power brakes for 40 ford

[Thomas Sargent]

I have installed a dual cylinder master cylinder 1" bore on my 1940 ford. (from early Mustang I am told) I have also installed Bendix style brakes on all four corners. 2" wide shoes. I would like to know if anyone has done similar and also installed a power booster. I have 18" vac at idle. engine is flathead, any input would be appreciated.

 

[Thomas Sargent]

Here is a pix of my master cyl

 

[petehoovie]

Here is a pix of my master cyl

 

[john in illinois]

I have the same brake parts on my model A Tudor with 16" wheels. I have driven it many miles including through the rocky mtn. passes and never felt the need for a booster.

I also have Boling Brothers Bendix brakes and Mustang master cylinder. on my AV8 roadster.

John

 

[rich b]

If you are capable, you could fabricate a bracket and mount a small dual diaphragm booster and master cylinder farther to the rear where the area between the frame rail and X rail is wider; then operate it with a longer push rod (for strength, I usually use DOM tube for long pushrods).

Another way (like back to the '70s) is a single master along with a hydrovac booster.

 

[glennpm]

Another way (like back to the '70s) is a single master along with a hydrovac booster.

I have had a Midland Hy-Power Booster aka Hydrovac on my '40 for years with a single chamber master cylinder. It is excellent with disk brakes in front. Note that these boosters make pedal effort easier. If you have a low pedal arm ratio, you can benefit by using a larger diameter master cylinder bore such as used on disk brake applications. This will give you more volume per stroke inch and also give less pedal effort with a booster.

I went through two originals and now have a rebuilt one done by Ed Strain whom I recommend, https://brakeboosterrebuild.com/rebuilds/

This is my post on the Midland unit. https://www.fordbarn.com/forum/showpost.php?p=1614768&postcount=10 Read the whole thread.

There are also dual remotes for dual pot master cylinders. Note that 70% of braking is from the front only. For my '32 but what I have now with a stepped bore master cylinder works very well, but hey, another unnecessary Winter project for me Here is a link to previous discussion, https://www.fordbarn.com/forum/showthread.php?t=315565&highlight=stepped&showall=1 If I do boost my '32 braking, I would just use it for the front drums.


Here is a pricey dual remote, https://mpbrakes.com/product/bs1011k-dual-diaphragm-remote-brake-booster/

A couple of threads from the HAMB

https://www.jalopyjournal.com/forum/threads/remote-brake-boosters.1216131/

https://www.jalopyjournal.com/forum/threads/remote-mounted-hydro-vac-units.1002886/

 

[V8 Bob]

I have installed a dual cylinder master cylinder 1" bore on my 1940 ford. (from early Mustang I am told) I have also installed Bendix style brakes on all four corners. 2" wide shoes. I would like to know if anyone has done similar and also installed a power booster. I have 18" vac at idle. engine is flathead, any input would be appreciated.

Why do you think you need a booster?


I would caution the use of power assist with 4 wheel Bendix style servo drum brakes on low to mid-weight vehicles, like your '40, because touchy heavy braking and/or erratic handling can result, especially if the stock non-power pedal ratio has not been reduced for power assist, imo.


Keep in mind many vehicles in this weight class came from the factory with manual drum/drum and some disc/drum brakes until the mid-late '70s when power disc/drum became the norm.


JFYI, I run manual 1' dual masters on my disc/drum '32,'40, and drum/drum '51 with no issues.