Repair Kit - Kränzle Pump Valves

The Kränzle AQ pump valve repair kit is a set of service parts intended for refurbishing the valve section of a high-pressure pump. Replacing valves is a typical repair step when the pump cannot maintain parameters, runs unevenly, or loses performance in the high-pressure system.

MPN / reference: 400621
Weight: 0.079 kg
Dimensions / size (packaging): 10×1×10

APPLICATION

Used for servicing Kränzle AQ pumps, especially for:

• replacing valves in the suction and discharge sections (valve-section refurbishment),
• fixing issues related to pressure loss and unstable operation,
• repairs after operating with contaminated water (deposits affect valve and seat sealing),
• periodic inspections when valve components show wear or leakage.

SYMPTOMS - WHEN IT’S WORTH REPLACING

Typical symptoms of worn pump valves:

• drop in working pressure and reduced output,
• jet pulsation and pressure fluctuations during operation,
• difficulty maintaining stable parameters under load,
• unstable pump behavior after releasing the trigger (pressure rollback/“floating”),
• signs of leakage in the pump after ruling out accessory-side issues (nozzle, gun, filter).

HOW TO CHOOSE THE RIGHT PART

Valve selection should be based on manufacturer data - different pump versions may use different seats and valve types:

• by manufacturer MPN / reference: 400621,
• by pump/series designation: Kränzle AQ pump in Bully/Primus units,
• by comparison with removed parts: verify valve type, dimensions, and seating method.

Accurate fit is critical for valve-section tightness and pressure stability.

COMPATIBILITY

Kit described as intended for the Kränzle AQ pump used in Bully and Primus series units.
For safe selection, confirm compatibility by MPN 400621 and the pump documentation/parts list (table/specification). Selecting only by device name without reference verification is not recommended.

[faq]

Will replacing valves fix pressure drop and pulsation?|Often yes, if valve leakage or wear is the cause. Similar symptoms can also be caused by the nozzle, water filter, air ingress, or an unloader/regulating valve - basic system diagnostics before pump disassembly is recommended.
How do I confirm kit 400621 fits my Bully/Primus unit?|The safest method is verifying MPN 400621 in the parts list for the Kränzle AQ pump. Also compare removed valves with the new ones (type and dimensions).
Can I use aftermarket valve replacements?|Only if type, dimensions, and intended use match exactly. Valve tolerances and sealing on the seats are critical; an incorrect match leads to reduced output and unstable operation. Use the MPN and pump specification as the reference point.

[/faq]