Have a couple air brake questions

[aTX427]

Hey Guys, I have a couple questions related to my air brakes.

First, my system seems to loose air while parked, 20psi per day if the truck is unused - Is that normal?

Secondly, where should I tap into the brake system to add a BrakeSmart trailer brake controller? I was thinking about adding a tee at the guage on the primary system side.

[amunderdog]

Originally Posted by aTX427

Hey Guys, I have a couple questions related to my air brakes.

First, my system seems to loose air while parked, 20psi per day if the truck is unused - Is that normal?
Yes it is normal. Many will lose all air overnight.


Secondly, where should I tap into the brake system to add a BrakeSmart trailer brake controller? I was thinking about adding a tee at the guage on the primary system side.

http://www.brakesmart.biz/docs/peterbilt330.pdf
BrakeSmart - 877-338-7373

[Birken Vogt]

Your best bet is to tee off the stop light switch as the KW diagram shows, if there is only one stop light switch (hopefully). This is because the stop light switch gets its air from both the front and rear air brake signals so if one or the other system is empty due to a failure, the trailer brakes will still come on.

If there are two stop light switches, then you need to use a "double check" valve to the pressure sender. Air brake vendors sell them made for this purpose.

Birken