Top 20 Dewalt DPD3100 Gas Pressure Washer Questions & Answers

Question edited for clarity, full 'make model (what it is)'. Question moved to a better category. This says you don't need it. You just need a 3/8 plug.145'F is the temperature it opens. https://mastertoolrepair.com/portable-gas-pressure-washer-parts-type1-dp3750-p-1687081.html There is one here, aftermarket type I guess https://cvindustrialhardware.com/shop/dewalt/valve-thermal-relief/ More here https://www.google.com/search?q=dp3750+thermal+relief+valve ..

These are the two simplest causes: crankcase overfill situation . . check oil level and adjust as needed. air filter blockage causing the engine vacuum to draw from the crankcase breather and the engine oil with it.

Common problem across brands. When you spray water the drop in pressure triggers the motor to take the hose pressure ~ 30 psi and boost it to ~ 3000 psi. Water coats these parts with calcium (hard water) or other junk and water contains bacteria which causes slime and scale. Once that pressure switch / valve is sufficiently clogged it doesn't move smoothly so it can fluctuate between sending a yes / no signal about whether you are squeezing the trigger or not. This causes the pulsing. EZ test: take the the tip off the wand, start the unit, squeeze trigger - should run continously with no problem. If it does for sure you need to watch a video on dissembling and cleaning the valve body. It is not hard but you must work carefully to avoid losing parts especially springs and take digital pictures to record the order for reassembly.

Quite often it means that your water supply is too small... not enough gallons / minute.

regular unleaded hop that helped you

see if it has a low oil shut off and the oil is just at the level

See this diagram:
http://www.mastertoolrepair.com/images/DPD3100_pump.jpg?osCsid=1f3m03ijp5lcht6569kran6rk2

Remove Items 122 (Un;loader) and 138 (Thermail relief). Clean them up as best you can with a nylon brush under some slow running water. Dis-assemble the unloader valve completly to clean (both ends). Then lubrcate them with White Grease and reinstall both parts AFTER placing White grease in the cavity the valves mount into. Very briefly... Test water flow with the engine not running Then start the unit with water off and let run 30 seconds. Turn off engine. Turn ON water supply and test water flow engine OFF. Note you will get a certain amount of white grease initially that passes through the unit. Start unit and rapidly actuate the trigger 1/2 second on 1/2 second off multiple times to force the unloader valve to cycle.

You can get parts here if either of the valves have completly failed:
http://www.mastertoolrepair.com/dewalt-dpd3100-n001194-pump-p-59405.html

The above steps should get your presure washer working properly again.
Thanks for choosing FixYa,
Kelly

In the Pump Dewalt recommends
DeWalt DP70 Pressure Washer Pump OilIn the engine Dewalt Recommends
SAE 10W-30 is recommended for general use

first things first, before replacing I would wrap this valve with teflon tape and then retighten and see if the leak stops, I checked the entire schematic and found no listing for a spring so this is part of a valve assembly of some type. It might be the unloader or the thermal valve so if there is any doubt about getting the right pressure on the cap I would replace the valve to ensure safety. the valves I saw are less than 25.00 so for the price I personally would replace. check the surrounding area for cracks also. Now as where to buy parts, you can go to Dewaltservicenet.com and download a parts breakdown of the pump assembly and also other areas for this washer. You can also buy the parts online from them. Let me know if you need more assistance

The pressure unloader us usually the first part/s that fail. An unloader can fail resulting in no or very low pressure or good pressure, however will not unload when trigger is released and stall the motor. Look at breakdown for your pump and determine if unloader parts are available and reasonable. If too costly to replace these parts then install an ez start valve to help start engine and tie back wand handle to deal with unloader problem (workaround). Ez start valve can be seen here:
http://www.cmcpwe.com/accessorystartvalve.html

When not in use, store washer with oil in pump to displace the water. The oil will help lube internal parts and possibly cause the unloader to begin working (if stuck due to debris/rust). You can find a gizmo to help you feed oil into pump on ebay /other web locations. Good luck with your repair.

