[Mike]

I do not know if the parking brake is disconnected, but the service brake is disconnected when the tag is raised.

[Archived]

When you lift the tag with the TW-1 switch (tag lift) it does 2 things it sends a control signal (air) to the 3 port Norgren that lifts the tag and 2 nd the same signal (air) goes the the diversion valve and it sends air the the tag R-12 valves that are normally open (NO) and it closes them so no parking brake and no service brakes on tag

[DON]

So my purpose of asking this is I have new brake chambers for the tag axle’s that I will be replacing in the next few weekends. I should be able to LIFT the TAG then back up on ramps under the drive wheels, remove the tag wheels and the tag brake chambers without having to screw the bolt in to cage the tag brake chamber because the service and tag parking brake will be disabled because the tag is lifted. Am I on base or off base?

Chuck

[Archived]

The spring will still be in the can, so no, you can not take it off without caging the spring. There is a lot of force behind it and I know of at least 2 drivers who were killed messing with something they did not understand. Shutting off the air does nothing to help with changing the chamber out.

[Corey]

Pay close attention to Mark’s reply.

You cannot replace spring brake chambers without caging the brake. In fact you have to exercise extreme caution when working on brake chambers with spring brakes.

[Archived]

Jon:

Completely understand the power and danger of the caged spring. I do not plan on rebuilding the brake chamber, just doing a direct replacement with the new brake chamber I purchased from Prevost parts.

Chuck