but it *could* be a possibility.... have one sitting upstairs... maybe I'll go measure it..



any thoughts?

I went to www.discountautoparts.com , and when you bring up brake m/c's, it shows the bore size... the '86 S-10 is a 24mm... .94", which is larger than I want...

Last manual brake S-10 I drove a year ago had a really hard pedal, but that was probably neglect more than anything... :D

I'm going to do the '68 Vette MC when I get around to it....but it won't be for a while as the higher priorities include:

1) Get the trailer in shape for inspection (brakes? bearings?)

2) Tow rig needs new brakes, new gastank, new rad, and a hitch

I am working on a brake article right now to include all the good info, including residual pressure valves, metering valves, proportioning valves, combination valves, and even some hydraulic formulas for the really nerdy amongst us!!

Originally posted by mike


Im runnin a 68 vette MC using manual 4 wheel discs dude. No problems. So are several others on this board.


Will this MC work if you have a power brake booster?

I have a Scout with power brakes that I am converting to rear discs and am wondering what to do if my SII Disc/drum MC isn't enough.

When I had stock SII axles with 4wheel discs (F-150 calipers all around) the stock power drum/drum M/C worked great. The brakes were awesome.

Since I swapped to 3/4 ton axles with discs/drums the brakes have been scarier on hill desends than with 1/2 ton disc.

I'm ditching the rear drums on the 60 and going with 3/4 chevy discs and calipers on the rear. Any thoughts on the M/C...or the conversion? Thanks.

I Have a 4 wheel disk dodge stealth master sitting here, for 4 wheel disks. I have it on ebay right now.

Checkin the bore right now.

EDIT... just noticed the date... sure you already have a master cyl.
But for an FYI, the stealth master has a 1" bore.

Garrett

Bill,

GM used to list a 7/8" bore single circuit 63-66 Sting Ray MC (same as a 1 ton truck with large reservoir, for both semi-metallic drum and disc systems) and a racing version 7/8" dual circuit manual brake MC for the 67 Sting Ray. I believe all the 68 and later Stingray MC's are 1".

You might make a call to a good Mopar Performance dealer (anyone) as they used to list composite dual MC's in a variety of bores.

A good brake and machine shop can also sleeve a MC with a stainless steel insert to the bore of choice (possibly not technically DOT legal but for competition use...).

Any dual circuit tandem MC will likely work, and the fluid volume can be increased by piping a remote reservoir (tap and pipe the cover to feed fluid from a remote sump). The sump is at atmospheric pressure, so a moisture seal is all that is needed (too much trouble for most people, but common on European vehicles).

The dual MC's with balance bar parts can be found fairly easy. Fabbing your own dual MC system with the factory pre-67' single circuit MC's is inexpensive (just not lightweight and racy). The large volume reservoirs can easily feed large piston calipers, and isolated fluid circuits are fail safe. Most modern builders simply get out the Willwood or CNC products catalog (and the pocketbook).

I'll be looking forward to the techno-geek hydraulics section.

Happy Trails!

A bit late, but a Lincoln Versailles is F/R disc and uses a 15/16 bore master.

Bronco II's and Cherokees also use a 15/16 bore master, but aren't rear disc.

Billavista, how did your brakes turn out?

Ahhh, my brakes.....a bit of an ongoing saga.

Swapped in a hydroboost booster, with some success (TONS of boost) until i went full hydro steering, and then it appeared the booster was in fact faulty. Cut it out of the circuit to improve steering.

On the advice of Station, after having driven frankie's buggy - I am now planning on Wilwood dual 7/8" bore M/Cs with a balance bar. They're compact, relativly cheap, and provide great brake feel from what I hear.

celica, 15/16

I just installed a rear disc brake D60 in my bronco II(eldorodo calipers). Had 3/4 ton chev D44 junk up front. Since the brakes on my old rear axle were completely gone, I contributed the soft peddle to that. With the D60 installed, the brakes still sucked. Today I swapped out the 3/4ton front calipers for 1/2 ton front calipers and there wasn't much change. I'm not even sure the calipers have a different bore. There are some cosmetic differences, but my brakes felt about the same.

So, having a 15/16 bore master, I can lock up the rears, but not the fronts. Point being, while the smaller bore master can generate more PSI, it lacks the volume needed, resulting in too much peddle travel.

I don't understand how you are getting away with 7/8 bore masters and large calipers?????

Newer ford exploders have a 1 1/16 4 wheel disc master. I might give that a shot. Unfortunately it's metric.

BTW- your D44 disc coversion article doesn't have a link from the main tech page to the article itself.

All the Toy MC's are pretty much interchangable w/ each other from what I've seen. Available in 13/16, 7/8, 15/16, 1, and 1-1/16" on a whole bunch of different cars and trucks (1-1/16" is kinda hard to find though). And I don't think there is any difference in drum/drum, disk/drum, or disk/disk either. All or any special valving for the different ones is done outside the master...

Originally posted by Nobody
I don't understand how you are getting away with 7/8 bore masters and large calipers?????


I don't either. I ran a Toy 1" bore w/ my D44 front (large GM calipers) and stock toy rear drums and could put the pedal to the floor w/o locking up any tires...
Switched to a GM 1-1/4" and now the pedal is much higher and harder. I put in a dual diaphragm booster though and it works pretty well. :)
(I think a 1-1/8" MC would have been a better choice though).

I have a GM 1-1/4 master that I got with my 3/4 ton stuff. I was going to try it, but after reading this thread, I figured the peddle would be to hard like you say. I think 1-1/16 or 1- 1/8 is what I need.

edit: What's the dual diaphram booster from?

I have no probs with my 44/60 with the 15/16th toyota MC. I used the proportioning deal that was on the 4wheel disk celica..

Originally posted by Brandon
I have no probs with my 44/60 with the 15/16th toyota MC. I used the proportioning deal that was on the 4wheel disk celica..

What size tire......can you lock up all 4? How much peddle travel?