Recently a DOT inspector asked for documentation describing the location of the air supply double check. Has any one had any experience in this area? We have no service information or parts location for this item. The system uses a single compartmented air tank. Thanks all.
bfaulkner-Sorry for late reply-no he did not describe much detail-only that it could not be found. The system is a standard air brake unit-single axle/spring brake system. It has EC-60 Bendix ABS also. I believe the function is to isolate the primary/secondary/wet supply systems from each other in case of air leaks.
Not enough information on the bus, but these are your choices. The early Bendix 121 systems used a separate double check valve, usually somewhere next to, or plumbed with the SR-1 valve.
Bendix changed all there valves to a new style. The double check valve is now built into the PP-1 valve. This now makes it a PP-DC valve.
That firewall valve only applies to buses with a park brake interlock. On that note, if anyone has that feature and you start to experience an air leak inside the bus with the key on, which moves to under the hood with the key off, and you get random aggressive braking...that check valve has failed.
IH CES Air supply double check valve
Posted - 06/14/2018 : 02:00:58 AM
