Just saw a thread that mentioned an EM with a remote power brake booster in the trunk. Very intriguing so I checked into it further. They are still available at: [www.mpbrakes.com]

They are pricey at $750 but it seems like it might be a great solution for Corvair people who want power brakes. You can download the instructions which specify that you can either use engine vacuum or an electric vacuum pump. Where do you think possible mounting locations would be?

What do you think?

Dan
Chandler, AZ
1966 Corsa Turbo Convertible
[corvaircenter.com]



Edited 1 time(s). Last edit at 10/14/2016 02:13AM by Dan.

Says only for disc brakes. Is that due to check valves?

I think I would prefer to custom fit a power MC like in this V8 Vair.

Dave W. / Gilbert Arizona
65 Corsa 140/4 Butternut Yellow
66 Corsa 140/4 Stinger Tribute
66 Corsa 140/4 w/factory A/C Aztec Bronze
65 Monza Convertible 110/4 Hunter Green
65 Monza 4DR 140/PG w/factory A/C Ermine White
65 Monza 4DR EJ20T/5 Light Mettalic Blue

Dave, they have 2 models. One for disc/drum and one for disc/disc.

Dan
Chandler, AZ
1966 Corsa Turbo Convertible
[corvaircenter.com]

Dan Wrote:
-------------------------------------------------------
> Dave, they have 2 models. One for disc/drum and
> one for disc/disc.

Gotcha. The only place I would mount one of those is back up under the rear axle where the heater box lives.

I don't like looking at the A/C evap box and fan in the LM trunk, let alone a rig like that. When I first saw it I thought it looked like a rerally huge add-on cruise control box circa 1970.

Dave W. / Gilbert Arizona
65 Corsa 140/4 Butternut Yellow
66 Corsa 140/4 Stinger Tribute
66 Corsa 140/4 w/factory A/C Aztec Bronze
65 Monza Convertible 110/4 Hunter Green
65 Monza 4DR 140/PG w/factory A/C Ermine White
65 Monza 4DR EJ20T/5 Light Mettalic Blue

I guess each person has their own taste, but I hate the feel of power brakes, even though most of the cars I've owned have had them. When I had my Corvair with the normal master cylinder setup, it just felt so much better knowing I was going to stop with the pedal only traveling a couple of inches. Even on my 2014 Camaro SS, I had an emergency stopping situation when the pickup in front of me decided to not go through a yellow traffic light. When I hit the brakes, it felt like the pedal went all the way to the floor board. I did stop in time, but still, that feeling is kind of unnerving.


Tom
DFW, TX

I took a look at the MP website. The one Phil has shown above is the disc/disc unit. It has two boosters and two slave units. The disc/drum that they sell is a single booster and single slave that provides boost to the front disc brakes only. The rear drum brakes are un-boosted.

That is one hokey setup.
The dual unit is just two identical single units back to back.

The '64 that was mentioned is using a single master and single booster to boost front and rear.

I looked into this many decades ago. A single remote booster (popular brand then was hydrovac) is sufficient if you have a single brake circuit as was stock on earlies. With a dual master, you need two remotes--disc or drum.

That stopped me, as I have fitted a late 2-circuit master. Doe anyone know if there is a conventional vacuum booster/MC that will fit an early? Space is very limited. The diameter constraint would probably mean that you need a dual diaphragm booster.

80's Monza?

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
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That MC looks like a Centric 130.62028:

[www.amazon.com]

Has anyone on this forum mounted (or tried to mount) a booster in the stock MC location on an FC?

Anyone got an FC they could measure? I'm wondering if a small 7" dual would fit.

I'm stuck out in New York for the time being, with no FC, and I would sure appreciate it. Thank you.

Chuck
Seattle

Here is one posted by some one a couple weeks ago. Booster

While its possible to run vaccum lines from the engine to the firewall, the compressibility of air might make it inefficient. Another option might be a hydraulic master cylinder designed for use with a slave cylinder. That's basically what hydraulic brakes are. I have been told that getting the right size MC will yield the best results for the least modifications.

66RTVair
Oregon
1965 Corsa 140 stock
1966 Monza DP Racecar
1968 Monza Parts for now

**Everything below subject to checking**

I don't know if I can get enough vacuum at the end of a Greenbrier-long pipe to pull a booster, (most boosters require at least 21 inches of vacuum to operate properly), but my first question was whether I could even fit a dual 7-inch booster at the Greenbrier's stock master cylinder location under the driver's floor.

