RELAY VALVE MAINTENANCE (MODEL WPES-1).
This task consists of:
General Mechanics Tool Kit (Appendix B, Section III, Item 4)
Airbrake hoses disconnected from towing vehicle (TM 104610-240-10).
All four air chamber compression springs caged (TM 10-4610-240-10).
General Safety Instructions
Compressed air in airbrake system can be dangerous. Wear proper eye protection.
Compressed air can blow dust into eyes. Wear eye protection and open drain cock slowly to avoid a
sudden rush of air when releasing reservoir pressure.
a. Open drain cock (1) slowly to release air pressure from reservoir (2).
Ensure that airflow from reservoir has stopped before closing drain cock.
b. Tag and disconnect four hoses (7, 8, 9 and 10) from relay valve (17).
c. Tag and disconnect three tubes (3, 6, and 12).
d. Remove three locknuts (13), and lower relay valve (17) from frame (14).
e. Remove adapter (15) from relay valve (17).
f. Remove tube elbows (4, 5, and 11) from relay valve (17).