Seal & Repair Kits

Choosing a pressure washer O-ring kit by coupler size and ring dimensions

Start with the leak point. Most O-ring kits target quick connect couplers, trigger gun joints, lance connections and hose ends. The listed ring size matters more than the pack name, so measure or check the old ring against the listing.

The couplers in this range split into two ring sizes. The 1/4 inch and M22 rings share a 9.2mm inner diameter and 14mm outer diameter. The 3/8 inch ring is larger, at 17.1mm outer diameter. A smaller 10 pack ring is also listed at 4.7mm inner and 8.5mm outer diameter, so don't assume it fits a standard coupler.

• 1/4 inch and M22 couplers: 9.2mm ID, 14mm OD
• 3/8 inch couplers: 17.1mm OD
• Mixed kits supply both small and large rings in one pack
• Pack options run from 10 pieces up to 100 pieces

Matching a pump seal kit or repair kit to your machine

A pressure washer pump seal kit is model-specific. The listed pump seal kit supplies 6 seals, 10 O-rings and 3 pilot spacers, and it names the models and series it fits. The listing also tells you to check your pump before ordering, so confirm the pump reference first.

Oil seal and valve kits work differently. The 12mm kit lists TC oil seals in several sizes: 12x20x5x7, 12x20x5.3, 12x20x5.2 and 12x18x5. Valve parts come in D12 diameter with heights H16, H18, H21 and H26.5. Measure the old seal and valve, then pick the exact size.

For Karcher-style K series machines, the O-ring seal kits list K2, K3, K4 and K5, and one coupler kit lists K2 to K7 series. Check the model line on the listing before you buy.

Material choice: NBR, silicone and temperature range

NBR (nitrile) is the main material in these kits. The K2 to K5 set lists it as corrosion resistant and oil resistant, with a working range of -20 to 70 degrees Celsius. That suits typical cold-water cleaners.

Some listings show silicone or a rubber and silicone mix. One set quotes -40°C to 120°C. One kit lists rubber but its image text also mentions silicone, so confirm the material with us if it matters for your duty. Where a listing doesn't state a temperature limit, check before using it with heated water or aggressive chemicals.

The control valve piston is a different part. It's brass and 304 stainless steel, with reference 4.553-268.0, and it adds overpressure protection on the models listed.