O-ring 40x3,5mm

The water filter cup is the housing component that contains the filter element and provides a sealed closure of the inlet-water filter assembly on a pressure washer. In service practice, it’s replaced when the cup is cracked, clouded, has damaged threads, or cannot maintain tightness. The set specifies an O-ring 40×3.5 mm, which seals the joint between the cup and the filter body.

MPN / reference: 13302
Intended use: original Kränzle filters
Seal: O-ring 40×3.5 mm

APPLICATION

The filter cup is used in typical inlet-water service work:

• replacing a damaged filter cup in an original Kränzle filter,
• restoring housing tightness after leakage at the joint,
• repairing a filter after thread damage or a cracked cup,
• servicing inlet prefiltration where pump protection from debris is critical.

SYMPTOMS - WHEN IT’S WORTH REPLACING

Consider replacing the cup when you notice:

• water leaking around the filter (at the thread or sealing perimeter),
• cracks, clouding, or deformation of the cup,
• damaged/worn threads that prevent proper tightening,
• inability to maintain tightness even after replacing the O-ring,
• visible impact marks or freeze damage (common if water is left in the filter over winter).

HOW TO CHOOSE THE RIGHT PART

Selection should be unambiguous:

• confirm the filter is an original Kränzle filter,
• verify the manufacturer number: MPN 13302,
• confirm the seal spec: O-ring 40×3.5 mm,
• compare with the removed part: diameter, thread, and seating method.

For filters, even small differences in thread or diameter can prevent proper closure and lead to inlet leaks.

COMPATIBILITY

Select the cup based on MPN 13302 and compatibility with the original Kränzle filter body. Best confirmation is comparison with the removed cup and checking that sealing is done with an O-ring 40×3.5 mm in that filter housing.

[faq]

Does the filter cup really affect pump operation?|Yes. If the cup leaks, the filter can draw in air, destabilizing water supply and worsening pump operating conditions. Leaks can also reduce performance and cause pressure issues.

Why do filters and cups often crack after winter?|Most often because water left in the filter freezes. Ice expands and can split the housing—even if the crack is initially small.

Is replacing only the O-ring enough if the filter is leaking?|Sometimes, yes. But if the cup has micro-cracks, worn threads, or deformation, a new O-ring won’t restore tightness for long. In that case, replacing the cup is the correct fix.

How can I tell the problem is the cup thread and not the seal?|If the cup tightens unevenly, “skips,” won’t start straight, or tightness disappears even with a new O-ring, the thread or the cup itself is a likely culprit.

What should I check after installing a new filter cup?|Leak tightness under inlet pressure, correct O-ring seating in the groove, and clean threads/contact surfaces. Also check the filter element condition so debris doesn’t restrict flow.

[/faq]