Valve Chest is the Tamco/Toku service part carried under part number 430126F90. 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.
Crowder’s breakdowns list this part on the TJ 20 Rock Drill (RD 40). It comes off the Tamco/Toku TJ-20 Rock Drill.
The rest of the assembly is on the same breakdown, and every diagram we publish is indexed on the parts diagram hub. Ships from our Denver warehouse; in-stock parts ordered by 4 PM ET go out the same day.
- Part number: 430126F90
- Manufacturer: Tamco/Toku
- Crowder SKU: TK-430126F90
- Listed on breakdowns for: TJ 20 Rock Drill (RD 40)

