Plunger 18mm L-112,1mm

The 18 mm AM piston (plunger) is a working component of a high-pressure pump used in Quadro and Therm pump systems. It is responsible for generating pressure in the pump section, so its condition directly affects performance, operating stability, and the service life of sealing elements.

MPN / reference: 40.455

APPLICATION

The plunger is used in service work on industrial pressure washer pumps, including:

• replacement of the piston/plunger in AM pumps used in Quadro/Therm,
• regeneration of the pump working section after long-term operation,
• repairs after pressure performance deterioration,
• pump overhauls with simultaneous inspection of seals and guiding elements.

SYMPTOMS - WHEN IT IS WORTH REPLACING

Typical symptoms of plunger wear or damage:

• drop in working pressure and reduced performance,
• jet pulsation and unstable pump operation (after excluding nozzle/valves),
• leaks in the pump section related to accelerated seal wear,
• unusual noise/friction in the pump area,
• scratches, pitting, or other damage to the working surface after disassembly.

HOW TO CHOOSE THE RIGHT ELEMENT

Piston/plunger selection should be carried out precisely:

• by MPN / manufacturer reference: 40.455,
• by type designation: 18 mm, AM variant,
• by comparison with the disassembled part: verify diameter, length, and geometry.

Precise matching is crucial for pump section tightness and seal durability - an incorrect element can cause rapid wear and loss of performance.

COMPATIBILITY

The element is described as intended for use in pumps for Quadro and Therm series.
For safe selection, compatibility should be confirmed by MPN 40.455 and the pump documentation/parts list. Selection based only on the “18 mm” description or series name without reference verification is not recommended.

[faq]

Does the 18 mm AM plunger fit every Quadro/Therm pump?|No. There are different pump variants within these series. The safest method is to confirm by MPN 40.455 and compare with the disassembled part.

When replacing the plunger, is it worth replacing seals as well?|In service practice, often yes, because worn seals can shorten the life of a new plunger and worsen system tightness.

Can I use a replacement piston/plunger?|A replacement can be considered only with full compatibility of dimensions, geometry, and working-surface quality. In pump working elements, tolerances are critical, so MPN and technical documentation should be the reference point.

[/faq]