The hydro boost unit in my M37 started leaking fluid and due to the age of the unit I replaced it. That happened 6 months ago, but now the front brakes are building up pressure without applying the brake pedal. I also just replaced the master cylinder. It takes about three miles or so before the brakes start to lock up. Not sure if anyone has any advise about trouble shooting the unit.

 

M37 Links
try this link, seemed to have everything powerwagon when I was looking for stuff for a
'53 that I almost got. GOOD LUCK!
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Also, I was reading the Sticky for this...think you posted in the wrong forum. Possibly not many readers may find this.