R-8 RELAY VALVE. FOR USE WITH THE REAR BRAKES ON M939 SERIES TRUCKS THAT DO NOT HAVE ABS BRAKES. 

PORT SIZES: 

SUPPLY - 3/4"NPT

DELIVERY - 1/2"NPT

1/4"NPT PLUG FROM THE EXISTING VALVE WILL NEED TO BE RE USED IN THE THIRD PORT. 

2 RELAY VALVES USED PER TRUCK,ONE ON EACH REAR AXLE. 

PART #11669105 / 288781  NSN 4820-01-107-9695, 4820011079695