This is American Pneumatic Tool part number 1280583535, which replaced the older number 00356 exhaust valve, stocked at Crowder Supply as APT356. It directs the flow that reverses the piston in the rock drill. Valve wear changes port timing, and the machine loses blow rate before it loses the ability to run.
The published breakdown lists it on the 138 Rock Drill and 155 Rock Drill. Compare it to the reference callout on the diagram to be sure it is the position you need.
If you need the parts around it, the full diagram library has the full breakdown library, and the APT lineup covers the machines themselves. Denver stock, with same-day shipment on in-stock orders in by 4 PM ET.
- Part number: 1280583535
- Previous part number: 00356
- Manufacturer: American Pneumatic Tool
- Crowder SKU: APT356
- Listed on breakdowns for: 138 Rock Drill, 155 Rock Drill
