BD brake questions

[ANCIENT WOOD]

I just bought a new BD brake for my dads pickup (birthday-fathers day gift). I installed it saturday and set the backpressure at 13# (stock 12 valve). I took it for a test drive and when I engaged it at 1700 rpm the backpressure hit 42#. I readjusted the idle backpressure to 7# and the driving results were the same. I then swapped the brake and spool valve from my truck to his and tried the same tests with the same results. Is this typical with the BD on a 12 valve? If I need to change the valve springs how much of a job is it? Is there a mechanic in the mid columbia gorge or Portland area that is recommendable for this job? How much would it cost? It seems to be a lot of backpressure for the stock springs. I appreciate any help offered.

Dan Beck

 

[ramman]

Thats about the same pressures that I read,I think there is an internal spring in the brake for max pressure. The valve springs are not to bad,a very good spring compressor required to install the 60# springs as the spring has to be completely compressed to allow the keepers to be installed. Raising the idle pressure didn't change the max on mine at 2800 rpm I will see 47# or so most of the time in normal use it's 40-42#.

 

[Bob Wagner]

If I were you

I would give Piers a call 604-853-9396