Maintenance Technique — Underground
MTU80001
HD Pressure Pump — MT3222 3314 6664
Digital Work Instruction

Water Piston Cup Seal & Check Valve Replacement

HD pressure pump assembly MT3222 3314 6664 — animated, timed procedure for use on site via QR code or the MT Underground portal.

Document No.
MTU80001
Machine / Group
HD Pressure Pump
Document Author
Luke Rogers
Date
27 Aug 2026
Site procedures take priority Follow all site-specific safety procedures and permits at all times — this instruction does not replace your site SWMS, JSA or isolation permit.

Background

This instruction addresses a water piston cup seal bypass fault on the HD pressure pump, identified by fluid discharge at the pump's water-out "tell-tale" port. Actioning the reseal as soon as the tell-tale symptom appears avoids oil and water cross-contamination inside the pump assembly.

Procedure

7 steps · 0:00–0:35
MP4 not yet embedded
⏳ Video pending — source AVI supplied, MP4 embed to follow
0:000:35

    Reference

    Tools & parts

    As called out in the procedure steps
    • MT3222 3314 668 — HD Pump Seal Kit (cup seals & check valve O-rings)
    • Seal pick or approved seal-removal tooling
    • 6 mm inhex socket — SHCS end-cap fasteners
    • Torque wrench — SHCS to 81 Nm (lubricated)
    • Isolation equipment per site permit

    Site PPE & isolation

    As per site specific requirements

    Follow the PPE, isolation and permit requirements of the site this work is performed on.