Gas Pressure Washer: Pressure washer won't mix detergent with spray

Using the wrong spray tip to apply detergent can prevent the detergent from mixing properly with the spray. Use the low-pressure spray tip (usually the black tip) when applying detergent. A clog in the detergent siphon tube can also inhibit proper detergent mixing. Check the siphon tube for a clog and clean the tube if necessary. If the siphon tube is clear, then you'll likely need to replace the chemical injection kit on your pressure washer.

gas pressure washer

These repairs may help solve your gas pressure washer problem

Repair the pressure washer chemical injection system

Repair the pressure washer chemical injection system

The chemical injection system siphons detergent from the soap container and mixes the detergent with the spray. If the detergent doesn't flow through the system, check the chemical injection components for clogs or defective parts. Replace any defective chemical injection components.

How to install a pressure washer chemical injection kit

If your pressuring washer isn't spraying soap, the chemical injection valve might be the problem. This repair guide shows how to replace it with a pressure washer chemical injection kit, in 5 easy steps.

Repair difficulty
Time required
 15 minutes or less
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Symptoms for gas pressure washers

Choose a symptom to see related pressure washer repairs.

Things to do: tune up the engine, inject pump saver into the water pump when storing the pressure washer for the winter
Main causes: broken recoil spring, damaged recoil starter
Main causes: overfilling engine with oil, improper fuel/air mixture, choke system problems, dirty carburetor, engine needs tune up
Main causes: dirty air filter, stale fuel, clogged or dirty carburetor, bad unloader valve
Main causes: pump running for more than 5 minutes when the spray wand isn't being used, faulty pressure relief valve, bad unloader valve
Main causes: damaged recoil starter, oil inside cylinder, locked up engine piston
Main causes: using a high-pressure spray tip when applying detergent, clogged siphon tube, chemical injection system failure
Main causes: stale fuel, gummed up carburetor, engine needs tune up, throttle and choke controls need adjustment, bad recoil starter
Main causes: insufficient water supply, clogged water inlet screen, clogged pressure hose, faulty pump check valves, stuck unloader valve

Repair guides for gas pressure washers

These step-by-step repair guides will help you safely fix what’s broken on your pressure washer.

April 1, 2013
By Lyle Weischwill
How to replace a pressure washer pump

The pump can be damaged by air in the inlet water supply or by chemicals that remain in the pump body after using the chemical injection system. Follow these steps to replace a damaged pump.

Repair difficulty
Time required
 30 minutes or less
April 1, 2013
By Lyle Weischwill
How to install a pressure washer O-ring kit

O-rings seal fittings on the pressure washer pump. Damaged seals allow water to leak from the pump. Follow these steps to replace the O-rings in a leaking pressure washer pump.

Repair difficulty
Time required
 45 minutes or less
How to install a pressure washer chemical injection kit

The chemical injection valve draws detergent into the pump. If it’s not drawing detergent, use a repair kit to replace the chemical injection valve.

Repair difficulty
Time required
 15 minutes or less

Articles and videos for gas pressure washers

Use the advice and tips in these articles and videos to get the most out of your pressure washer.

January 1, 2016

Choosing the correct spray tip for a pressure washer

By Sears PartsDirect staff

Spray tips vary in pressure and angle of spray. This guide matches the spray tip to the cleaning job.

November 1, 2015

7 steps for winterizing and storing a pressure washer

By Sears PartsDirect staff

Follow this advice to winterize your pressure washer.

April 1, 2015

Pressure washer common questions

By Sears PartsDirect staff

See what you can learn from the questions that people most often ask our experts about their pressure washers.