Hydroboost brake cylinder

[md8810]

Original equipment on a '64 Chev fire truck I had. Neighbor ran it out of gas on a hill lost engine power and brakes. Very common system on many vintage cars and trucks. I had no prior indication that my power brake system was faulty.

[30-9]

Originally Posted by albjerryg

If you have a dual master you will to have 2 of these units, why cannot you just t it of the output and go to both the back and front///Jerry

Good question.

[Talkwrench]

This is my vacuum booster.

[30-9]

With front discs & drum rear do you need two boosters?

[Talkwrench]

Yes or you just boost the front. I did that on my herald.

[adileo]

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Originally Posted by Talkwrench

Yes or you just boost the front. I did that on my herald.

What's that like? Since you have it both ways. What is your assessment?

Thanks Andy

[Kahuna]

If you use only one, on a dual Master cylinder, you defeat the dual purpose Master cylinder advantages, as there is only ONE output from the HydroVAC. Some guys have used one for the front brakes when using Disc brakes up front. Seems to work well that way.
The unit Talkwrench has is like the one I used.
Jim

[Kahuna]

MD8810
If you had a failure due to running out of gas, it wasn't the hydrovac that caused your loss of braking. Something else was amiss.

[Jack E/NJ]

Or you might wanna consider a bendix conversion if you don't like an electric power m/c. http://www.flatheadv8.org/f1brakes1.htm Jack E.NJ

[Talkwrench]

To be honest my assessment on the herald it hasn't helped all that much .. The engineers here made the previous owner put a dual circuit setup on [because it has a 2.5 litre 6 cyl engine] , so he did it by making a ' pedal box' like racing / rally cars, two separate m/c's joint together. However all it did to my mind was double the pressure on the pedal to make it work! It takes a hefty push but it does pull up!

[scooder]

You only need two if the vacuum boosters are remote, and you got dual circuit brakes. like the one pictured above.
If the vacuum booster is between the pedal and the master cylinder you use one. Like the booster under the hood between the master cylinder and firewall on more modern stuff. The commonly available aftermarket dual circuit master cylinders use one booster, with the booster between the master and the pedal.
Martin.