If a booster fits, chances are good it'd work, though. Volkswagen ran a 12mm ID metal tube from the intake manifold of the Type II (Bus, Transporter, Kombi, etc) up to a booster under the driver's floor. This was back before they started making test results up.

If a booster can't be made to fit, I might mow a few extra lawns for one of those MPB remote boosters, mount it close to the engine and not worry about the vacuum inches. Or put the same money toward one of those Street Rod / Universal Hydraulic Brake Assist Units (thanks Bob).

If it can, but the suck isn't sufficient, a little 12V pneumatic pump like the lumpy-cam racers use should do the trick. One advantage of those is, if your engine dies, your brake pedal doesn't go with it.

Chuck
Seattle

Seems like I remember some XKE Jags as well as some Volvos from the 60s had remote power brake boosters.

>>>Seems like I remember some XKE Jags as well as some Volvos from the
>>>60s had remote power brake boosters.

If a complete system from one of those could be found and modified to fit the Corvair, it might be a good solution.

Getting crazy . . . I don't see any reason a vacuum booster and MC could not be placed in the engine compartment. That gives direct access to vacuum. The MC doesn't care where it is. You then have to make a master cylinder that actuates a slave cylinder to push the MC attached to the booster in back. Like a clutch MC/Slave. Theoretically possible but I am not sure it's cheaper, let alone better, than buying an electric actuated booster. The plumbing might be a tangle and space in the engine compartment is already at a premium.

66RTVair
Oregon
1965 Corsa 140 stock
1966 Monza DP Racecar
1968 Monza Parts for now

If you need vacuum, My 84 Chevy Celebrity had a vacuum motor mounted under the left side headlight. The last of the HO V6 Carb models had a problem getting enough vacuum to operate the disc/drum brakes. It would run on ignition on, then shut-off as the vacuum reached a certain level, letting the engine supply it. There are power brake units operated by power steering pumps. Now there is a Corvair nightmare.

A friend measured the master cylinder space and sent some pictures. It's tight in there. And backed up against the frame rail by moving steering parts. I don't think even the tiny 6" single-diaphragm '70s Toyota Corolla booster would fit. Looks like this van is going to get either a remote booster, the hydraulic assist or no booster.

Question about using a combination valve on a Corvair: the proportioning valve part is preset at the factory, correct? But what if the front-to-rear weight bias is different than what it's set for, such as in a rear-engined car? Does it automatically self-adjust somehow?

Thanks for all your help.

Chuck
Seattle

Mr. Bernoulli says vacuum at the front of a Corvair is the same as in the engine compartment. There is no flow in loved!

Frank DuVal

Fredericksburg, VA

>>> Mr. Bernoulli says vacuum at the front of a Corvair is the same as in the
>>> engine compartment. There is no flow in loved!

Isn't that in a perfectly sealed system? I know the front engine cars hoses leak like a sieve. One would have to make a very tight setup, like metal tube and fittings, to maintain vacuum from the engine to the MC. I suppose a really good rubber hose might do the trick if used with a steel line in the tunnel. It's those connections that will be difficult. Then again, if the Corsa vacuum gauge is accurate, maybe a larger plastic line as used on the gauge might work.

What do you think? I am curious because I am considering trying it.

66RTVair
Oregon
1965 Corsa 140 stock
1966 Monza DP Racecar
1968 Monza Parts for now

Hose shouldn't leak. Unless you are talking ppm in very small numbers. You've got 140, 145, or 164 cubic inches of pumping to keep that line under vacuum.

I would run steel or Cunifer tubing from front to rear. Not because I was afraid of some leak, but because the hard tube installation would be NEAT.

If your hoses leak on your front engine car, replace them, something is wrong. No modern car could operate all the vacuum motors and still pass emissions if leaks are that bad.

Waiting for scientists to respond " but over 1 decade the vacuum will drop by the admittance of 3 cc of air because nature abhors a vacuum!

BTW, the statement I typed on my phone was "There is no flow involved". Of course the iPhone changed it to "in loved"!

Frank DuVal

Fredericksburg, VA