Guide · Couplers, adapters and swivels
A leaking fitting: wrong bore, worn O-ring or a hose to replace
Stop and depressurize first. Then check the pairing (an M22 that threads on can still leak if the bores differ) and the O-ring. Never sealant; replace a damaged hose.
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Short answer
Stop the machine and relieve pressure first. Then check two things: the pairing and the seal. An M22 fitting that threads on can still leak if its bore differs from the other side, and a leaking connection gets a new O-ring of the right size, never sealant. If the hose itself is damaged, replace the hose.
1. Depressurize
Champion's 100384 manual gives the order: engage the trigger lock, turn the unit off, shut off the water, then release the latch and squeeze the trigger. It says never to disconnect the high-pressure hose while the system is pressurized.[2] Do this before you loosen anything, even a quick-connect. More in injection injuries and depressurizing first.
2. Check the pairing: M22 14 mm vs 15 mm
M22 x 14 mm and M22 x 15 mm fittings share the same outside thread and differ only in the inner stem diameter, so they can screw together and still not seal.[3] AR Blue Clean says a 14 mm stem in a 15 mm bore will leak, and a 15 mm stem will not fit into a 14 mm bore.[3]
If a new hose or gun leaks at an M22 joint from the first use, a bore mismatch is the first suspect. Do not force or modify the fitting; AR warns against forcing mismatched connections. Find each side's bore from its maker, then use matching parts or a rated adapter. The M22 14 mm and M22 15 mm pages, and M22 14 mm vs 15 mm, show how to tell them apart.
3. Check the O-ring
Champion's manuals say never to repair leaking connections with sealant but to replace damaged O-rings.[1][2] The O-ring is part-specific, so get the size from the part's maker:
| Maker and part | O-ring as listed |
|---|---|
| Champion 100384, hose and wand connections | 14 x 9 x 2.5 mm[2] |
| ProPulse consumer UberFlex hose | 14 mm OD x 10 mm ID x 2 mm[4] |
ProPulse also says it does not sell replacement O-rings.[4] The two sizes above differ, which is the point: an O-ring that looks right may not be.
4. Tape and sealant
Swagelok says tapered pipe threads seal on the threads and always need a sealant, while straight threads seal with a gasket, O-ring or metal contact, so sealant is not required or recommended on them.[5] The hose and wand connections in Champion's parts list carry an O-ring, as the table above shows. Tape on a straight thread does not fix a worn or missing O-ring.
One maker-specific exception: Westinghouse's PWEXT manual tells users to put thread seal tape on that kit's inlet fitting threads.[6] Follow that instruction for that kit only, not as general advice. See NPT vs BSP vs M22 threads for which threads are tapered.
5. A damaged hose: replace it
Champion's 100386 manual says to stop using the high-pressure hose and replace it immediately if its outer covering is damaged, because a kinked or damaged hose can leak and cause injection injury.[1] It also says never to repair a high-pressure hose, but to replace it.[1] How to choose a replacement hose covers ends and ratings.
6. Leaks inside the machine
A leak from the pump or the machine body is not a fitting problem. For its residential machines, Kärcher refers leaking seals to a service partner.[7] Stop there and contact your maker's service center. We do not cover pump repair.
Parts for the two common fixes
Picks that fit2 products
Sun Joe SPX-M22M2F: the M22 14 mm male to M22 15 mm female adapter, only where you have confirmed one side is 15 mm male and the other 14 mm female.
More on choosing
Flexzilla HFZPW3425M: the 1/4 in x 25 ft hose with M22 fittings on a 14 mm stem, as a replacement for a damaged hose on a 14 mm system; keep its working pressure above your machine's maximum. On Amazon, check that Ships from / Sold by is Amazon.com or the brand.
Sun Joe's own M22 adapter for its SPX series
Sun Joe SPX‑M22M2F 14 mm M22 male to 15 mm M22 female high-pressure hose adapter, brass
M22 hose with a stated 14 mm stem
Flexzilla HFZPW3425M pressure washer hose, 1/4 in x 25 ft, M22 (14 mm stem)
Next
Questions
Why is my pressure washer hose connection leaking?
Usually the pairing or the seal. AR Blue Clean says M22 14 mm and 15 mm fittings share the same outside thread, so they can screw together and still not seal; a 14 mm stem in a 15 mm bore will leak. Otherwise, check for a damaged O-ring.[3]
Can I use Teflon tape on a pressure washer fitting?
Not to fix a leaking O-ring connection. Champion's manuals say never to repair leaking connections with sealant but to replace damaged O-rings, and Swagelok says straight threads seal with a gasket or O-ring, so sealant is not required or recommended on them.[2][5]
What size O-ring is in a pressure washer hose?
It varies by maker. Champion's 100384 parts list shows a 14 x 9 x 2.5 mm O-ring at the hose and wand connections, while ProPulse lists its consumer UberFlex O-rings as 14 mm OD x 10 mm ID x 2 mm. Get the size from your part's maker.[2][4]
Can I hold a leaking fitting to stop the spray?
No. Champion warns that leaking hoses and fittings can cause injection injury and that hoses and fittings should not be held. Shut down and relieve pressure first.[1]