This is the week before last when I failed to post pictures of the 10 wheel end disassemble assignments.

This week I completed an assignment on control modulating valves. I choose to study the one on the freightliner in our shop. I found the valve, found the part number (550414), found the service information and dissembled it.  

 I had a hard time with one of the screws, I was proud of how mangled it was when i got that sucker out.

a control modulating valve applies the spring brakes gradually, so you can control the spring brakes if the service brakes fail. 

 

This is the break canister I took apart last week, as explained in previous blog.