VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 Vacuum assist on my 1934 Master Chevy

I just came across a NOS, never used.. Complete Kit... with mounting brackets and nuts & bolts and hoses for a 1934 Chevy DA.... (1934 Chevrolet Model DA NOS Vacuum Brake System Chevy Bragg Kliesrath BK Power) $130
My Question... Is this vacuum assist actually helpful ...?? I have new linings on my shoes... and the drums are smooth (not scored) and I am wondering if this Vacuum assist just makes the pushing of the peddle easier... or does it actually put more pressure on the cables.. and lock up the brakes easier...?? anybody here have experience using this vacuum system....
maybe Chevy Nut knows about these.....????

My question is, is it still good after almost 90 years + I never heard of such a thing. If your "34 brakes are working righr you should not need a power brake add on.

Here is the eBay link ... https://www.ebay.com/itm/155753019959?hash=item24439a7a37 It looks like New and all the rubber is still pliable..... I know my new linings on my Brakes... have not yet formed themselves to the drums shape.... they are still wearing in after driving it only about150 miles (4 town trips)..... I am still adjusting them tighter as they wear... but I can not lock all four wheels, on the pavement... so what I hear you saying Gene... is that this vacuum assist unit will not improve my braking...??? is that right ???

A friend who had a 1930 large 8 cylinder full classic Willies would find and pick up manuals and sales ads for older obscure automotive mechanical components. One of the ones he found was similar to what you are talking about. The ad showed a nicely dressed woman driving a large sedan, and that was the market it was designed for. A very large car with mechanical brakes. While it may be interesting and cool, personally it may be hard to fit it to your car and probably more trouble than it was worth to get it adjusted properly. Yes, the brakes in those days were kind of an afterthought and rather anemic. But they were adequate for the size and weight of the car.

OK... the message I am getting thus far... is they my stock brakes... adjusted correctly and all in good condition... will work just fine..... without this vacuum devise..... if you look at the listing... they have detailed directions for mounting and adjusting them on a 1934 Chevrolet Master..... DA model only..... made for my particular DA model....

If you need more brakeing in an emergency pull up the hand brake. It works on all 4 weels and can assist the pedal pressure (for 1934 and 1935 Master models)

FYI - the 1934 has thin stamped steel brake drums and they overheat fast.

I worked at a place where we rebuilt these type units. Had a customer with a 1934 Cadillac gives me a very similar unit to do. BK is an early name for Bendix brake. (The Cad brakes were very similar to the Chevy style, just larger.( ie S-cam, Huck style). This unit only uses vacuum to "assist" you with brake pedal pressure. Also similar to the vacuum assist for shifting that came out in '39. I was very interested in my customers reaction to the "assist" he got after the unit was put back into operating condition. He said, "I can feel it working now, but really doesn't do a whole lot." Of course, this unit is a precursor to the Bendix Hydrovac which used vacuum and hydraulics to make braking easier in cars and trucks.
It might be interesting to install one in your car and see what it does to "assist". Don't think it could hurt anything.
Of course, high quality wireback or HD open woven lining develop the most friction, with the least pedal effort ,and will give you the overall best braking results, with or without an assisting unit.

I know the drums are stamped steel... and heat up much faster and warp & fade, as well... but unlike the model A ford parts... there are No Cast Iron drums that inter change with these steel drums.... Going down this long mountain road that drops 2,000 ft in 2 miles... I just put it in first gear and use the engine compression all the way down the long steep hill....using brakes only rarely... when the compression is not enough to keep the engine from revving too high... so I have adjusted my driving habits in many ways to accommodate the cars limitations..... i drive like they did in 1934..... Slow and easy... never in a hurry... out for the ride... not the destination....
I bought the softer woven lining material... that has soft brass fibers woven into it.... They are still seating to the drum....I am sure they will improve with more use..... I love driving this car... it takes me back to a time where mankind was functioning at a much slower pace... Less stress in peoples lives.... No Hurry... No Worries.....
I am NOT buying the vacuum devise...I will be putting the money to better use elsewhere.... like for more gas.. to drive it more often...