hydra boost working too well

[Scout-It-Out]

I put hydra boost on my Scout a while ago and it works great... On the road. On the trail it is so sensitive that it's very hard to control with my left foot. The master cyl. Has a bore id of 1.25" I was thinking of getting a different master with a smaller bore. Maybe less fluid moving would make the brake peddle require more effort? Any thoughts? Ideas?? Thanks!

1979 Scout II 304 v8 all stock motor
all stock brakes; disc front, drum rear and prop valve.
Astro van master cyl and hydra booster.
I did add a separate return in the ps pump for the hyraboost.

 

[Scout-It-Out]

I did some testing, albeit not very scientific I tried a panic stop on dirt at about 2 mph. All four tires slid about a foot. I then did the same test on pavement, only the rears locked up. I ordered a new prop valve. We'll see what that does. I also ordered an adjustable prop valve that I May install in the rear if the new stock one doesn't fix it.

 

[ihpartsjeff]

If either doesn't fix the problem I suggest swapping out the master cylinder next. Sounds like you're on the right track though.

 

[Scout-It-Out]

Thanks for the reply Jeff!

I installed the new prop valve and an adjustable prop valve in the rear. Nothing helped! I got to thinking, it almost acts like oil on the brake shoes. Well, brake shoes are cheap so I got some this morning. When I was putting them on, I noticed the one side of one of the wheel cylinders didn't move. I could move the other end freely! Turns out the rear wheel cylinders were rusted inside and not working properly. I replaced them and the problem is solved!!! I can now make the front tires lock up by adjusting the prop valve!