1962 ford brakes
- Thread starter melisa
- Start date
scicala
Well-known member
There may be evidence of a vacuum hose for the brake booster from the intake manifold/carb, or the brake pedal rubber pad (if original) should say "power brakes" on it. I don't think there was any difference between power and manual brakes on the actual brakes at the wheels. Just the addition of the vacuum booster and maybe a different master cylinder for power brakes.
Sal
Sal
frank long island
Well-known member
with a big car and drum brakes I would opt for the power brakes
Motorhead6
Senior Member
Since you are going to buy a MC anyway, great time to opt for a dual MC. You will have to add a proportioning valve and do some re-plumbing, but nothing major.
Alaska Jim
Well-known member
I do not believe A proportioning valve is needed if the car has drum brakes on all 4 corners.
JeffB2
Well-known member
This will apply to your '62 and you can use the exact same parts listed. https://www.youtube.com/watch?v=wXfXKlj2D1I As been stated previously do not use the teflon tape.
bobss396
Well-known member
The biggest take-away from this is keeping the rod length the same on the new master. Will save a lot of grief from getting boxed into a corner setting it wrong.
Motorhead6
Senior Member
True, but a proportioning valve adds the safety of blocking off the flow of fluid to a leaking wheel cylinder in the event of a failure. If the MC has dual fluid chambers (not all do) this may not be an issue; not sure. I only point this out because there was a retired Ford engineer on here a while back that asserted that a proportioning valve was designed to perform this function. Many Barners disagreed, but I tended to believe the guy that actually designed the part.
Also, the drum brake MC has an internal residual pressure feature. Not sure that a dual MC has this feature but I believe the proportioning valve provides this. Maybe an expert in this matter can clarify this issue.
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bobss396
Well-known member
Some dual masters have built in residuals. I don't add then until I know I need them. Most cars with masters up on the firewall don't need them.
I used an SSBC proportioning valve on my '59. Using the stock brass block was ugly with the lines I had to make up and the SSBC item made it easier for me.
http://www.summitracing.com/parts/ssb-a0730?seid=srese1&gclid=CPe11Puy68wCFYNkhgod5PEEYQ
I used an SSBC proportioning valve on my '59. Using the stock brass block was ugly with the lines I had to make up and the SSBC item made it easier for me.
http://www.summitracing.com/parts/ssb-a0730?seid=srese1&gclid=CPe11Puy68wCFYNkhgod5PEEYQ
V8 Bob
Well-known member
It is possible some early pressure differential valves (not proportioning, but part of a combination valve, that might include proportioning) blocked off the low pressure system, but I've never seen one in the many years I worked with and dynamically tested them, mainly on Fords. And I've seen a Ford engineer write up stating that's how the one my company made and sold to Ford worked, but was incorrect. It can be easy to think that's how they may work when looking at a cutaway picture or drawing. But why would you want to loose some available braking because of low pressure? The switches generally triggered around a 400 psi pri./sec. differential, not a complete pressure loss.
Their main purpose was turn on a dash brake warning light.
All (that I know of) single and dual master cylinders intended for drum brakes had internal residual valves up until the '70s, regardless of master location, because the older drum brakes needed them. It is possible some proportioning valves contained a residual, but I've never seen or heard of one.
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Motorhead6
Senior Member
V8 Bob Thanks for the clarification; it explains a lot. I guess the combination valve you refer to is pretty much what we laymen incorrectly call a proportioning valve but with additional function.
I found the following on a CPP web site. This explains the issue a bit further in a system that has disc front and drum rear wherein the return springs of the rear brakes will override initial application of brake pressure and thus momentarily delay stopping force of the rear brakes. This would compensates for the lack of residual pressure when initially applying brakes; probably where the confusion of a residual feature of the proportioning valve has its genesis. I guess it would be true of a drum/drum system as well?
"The Proportioning valve does not allow any pressure to the disc brakes (front) until a pre-determined pressure has been reached. The pre-determined pressure is low when compared to the maximum pressure in the braking system, this allows the drum brakes (rear) to engage before the disc brakes engage. Having the rear brakes engage first provides the control and stability needed to stop your vehicle safety."
Would you not agree that a combination/proportioning valve is a necessary item when going to a dual MC set up? If not, what keeps the MC from emptying the reservoir in a unit the has one reservoir for both front and rear systems?
Please understand that I am not being obstinate here but am trying to pick your brain to better understand the whole schema of the braking system. I am in process of putting a dual power brake unit on a drum/drum system and want to keep is as simple as possible while making it safe. The kit I bought includes a "proportioning" valve. I guess the correct nomenclature is combination valve, eh?
I found the following on a CPP web site. This explains the issue a bit further in a system that has disc front and drum rear wherein the return springs of the rear brakes will override initial application of brake pressure and thus momentarily delay stopping force of the rear brakes. This would compensates for the lack of residual pressure when initially applying brakes; probably where the confusion of a residual feature of the proportioning valve has its genesis. I guess it would be true of a drum/drum system as well?
"The Proportioning valve does not allow any pressure to the disc brakes (front) until a pre-determined pressure has been reached. The pre-determined pressure is low when compared to the maximum pressure in the braking system, this allows the drum brakes (rear) to engage before the disc brakes engage. Having the rear brakes engage first provides the control and stability needed to stop your vehicle safety."
Would you not agree that a combination/proportioning valve is a necessary item when going to a dual MC set up? If not, what keeps the MC from emptying the reservoir in a unit the has one reservoir for both front and rear systems?
Please understand that I am not being obstinate here but am trying to pick your brain to better understand the whole schema of the braking system. I am in process of putting a dual power brake unit on a drum/drum system and want to keep is as simple as possible while making it safe. The kit I bought includes a "proportioning" valve. I guess the correct nomenclature is combination valve, eh?
V8 Bob
Well-known member
The info you found on the CCP web is, sadly, common among some brake suppliers, who do not understand some of the products they sell, and is one reason these brake related posts and questions resurface.
A picture of what you bought would be helpful, but if you are not installing a brake warning light, all you may want or need is a simple distribution block.
Motorhead6
Senior Member
V8 Bob
Thanks for the clarification. Will proceed accordingly.
Thanks for the clarification. Will proceed accordingly.
bobss396
Well-known member
A stock brass block will work. This is why I like to use older donor parts, before the onset of more complicated brake plumbing.
Your Ford has one somewhere close to the engine crossmember. An "in" from the master, 1 "out" to the rear and 2 "outs" to the front.
Run the rear brake line right to the rear port on the master. Cap off the rear port on the brass block. Run the front master line to the original "in" position on the brass block. The front "outs" can remain as is.
Your Ford has one somewhere close to the engine crossmember. An "in" from the master, 1 "out" to the rear and 2 "outs" to the front.
Run the rear brake line right to the rear port on the master. Cap off the rear port on the brass block. Run the front master line to the original "in" position on the brass block. The front "outs" can remain as is.
V8 Bob
Well-known member
You have to be careful here, because not all dual master cylinders have the rear axle plumbed to the rear, or primary port. It's very important to know how the master being used was designed to be plumbed, because rarely are the primary and secondary piston strokes equal in fluid displacement, even if the reservoirs look the same.
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Alaska Jim
Well-known member
V8 BoB is correct, many master cylinders use the rear reservoir for the front brakes. I think that in a brake drum/disc system you will find that the larger of the reservoir's will be for the front disc caliper, as they require more fluid to actuate than a wheel cyl. . not sure how to tell which would be front or rear in a drum/ drum system.