Description
This backup washer, piston valve is a direct-fit replacement for H.E.R.O part 02-40-2010, used in HERO 400, HERO 401, HERO 500 (HERO). It installs in the original position with no modification.
Common reasons this backup washer, piston valve is replaced:
- Leaking at the seal, gland, or mating face
- Pressure loss during operation
- Hardening, cracking, or flattening with age
- Routine replacement during a pump or gun rebuild
Manufactured to OEM-equivalent dimensions for proper fit and performance. Compatible equipment models are listed in the Compatible Equipment section below, where available.









