How Do I Choose a Master Cylinder?

So like the title says, how do I go about choosing a brake master cylinder?

It will be manual brakes so no booster. It is setup as a 2000lb vehicle, with 8" discs in the front and 9" drums in the rear (already has the proportionin valve built into, so it has a common input for the brake line.

My internet research says 1" or smaller for non power brakes, but aside from that what other factors should come into play?

And like all things grassroots I'm looking for a cheap but quality option.

miata?

There was an article about this on this a bit ago..... Stupid brain fog.

Lol, no not a Miata. Its actually for a Jacobsen UTV, heavily modified of course.

AngryCorvair is the man to ask about this one. He will need to know: wheel cylinder bore size, caliper bore size and the number of caliper pistons.

If I read your description correctly, you need only a single line from the master cylinder? If so, Tilton has all kinds of stuff reasonably priced. If you need a dual line cylinder, I have bought new ones from Rock Auto for $35.00. The trick to that is to know which cars have the bore size you need, since Rock Auto doesn't list by bore diameter.

I measured the old one and it looks to be a 1" bore. I'd easily replace it except I have no idea of the brand (says Made in USA 1051) and the rubber boot on the pushrod says Warner and is solid cast iron i believe)

It has a three bolt flange on it wich I can't seem to find anywhere.

three bolt flange is / was common with single units. Try Inernational loadstar 1700 truck mid 70's

44

The depth of knowledge here is insane. International Loadstar mid 70"s?

Wow. 44's knowledge of esoteric stuff is WAY better than mine. Three bolt stuff was common on forklifts too. Any reason you can't make an adapter plate and use a 2 bolt unit?

Long shot; if you can't find a replacement unit White Post Restorations can sleeve a master cylinder. Warning: I have no first hand knowledge and I have heard both fantastic and horror stories about them. http://www.whitepost.com/

In reply to Jensenman:

I think I will just do that, looks like a Mopar 4 bolt adapter will work. Just need to get a resiviour big enough for the brakes.

Lots of stuff ~Here~

Bore diameters listed.

I had to rebuild the one on the local dirt tracks water truck a few years back, it was three bolt. Seal kit was ~$20. Unfortunately no one had it in stock we ended up buying another 1 inch bore kit and just using the cup seal and a quick hone job. It's still working in-fact I'm headed over their now to roll the track in.

44

I'm thinking that the 4 to 2 bolt conversion will work (top two holes are 2.25" apart like Mopar.

All of the 2 bolt MCs in that pattern are for a tandem/dual line setup. Can I use one of these MCs and just block of the unused port?

I'm going to go out on a limb and say no, blocking off a port in a dual circuit cylinder won't work.

These have a vertical 2 bolt pattern. That might be easily adapted to your setup.

http://www.tiltonracing.com/content.php?page=list2&id=21&m=b

You might also look at master cylinders for early 1960s Fords. Like this:

That's a 7/8" bore cylinder for a 1964 Ford Falcon. A 1964 F100 master cylinder looks just like it and has a 1" bore, Rock Auto has that one listed as a Dorman M37781 for $45.79. Looks like it's a new one.

I called Wilwood for some advice,very nice, helpful folks. I ended up with 3/4 front, 7/8 rear with 6:1 pedals on my 2100lb E30 and they were dead on. Modulation is good and I only have to adjust the balance bar and rear pressure relief a little bit for track conditions to dial it in.

Can I run a tandem master cylinder in parallel, just combining the two outlets into the 1 existing brake line, so that later if I want/need to I can separate the front and rear brakes?

Paging Angry Corvair...

Stoptech's website has tons of great articles on braking. I just finished designing the braking system for a FSAE car and those articles were great.

i would not run all four wheels off one single circuit, because a leak anywhere in the system means all four wheels have no brakes. that doesn't end well.

post pix of your existing MC, please.

Here are pics of the current master cylinder. Its a single out design. Front brakes are 8 inch discs, and rears are 8.9 inch drums on a dana 44.

Yup looks like most older clutch and brake masters you see on pre 67 stuff.

need to know the diameters of the caliper pistons and the diameters of the wheel cylinders.