Model A Hydraulic Brake Conversion

Once your brakes lock up there is nothing more to do.

Rebuild your mechanical brakes properly, you’ll be well served.
 
The one thing I love about our cars is I don't have to worry about leaky brakes.
Mechanicals are always there, without any hassles.
 
Hello, my car has the Boling Brake conversion when I bought it, I would prefer a restored mechanical brake system given a choice, do have a Model a chassis that could be used for parts , had hydraulic brakes lock up on long storage, mechanical brakes serve well if set up correctly.
 
Mechanical brakes are great for Model A's if in good shape and correctly adjusted. I cannot see modern cars using mechanical brakes. Why?

The brake fluid used in juice brakes makes all the difference. Silicon based fluid is non-hygroscopic, meaning it does not absorb any water. Often used in classic and vintage cars and military type vehicles because silicone based brake fluid will not corrode internal brake parts nor will it damage paint work. Do not mix different brake fluids. Completely clean out the brake system before changing fluids.
 
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Bob C said:
I'm still trying to figure out what "rear spring purch mount cutout dust covers" are.
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Some hydraulic conversions involve cutting out a rectangular "window" into the rear backing plate in order to allow clearance for the shock arm ball mount. This leaves an opening for which a dust cover can be made or, before they closed shop, was available from Cling's Aftermarket Parts. Don't know if anybody else makes them.
 
I don’t understand why people think that locking up the brakes on a car is proof the brakes are good. Locking up the brakes is bad. Once the car is in a skid you have lost control of braking. Not good if it is mechanical or hydraulic brakes. You stop faster and more safely if you can pump the brakes and avoid a lockup. I’m almost 60 year since graduating from engineering school, but I recall learning this as a freshman or sophomore.
 
Russ, You are absolutely right. The static friction is greater than the sliding friction. But being able to lock up all 4 is an indication that the brakes are good, even if you never should do that.

My dad's 1937 Rolls Royce had mechanical brakes but it had a servo clutch on the transmission that the brakes would activate. The servo would apply the force to the brake cables. If the car started to skid the servo would slow down or stop and the brake force would decrease thus stopping any skidding. It was mechanical equivalent to modern power ABS brakes. It really worked and kept my dad from running into a school bus that had pulled out in front of him.
 
I think the “mechanical brakes can lock the wheels, so it’s sufficient - you won’t stop faster with hydraulic brakes” makes more sense when viewed in the context of tire contact patch. I wonder how the mechanical system can perform with 16” V8 wheels, and how it feels to drive.
Has this been done enough to build a consensus? The only 16” wheel car I know personally has hydraulic brakes.
 
David in San Antonio said:
I think the “mechanical brakes can lock the wheels, so it’s sufficient - you won’t stop faster with hydraulic brakes” makes more sense when viewed in the context of tire contact patch. I wonder how the mechanical system can perform with 16” V8 wheels, and how it feels to drive.
Has this been done enough to build a consensus? The only 16” wheel car I know personally has hydraulic brakes.
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Mechanical brakes, cast iron drums here.

My 1930 A came to me with 16” 215/70 R16 radials. I later installed original size 19” wheels with American Classic Radials. The ACR tires were 1.75” larger diameter than the 16” tires.

My experience is the 16” tires due to their smaller diameter required less pedal force to stop than the 19” ACR tires which requires more pedal force to perform the same stop. Never performed any actual stopping distance test between the two. It only stands to reason that the 16” tires would stop quicker in a panic stop due to increased contact patch area.

I had to learn to be slightly more aggressive with pedal force application with the 19” tires.
 
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