Graco 287877 Piston Valve - Aftermarket Replacement | Bedford 58-3178

This aftermarket piston valve restores check action and pressure stability in popular Graco airless pump lowers. It references OEM 287877 and Bedford 58-3178 for dependable fit within specified pump families.

Aftermarket Precision-Machined Industrial Duty

Why Choose This Piston Valve

  • Restores prime, output consistency, and smooth pressure ramp in compatible pump lowers.
  • Precision seat and ball interface supports repeatable sealing after rebuilds.
  • Aftermarket value from Bedford without changing OEM service procedures.

Color cue: body hardware typically presents a natural steel/silver finish; seals/retainers follow OEM color identifiers where applicable.

Typical Compatibility

  • Ultra Max II 695 and 795 pump lowers (contractor/standard variants).
  • LineLazer IV 3900 pump lower assemblies used for striping duty.

Confirm your sprayer model and parts list before ordering to ensure the correct valve and seating style.

What This Product Fits

  • Graco Ultra Max II 695 (select models/series that specify 287877 in the pump lower BOM).
  • Graco Ultra Max II 795 (select models/series that specify 287877).
  • Graco LineLazer IV 3900 pump lowers that list 287877 in the parts list.

Cross-references shown are guidance; always match by your sprayer’s exact catalog number and bill of materials.

Technical Specifications

Aftermarket Bedford 58-3178
OEM 287877
FitsUltra Max II 695/795; LineLazer IV 3900 pump lowers (model-dependent)
TypePiston valve (check assembly for pump lower)
MaterialHardened seat/ball components with OEM-style interfaces
FunctionControls one-way flow and maintains prime/pressure in the lower
PressureUse within the sprayer’s published working pressure rating
BrandBedford Precision Parts (Aftermarket)

Refer to your sprayer service manual for torque values, lubricant type, and check ball orientation.

Installation Notes

  1. Relieve pressure and flush material; disconnect power source.
  2. Remove the pump lower; disassemble per the model-specific manual.
  3. Clean bores/seats; inspect for scratches or pitting before reassembly.
  4. Install the piston valve with the correct seat/ball orientation; apply the specified lubricant.
  5. Reassemble and test at low pressure, then verify prime and pressure stability.

Tech tip: Replace mating seats and balls together to maximize service life after a rebuild.

When to Rebuild / Replace

  • Loss of prime or slow to build pressure under normal duty.
  • Fluttering pressure or surging during spray.
  • Back-leakage at the check leading to inconsistent output.
  • Visible wear, pitting, or seat damage during inspection.

Bedford vs OEM Comparison

FeatureBedford Aftermarket (58-3178)OEM (Graco)
Fit & InterfaceMatches OEM geometry for listed pump lowersFactory pattern
MaterialsHardened seat/ball componentsOEM-specified set
AvailabilityIf in stock, ships from Bedford Precision Parts in Bedford Hill, New York.Ships via Graco distribution
ValueCost-effective service optionOEM brand program

FAQs

Yes. Bedford 58-3178 is referenced against OEM 287877 for the listed Ultra Max II and LineLazer pump lowers. Confirm against your parts list before purchase.
Ultra Max II 695/795 and LineLazer IV 3900 families that include 287877 in the pump lower bill of materials.
Standard hand tools are typically sufficient. Follow torque values, lubrication, and assembly order in your Graco service manual.
Persistent loss of prime, surging, or visible seat/ball wear during inspection are common indicators to service the piston valve.
If in stock, orders ship from Bedford Precision Parts, Bedford Hill, NY through your chosen carrier/service.