Brake Boosters

[29 Chandler]

Were there cars, other tham Chandler, that could come equipped with the Westinghouse Vaccum booster? What other systems were out there (1920's-1930's)? I've heard that RR also had a vaccum system, but if you had a vaccum leak you would also lose your brakes.

There must be others out there.

[Guest carlnut50]

I have an old friend who says he had a 1935 ford with an aftermarket vac brake booster.He says it worked very well.I have no idea what brand it was.

[Guest]

Interesting... my 1916 American Lafrance came with the remnants of a vacumn booster setup (vacumn tap on the intake manifold, valve on the foot brake rod, and some obviously-added-later levers near the backing plates). I had no idea they were used this early on.

I would like to know more about early vacumn boosters, in the hopes of recreating the one on my ALF. It could sure use the help! In fairness though, these units were not always poor stoppers ? we have a '13 ALF at our local historic park and it has remarkably good brakes, both hand and foot.

[29 Chandler]

Wanted to share with the DF this E-mail I recived in response to my query on Brake Boosters.

I tried twice to answer your query on the forum but I might not follow the

correct procedure as I was not able to get my message through....

French Voisins had a vacuum brakes system in the twenties and early

thirties, under the name of " servo frein Dewandre " which was actually a

Westinghouse licensee. It worked beautifully after some practice to get used

to the soft and precise feeling of the pedal on which there was no stepping

as with the current systems of the time ; there was no risk of losing the

brakes in case of vacuum leak, as the system was used to assist the

operation of the normal mechanical brakes ; in case of interruption of the

vacuum, such as coasting with the engine stopped, the mechanical system

still worked normally ( and in this case you had to step hard ! ) I have a

booklet on servo frein Dewandre somewhere in my papers but I am afraid it is

in French.

There was a special care to be observed as for lubrication of the system,

which was never to use mineral oil ; as the main seal was leather one should

use only " huile de pied de boeuf " my poor English does not allow me for a

precise translation but it was an animal

oil obtained by boiling beefs' feet ; it was mainly used by watchmakers for

what I think you call grand-father's clocks.

People who developed at the time mechanical assistance to braking, such as

Renault and Hispano-Suiza, criticized the vacuum system by saying that

braking would change the fuel mixture from rich to lean, which would cause

burning of the exhaust valves ; of course this could not happen with the

Voisin engine, which was sleeve-valve. My personal experience is that the

vacuum system was much more efficient and nicer to use that the mechanical

one working by a kind of friction clutch on the gearbox ; with this last

system, the faster you went the stronger the assistance ; when you were

about to stop there was no assistance left and then you better had to use

the hand brake ; nothing of that precise and positive feeling of the vacuum

brake.

In the late seventies I was just about to buy a huge Chandler torpedo, I

think eight in line, which was still in daily use . But that was in

Mandalay, Burma, and there was no way of taking the car out of the

country.....

Best regards Henri Frémon

GAR 1928

Thanks Henri !!!

[oldcar]

By the mid to late 1920s Renault had their own mechanical brake "servo' driven off the rear of the gearbox.

oldcar.

[Rusty_OToole]

Westinghouse air brakes date back to 1869, but according to one reference the first car with vacuum power brakes was 1928 Pierce Arrow.

The gearbox driven servo clutch booster predates this I think.

" huile de pied de boeuf " is probably what we call in English, Neat's Foot Oil. This is a popular treatment for softening and preserving leather and keeping it flexible.

[JACK M]

I had a Bentley with servo brakes, worked well unless you were already stopped. Like if you parked on a hill, release the parking brake and the car would roll a couple of feet no matter how hard you held the brake pedal.

[bhambulldog]

I had a Bentley with servo brakes, worked well unless you were already stopped. Like if you parked on a hill, release the parking brake and the car would roll a couple of feet no matter how hard you held the brake pedal.

I have occasion to drive a '52 Bentley and a '39 Rolls Royce.

What you speak of, is a maddening feature...

[JACK M]

I have occasion to drive a '52 Bentley and a '39 Rolls Royce.

What you speak of, is a maddening feature...

True dat !!!!