Swirl & Shine

How to Maintain a Pressure Washer

Almost every dead electric washer died of the same two things: something in the inlet screen, or water left in the pump. Both take under a minute to prevent.

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Electric pressure washers have a reputation for being disposable, and it is only half deserved. They do fail early — but the two failures that account for most of it are both preventable, and both preventions take under a minute.

Manufacturer guidance is remarkably consistent on this. Briggs & Stratton recommend checking the inlet screen, the high-pressure connections and O-rings, and the nozzle orifices prior to each use, and relieving line pressure after each use. That is the whole routine, and almost nobody does it.

The inlet screen — the part nobody checks

Where the garden hose connects to the machine there is a small mesh filter. Its job is to stop grit, rust and hose debris reaching the pump.

When it clogs, water flow to the pump is restricted, and a starved pump cavitates— vapor bubbles form and collapse violently against the internals. That is what pulsing and surging feel like, and it is genuinely destructive over time.

The check:unscrew the inlet fitting, pull the screen out with pliers or a small hook, and rinse it under a faucet. Briggs & Stratton’s instruction is to flush it with clear water if dirty or clogged, and to replace it along with its rubber washer if damaged. Thirty seconds, before each use, and it prevents the most common cause of premature pump failure.

A related habit worth adopting: run the hose for a few seconds before connecting it to flush out whatever has settled in it.

Relieve the pressure after every use

When you switch the motor off, the hose and gun are still holding several hundred PSI. Leaving them like that puts a static load on the seals, hose and trigger assembly for however long the machine sits.

The routine:switch the motor off first, then turn the water off, then squeeze the trigger until all the water in the line is expelled and the flow stops. Briggs & Stratton list holding the trigger to expel remaining water as an after-each-use step for exactly this reason.

Do this before disconnecting anything. It also means the hose is not spraying at you when you undo the fitting.

O-rings and connections

Every threaded and quick-connect joint on the machine seals on a small rubber O-ring, and those are consumables. They flatten, harden and crack, and the symptom is a joint that weeps under pressure.

The check:before each use, look at the connections for leaks or damage. Briggs & Stratton’s guidance is simply to replace O-rings if connectors leak — they cost almost nothing and an assortment pack lives in a drawer for years.

This is also where the M22 14 mm versus 15 mm question matters: a joint that leaks despite a new O-ring may not be a worn seal at all, but a mismatched inner stem. The threads engage; the seal never had a chance.

Nozzles and orifices

A pressure washer tip is a precision orifice, and a partial blockage changes both the spray pattern and the pressure reaching the paint — which matters when you are working inside a safe pressure window.

The check: inspect the tips for a distorted or split spray pattern. Clear a blocked orifice with the wire tool supplied with the machine, pushed through from the outlet side, then back-flush with water. Mineral deposits that resist usually release after a soak in dilute vinegar. Replace tips that are damaged rather than persevering.

The same applies to a foam cannon: its brass orifice and mesh screen scale up in hard water, and a cannon that has gradually got worse at foaming is very often just blocked.

Never run it dry

The pump is lubricated and cooled by the water moving through it. Run it dry, even briefly, and the seals take heat they were never meant to see.

The order that prevents it:

  1. Connect the hose and turn the water on.
  2. Squeeze the trigger until water flows steadily, purging air from the line.
  3. Only then switch the motor on.
  4. When finished, switch the motor off before turning the water off.
  5. Squeeze the trigger to relieve the remaining pressure.

Related: do not leave the machine running with the trigger closed for long periods. Most units go into bypass, where water circulates internally and heats up, and several minutes of that is hard on the pump. If you are stopping to work a panel, switch it off.

Descaling in hard water

If you live somewhere hard-water, scale accumulates in the pump and gradually narrows the internal passages. The symptom is falling pressure over a season or two that nothing else accounts for — screen clean, nozzle clear, hose fine, and it still is not what it was.

A descaling solution poured into the pump through the inlet, left for the interval the maker specifies, then flushed through with clean water for several minutes, will typically restore it. Do it once a season in a hard-water area; in a soft-water area you may never need to.

Storage, which is where machines actually die

More electric washers are killed by storage than by use, and the mechanism is simple: water left in the pump over winter freezes, expands, and cracks the housing. That is a terminal failure on a consumer machine.

Greenworks’ own winterizing procedure is the template — drain the hoses and gun, flush the pump, add pump saver or RV antifreeze, and store off cold concrete when it will be sitting more than thirty days. The full walk-through is in storing a pressure washer for winter, and it is twenty minutes in autumn against the price of a new machine.

Off-season storage rules apply the rest of the year too: coil the hose without kinks rather than folding it, keep the gun and tips somewhere they will not be stepped on, and store the unit indoors if you can.

The whole routine, honestly

Stated as a habit rather than a schedule:

  • Before each use: glance at the inlet screen, the connections and the tip. Flush the hose. Purge air before switching on.
  • After each use: motor off, water off, trigger squeezed to relieve pressure. Coil the hose properly.
  • Each season: descale if your water is hard, and replace any O-ring that has weeped.
  • Before winter: drain, flush and add pump saver.

That is genuinely all of it, and it is the difference between a machine that lasts two seasons and one that is still washing the car in ten years.

Frequently asked questions

What maintenance does an electric pressure washer need?

Very little, and most of it is before and after each use rather than scheduled. Briggs & Stratton's own guidance is to check the inlet screen, the high-pressure connections and O-rings, and the nozzle orifices prior to every use, and to relieve the pressure in the line after every use. Beyond that, descaling in hard-water areas and proper winter storage cover almost everything.

Why is my pressure washer pulsing or surging?

Most commonly it is starved of water, and the first thing to check is the inlet screen. A clogged screen restricts flow to the pump and causes cavitation, which is exactly what pulsing feels like. Other causes are a partially closed faucet, a kinked hose, a clogged nozzle orifice, or air trapped in the line that has not been purged.

How do I clean a pressure washer nozzle?

Use the wire tool supplied with the machine, or a fine needle, pushed through the orifice from the outlet side, then back-flush by running water through the tip in reverse. Mineral deposits that resist that will usually release after a soak in a dilute vinegar solution. A partially blocked tip shows up as a distorted spray pattern or an unexpected pressure change.

Should I run my pressure washer dry?

Never, even briefly. The pump relies on the water passing through it for lubrication and cooling, and running it dry for even a short period can damage seals. Always turn the water on and squeeze the trigger to purge air before switching the motor on, and switch the motor off before turning the water off.

Do I need to descale a pressure washer?

In a hard-water area, periodically — yes. Mineral scale builds up in the pump and narrows the passages over time, which shows as gradually falling pressure that nothing else explains. A descaling solution run through the inlet and left for the interval the maker specifies, then flushed with clean water, restores it. In a soft-water area you may never need to.

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