4-42. RATIO RELAY VALVE MAINTENANCE (Con't).
b. LEAKAGE TEST
Wear safety goggles and face shield when performing leakage tests on ratio
relay valve (3). Failure to follow this warning may result in serious eye injury
due to high pressure air.
if leaks are found which cannot be corrected after performing leakage test,
remove ratio relay valve (3) and replace damaged components.
With air system fully pressurized, apply a soap solution to ratio relay valve (3) and check for leaks.
No leakage is allowed. if leaks are found, tighten fittings.
Tag air lines, fittings, and valve ports as they are removed to ensure
if disconnecting air lines to remove air reservoir (10 or 12), perform
steps 1 through 4.
(1) Disconnect tractor EMERGENCY and SERVICE air couplings from semitrailer (see para-
graph 2-14). Pull
on draincock cable (9) and release all air from front and rear air reservoirs
(10 and 12).