power brakes to non power master?

[chevnut55]

my 72 camaro has a solid lifter cam so there is no vaccume,i have a electric pump that does not keep up to take it to a track day,i was told that i should switch to a non power wilwood small bore master and it will fell like i have power brakes.is this true if so what size master do i need?

[Apogee]

What brakes are you running? Factory 1972 disc/drum? If so, then a 1" bore master cylinder would probably be your best option as that was what was supplied from the factory on the manual brake equipped cars. Good pads, rotors, hoses and brake fluid will all help your cause to varying degrees.

For the master cylinder, whether you go Wilwood, OE, or some other aftermarket/OE option is up to you as hydraulically they should all perform the same riven the same bore sizes. Manual brakes do not feel like power brakes, but that's not necessarily a bad thing. Manual brakes will typically require more pedal effort, however in return you will get more feedback and have better braking control.

Tobin
KORE3

[Vegas69]

I agree Tobin. They feel NOTHING alike. I prefer power brakes on the street and manual on the race track. Manual brings in more pedal travel naturally and an increase in brake pad knock back.

[chevnut55]

thanks. it has 4 wheel disc,a bit larger than stock and a wilwood prop valve mounted under the seat. i do not like the vaccume motor im using ,its loud runs out of vaccume ,and it quit on my once in a high speed panic stop.i was told to use a wilwood 7/8 bore and it would stop as good and easy. i dont mind not having the power brake feel as long as it it easy to stop. it is a 600+ hp car with a 5 speed,i want to take it to the track soon but not with that electric pump,hiting a wall to stop will not be fun.

[Vegas69]

I've been running a 7/8 bore for about 4000 miles and 8-10 races. I just switched over to a 1 inch bore to help with pad knockback but don't have any driving or racing observation just yet. I'll try to remember to get back to you.

[silver69camaro]

I've been running a 7/8 bore for about 4000 miles and 8-10 races. I just switched over to a 1 inch bore to help with pad knockback but don't have any driving or racing observation just yet. I'll try to remember to get back to you.

Are you having knockback problems in the rear brakes? I just got done solving my issue earlier this year.

[Payton King]

but Matt, how did you solve that problem?

[Vegas69]

I'm with Payton, please share..... It's out back mostly.

[silver69camaro]

I'll start a new thread.

Edit: What axles do you guys use? Pressed-on bearing or c-clip?

[Vegas69]

Mine are press on tapered 33 spline moser axles with big ford ends. 12 bolt housing.

[silver69camaro]

Sounds good, I'll get a new thread going today sometime.

[chevnut55]

so what is the difference if i go with a 7/8 borecompared to a 1"? and will i need to get any other parts to install the new wilwood master? i wish i had built the motor a little less with a hydro cam,i want to swap it over to the f.a.s.t. efi that looks like a carb,but they say it will not work with no vaccume.

[silver69camaro]

Well, a 1" bore will require more pedal effort. I don't know what calipers you are using; if Wilwood, try 7/8", if OEM try 1".

My opinion anyway.

[Apogee]

so what is the difference if i go with a 7/8 borecompared to a 1"? and will i need to get any other parts to install the new wilwood master? i wish i had built the motor a little less with a hydro cam,i want to swap it over to the f.a.s.t. efi that looks like a carb,but they say it will not work with no vaccume.

Like Matt pointed out, you really need to let us know what calipers you're running front and rear since that is the single biggest determining factor in sizing a master cylinder. Tell us the application they came from, the piston size...snap a picture and post it up and someone should be able to recognize it. Anything.

Tobin
KORE3

[chevnut55]

it has stock 79 camaro calipers . the rotors are drilled and slotted and it has a adjustable prop valve. the brakes work great ,just have the vaccuume problem.

[woody80z28]

it has stock 79 camaro calipers . the rotors are drilled and slotted and it has a adjustable prop valve. the brakes work great ,just have the vaccuume problem.
Those huge front calipers make a manual brake application tricky. What about the rear calipers, what are they?

