Question about Dewalt DPD3100 Gas Pressure Washer

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Dewalt DP3100 Excess pressure stalls engine

When water flow is on and engine running. Pump builds excess pressure that stalls engine & locks up until pressure is released. It blew the valve open.

Posted by Anonymous on


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SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

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Posted on Jan 02, 2017

  • 95 Answers

SOURCE: compressor question

i have that compressor and had that problem. i build professionally so i use it alot. i had it about a year before the regulator quit working which is what yours is doing. i put it back in the box and took it back to lowes

please rate answer

Posted on Mar 21, 2009

  • 1383 Answers

SOURCE: Dewalt 4 gal air compressor will not build pressure in take.

The bleed valve is an unloader of sorts that allows the compressor to start with-out a load. It closes when the pressure in the airline reaches about 20-25lbs with good volume. If air volume is not sufficient, the valve will not close. To solve the problem lets do a few tests. A long cord will reduce power and reduce air volume. Try powering the compressor with-out extension cord. If bleed valve closes when you do not use a cord, the compressor is not getting enough voltage, use shorter cord of the 12 gauge quality and more hose to reach work. If valve still does not close, check for air leaks on all fittings including around pressure switch and drain valve with soapy water. Repair as necessary and retest. If no leaks were found, temporarily plug bleed valve port with screw/bolt and run compressor till set pressure cut-off while counting minuites/seconds. The compressor should fill and shut off within three minutes or so. If it takes an unusually long time to fill, then the reed valves /valve plate is worn and leaking pressure back into cylinger. Leaking valves will usually result in very hot discharge airline/air. Reinstall the bleed valve after test. Parts and partslist are available at . Good luck on the repair and email if you have other questions.

Posted on May 06, 2009

  • 23 Answers

SOURCE: Dewalt compressor will not build up pressure

turn on and tap the top of the pin lightly also with no air in tank pull up and down on pin spray lightly with wd40 never let anyone use this pin valve to release pressure it will ruin the valve if you still have problems you can get a new universal check valve off the shelf at lowes for around $6 make sure you use thread tape when reinstalling

Posted on May 12, 2009

  • 293 Answers

SOURCE: Dewalt d55141 Builds only 45psi

Check the unloading valve. Accumulation of dirt might be preventing the valve to fully close, by-passing a portion of the compressed air.

Posted on Jun 11, 2009

  • 5603 Answers

SOURCE: Relief value releases and will not reset

Likely the check valve is bad or has contamination on the seat. The result is the pressure will bleed back out the compression relief valve which is often as part of the pressure switch.

If the safety valve is the one that is bleeding, then the pressure is set too high at the pressure switch.

Posted on Apr 08, 2010

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By stalling you mean quit or bogs down until you release spray?
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Can't get nozzle to work. not building up enough pressure.

Make sure the injector is turned on. Clean the nozzle or the strainer if either are clogged or blocked. There may also be dried chemicals in the injector; dissolve them by running warm water through the injection tube.
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Sounds like a fuel problem eighter a filter or you have debrie in your fuel tank thats cloging the inlet from the tank to the carburtator . Its that or a problem with the water pump . That could also be clogging and putting exesive back prressure on the engine shaft causeing stalling . What dose your water flow look like do you loose that first before the engine starts to bog down or dose the engine go first and the pressure follow . Also do you winterize the mechine i owen and repair many washers if you need more info you need to give more pier_j

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Got a Dewalt 3800 PSI Pressure Washer with 4.0 GPM with a Honda GX 390 gas engine. Tipped it up to roll it out to my truck and got a big puddle of water with what looked like Pump oil in the puddle. Can...

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sounds like you have either a sticky unloader valve or a blockage causing back pressure to pump causing excess load to engine,a possibility is to check the nozzle at end of wand incase there is a piece of grit there since engine runs okay with no load,another solution is to check venturi that is located beside outlet of pump that you connect hose for wand to for possible wear or blockage,hope this helps

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