Brass leak-off ring 18mm AP

The 18 mm brass (leakage) ring for the AP pump is a service component operating in the pump’s sealing area, associated with controlling seal working conditions and drainage in the “leakage” zone. In workshop practice, this type of ring is replaced during an AP pump overhaul when wear on the mating surfaces affects the stability of the sealing assembly.

MPN / reference: 41066
Reference dimension: Ø 18 mm

APPLICATION

The ring is used in typical pump service work:

• refurbishment of the sealing assembly in the AP pump,
• replacement of an intermediate component in the “leakage” zone during pump overhaul,
• restoring correct seating and cooperation of the seals,
• servicing heavily used pumps where brass components in the sealing zone wear over time.

SYMPTOMS - WHEN IT’S WORTH REPLACING

Consider replacing the ring when you notice:

• recurring sealing issues in the sealing zone,
• wear marks, scratches, or pitting on mating surfaces,
• deformation or mechanical damage after disassembly,
• unstable operation of the sealing assembly after reassembly,
• issues returning despite replacing the seals themselves (after other causes have been ruled out).

HOW TO CHOOSE THE RIGHT PART

Selection should be unambiguous:

• confirm it is intended for the AP pump and is the “leakage” ring type,
• verify the manufacturer number: MPN 41066,
• check the reference dimension Ø 18 mm and compare geometry with the removed part,
• base selection on the AP pump service documentation.

In the sealing zone, profile and fit matter - parts with similar diameters can differ in details and may not be interchangeable.

COMPATIBILITY

Select the ring based on MPN 41066 and compatibility with the AP pump. The Ø 18 mm parameter is a dimensional hint, but the key identifiers are the manufacturer number and comparison with the removed component.

[faq]

Is the “leakage” ring a sealing element like a lip seal or O-ring?|Not directly. It’s a component that works within the sealing zone; its geometry and surface condition influence how the seals operate. That’s why its wear can produce symptoms similar to worn seals.

What is most commonly seen on a worn brass ring after removal?|Most often scratches, worn contact surfaces, or localized pitting. Such marks can worsen interaction with the seals and cause recurring issues after reassembly.

During an AP pump overhaul, is it better to replace only the ring or the entire sealing set?|It depends on the condition of the other components. In service practice, the whole set is assessed: seals, mating surfaces, and intermediate parts. Replacing only the ring makes sense if the rest is in good condition.

How can I be sure it’s the correct 18 mm ring for an AP pump?|Most reliably by MPN 41066, plus comparing the geometry with the removed part and the AP pump parts list.

What should I check in the pump if the sealing-zone issue persists after replacing the ring?|Check the seats, guides, mating surfaces, and the condition of the remaining seals. Leaks can result from wear of multiple components, not just one ring.

[/faq]