I went to a Wilwood caliper with a smaller piston to try and help with my pedal travel issue. It helped, but I'm still not really happy with it yet.

I'm wondering if knock-back could be part of the issue.

[Apogee]

it has stock 79 camaro calipers . the rotors are drilled and slotted and it has a adjustable prop valve. the brakes work great ,just have the vaccuume problem.

The factory '79 Camaro 4-wheel disc application used 2-15/16" pistons up front and 2-1/2" pistons in the rear calipers. Your best bet would be a 1" bore master cylinder for those calipers in a manual brake configuration. Too small on the MC and the pedal will be on the floor in a panic stop situation.

Tobin
KORE3

[chevnut55]

good,ill order a new master from summit,thanks.

[woody80z28]

The factory '79 Camaro 4-wheel disc application used 2-15/16" pistons up front and 2-1/2" pistons in the rear calipers. Your best bet would be a 1" bore master cylinder for those calipers in a manual brake configuration. Too small on the MC and the pedal will be on the floor in a panic stop situation.

Tobin
KORE3

There is no factory Camaro 4-wheel disc application. However lots of people convert to the stock T/A applicationthat did have a 2-1/2 or 2-3/8 piston. I can't remember exactly what the size was.

[chevnut55]

i swaped it over to a 1" willwood master. i lost 30 lbs off my front end..thats good. but it stops like a turd,i hate it. the pedal seems to work fine not too hard not to soft,but it does not want to stop so good..like it does not have enough pressure.i know its a different feel from power brakes and it started out as a manual brake car stock and it stoped faster. i know everyone is going to say bleed the brakes ,but i did it 20 times and went through 3 cans of fluid. any other tricks?

[Apogee]

Thanks for the correction Woody80z28...I should have said F-body, not Camaro. And just to confirm my previous statement, the "451" rear caliper castings use 2.5" diameter pistons.

Back to the topic at hand, I have two questions for you chevnut55. First, are you running the MC in the manual configuration with respect to the pedal and the pushrod? The pedal ratio on the 2nd-gens is a little less than the first-gens, but should still be around 5.7:1 for a manual brake installation.

Next, did you bench bleed the master cylinder and confirm that it was fully bleed by plugging the outlet ports and making sure that it hydraulically locks after about 1/8" of stroke give or take? If there's air in the MC, it will still be a bit spongy with the ports plugged. You can push 55 gallons of fluid through some systems and they will still have air in them, so while more is sometimes better, technique counts for something as well.

Now for the bonus question, are we correct to assume that your rear brakes were functioning properly prior to the new MC? Those calipers can be somewhat difficult to get set up properly at times, so if they were just added to the system, that would be good to know as well.

Tobin
KORE3

[chevnut55]

on my camaro it has a spot on the lever for power or manual so i put it back in to non power location. the rear brakes are from a kit using 80s mid size cars,its the same as the 2nd gen t/a but with easy e brakes. i did bench bleed it however the kit from auto zone was carp and it kept falling out and leaking fluid,i did it but even after it was clear i could see some air in the tubes. i blead them again and see no air at all but its still the same,it does work it i pump it 5 times before i stop so it does sound like air in the system. is should i crack open the lines at the master?

[Apogee]

You could try cracking the fittings at the master cylinder, however that typically only removes the air induced into the system from connecting the hard lines, not the small trapped bubbles inside the master cylinder. IMO, you should verify that the master cylinder is fully bleed per my previous post. If you plug the outlet ports and the piston does not hydraulically lock almost immediately, then it needs to be bench bleed again. In my experience, trying to do it on the car is not worth the few minutes it takes to pull it from the firewall and do it right in a vice. The ability to tilt the MC and tap on it with a mallet while stroking the pistons is worth a lot and should reduce the amount of time ultimately needed to complete the bleeding process.

Tobin
KORE3