When the pump on a homeowner pressure washer fails, the usual assumption is that the machine is finished. Often it is not: the engine is fine, and the pump is a bolt-on part.

The RXV series exists for that swap. A 3/4 in hollow shaft, a common bolt pattern, and a brass head in place of the aluminium one most consumer machines ship with.

The three RXV Series pumps

All three share: 3,400 RPM, 8.8 lbs, 3.35 oz oil capacity, 3/4 in GHA inlet and 22 mm x 1.4 mm M discharge.

Pick by what your engine can drive

The temptation is to buy the 3.5 GPM model because more is better. It is not, unless the engine can turn it.

EBHP is GPM times PSI divided by 1,460, so the three models need 5.1, 6.2 and 7.2 HP at the shaft. A 160cc engine rated around 5 HP will not drive the 3.5 GPM pump to its rating. Match the pump to the engine you have, not to the number you want.

Check the shaft too: 3/4 in hollow. Most 140 to 200cc residential engines use it, but measure rather than assume.

What “EZ” means

The EZ start valve relieves pressure in the head at startup. On a pull-start engine that is the difference between a machine that starts on the second pull and one that fights back, because a triplex pump under pressure is genuinely hard to turn over by hand.

It is a small feature and it is the one people notice first.

Why the brass head matters

Consumer machines usually ship with an aluminium-head pump, which is cheap and light and corrodes. Brass lasts considerably longer under the same conditions, and unlike the original it can be rebuilt: valve, piston, water seal, oil seal and O-ring kits are all available.

That is the actual case for the upgrade. You are not just replacing a pump, you are replacing it with one that can be serviced instead of discarded.

Where RXV pumps fit

• Driveways, sidewalks and patios
• Decks in wood, composite or stone
• Siding, fencing and outdoor furniture
• Cars, ATVs, mowers and trailers
• General seasonal property maintenance

At 3,000 PSI be deliberate around painted wood and older mortar. This is enough pressure to do damage on softer surfaces.

These are cold-water pumps. A maximum inlet temperature is not published for them, so if you are feeding warm water from anywhere, ask us to confirm before you do.

Making an RXV pump last

• Check the oil often. The crankcase holds 3.35 oz, so a small loss is a large percentage. Use AR64545, the 4.5 oz small-frame pump oil.
• Match the nozzle to your flow. A #2.5 tip on a 3.5 GPM pump overpressures it; a #3.5 tip on a 2.5 GPM pump never builds pressure.
• Flush after soap so residue does not sit in the seals.
• Do not leave it in bypass. At 3,400 RPM with a small crankcase, bypass water heats quickly.
• Winterise. Drain or run pump saver before any storage below freezing. A cracked head is how most of these end.

Replacing a failed pump? Send your engine size and shaft diameter and you will get the model that matches what you already have.