brake upgrade


Gear Grinder
Jan 16, 2011
Willys Model
Willys Year:
I need to upgrade the brakes on my 1951 Willys wagon. It has Scout II axles front and back with front discs, but still the original master cylinder. THe tall tires make is difficult to stop, especially for my wife. I either need to upgrade the brakes or not let her drive it. The second option is not possible since she was very understanding of my need for a new toy.
There is no cheap answer, if you already have front discs make sure they are free moving and apply full braking pressure. You could try a master cylinder with a vacuum booster, several of the forum sponsors sell them. You could also look for a remote mount brake booster like a hydrovac.
First thing I would do is get a dual master cyl. for it. Walks has them, just let him know that you have disc brakes on the front..
The dual master cyl will not only make it safer, there's a good chance that it will help out on your braking too. (disc & drum brakes need different residual pressure, which is (normally) regulated at the master cyl.
Another option would be to go with the GM 3/4ton power assist brakes that were on the diesel;s and some gas powered trucks.
Pavel Has a great website with a wealth of information..
I'm a cheep skate. so I would hit the nearest pick a part and get a dual master cylinder off a truck and buy a rebuild kit for it. But that just me! :twisted:
The location of the master cylinder makes it difficult to upgrade. Yes, you can buy a separate booster/servo and yes there is dual master cylinder for sale made for front dish brakes, like the set provided from Herm the Overdrive Guy.

I have heared about several trying to fit a GM Hydraboost at the original location of the master cylinder, but I guess the steering box will be in the way.

Next option will be to opt for hanging pedals from an early CJ 7, which fits ok. If you take the full pedal and steering column fixture from a van or a larger American car it will probalby fit with some adjustments too. Than you can use the master cylinder and vacuum servo from a CJ 7 or a similar set-up from an other car. Even the Hydraboost will fit. Best is to convert to hanging clutch pedal too, however this requires a different set-up than the original, perhaps a hydraulic system will work better than a cable operated solution, however both are possible.