hi there perrinex22x

here is web site for parts

http://www.ereplacementparts.com/dewalt-dpd3100-pressure-washer-parts-c-1009_7440_7445.html

from diagram looks like not listed as seperate part

may need to remove them and see if your local bearing/ belt store distributor in your area may be able to source them

from list pt number N001194 pump assy is 505 $


sorry

here is another web site that may help for needle roller brgs - give a try

http://www.locateballbearings.com/roller-bearing-suppliers.html


cheers hope it helps pauly46

There is a low oil level sensor on the opposite side of the engine as the oil fill / dipstick. The next time that your presure washer acts up disconnect ONE wire to the oil level sensor. On pressure washers mose engines have the oil level sensor removed for just this reason. You tip the engine to move the power washer and you can not start it or.. if you move it with the unit running the oil level sensor kills the ignition. Just make sure that anytime you are going to use it that you ensure the oil level is properly serviced. (Each use)

There is yet another possibility. Debris in the bottom of the fuel bowl will draft directly into the lower fuel jet (Located inthe bowl nut area) with a tip of the unit and clog the fuel nozzle. You can prove you have a fuel problem simply by adding gas to the carb throat with the air filter removed. If you get a brief start... you have a fuel not a spark problem. Turn off the fuel selector... remove the fuel float bowl nut and drop the float bowl. Use carb cleaner in the threaded area to clean out the orifice in the body of the carb and then remove the debris from the float bowl. CLEAN the bowl nut also.

Use a spray can lid for the next step under the float bowl area.
BRIEFLY
Open the fuel selector and gently lift the float to level. Fuel must shut off when near level and re-start fuel flow as you lower the float. The spray paint can lid should fill up in 8 seconds or less. If you have poor fuel flow start looking at the bottom of the gas tank or an inline fuel filter as the problem. Some fuel selectors have tiny bowls under the fuel selector lever. Make sure to clean this out also if you have one.

Turn off the fuel selector. Reinstall the float bowl making sure the rubber bowl gasket is fitted properly. Fuel selector ON... leak test. Then test start the unit and see if your symptom is gone.

Thanks for choosing FixYa,
Kelly

Take the hose off the gun and see if water comes out. If so the gun has to be taken apart and cleaned. Also where the water hose goes in to the machine there is a screen filter which you might have to clean if water is not comming out on the gun side. Use a screwdriver and pry it out carefully around the edges Clean the screen with a wire brush and put it back in and try it.

Go to http://servicenet.dewalt.com/Products/Detail/DP3100#. On the right side there's a Downloads section, pull the scroll button all the way down, the last download listed is your manual. You can either download a PDF or have it emailed to you.

The coupler that the nozzle goes into uses a 1/4" EPDM o-ring. This o-ring needs to be replaced. You can find them at most major hardware stores or purchase them by contact us at 800.247.8103 or visiting www.landanw.com.

Sincerely,
Aron Kerr
Landa Northwest
www.landanw.com

Hi and welcome to FixYa, I am Kelly

From reading everything I can find, i.e User's manual & parts manual the only thing you add oil too is the engine. The pressure pump does not have a liquid sump.

You can look at parts here detail D:
http://www.ereplacementparts.com/dewalt-dpd3100-pressure-washer-parts-c-1009_7440_7445.html

So too add oil to the engine you would remove the dip stick from the crank case located on the opposite of the side of the engine as the oil sensor.

I recommend you use 30 WT SAE oil for 3 oil changes then on the 4th oil change use an HD 30 WT oil. The oil drain plug is located in the center of the side of the engine crank case base. On the 5th Oil change switch back to SAE 30 WT oil. Oil brands are not really important. They all have to meet SAE the same standards to carry the label of SAE. (Yes you can use a generic 30 WT SAE oil )
Thanks for choosing FixYa,
Kelly

Hi and welcome to FixYa, I am Kelly.

I note that your question was 3 months ago. I answered a current post today that had your exact same symptoms. Your post was revealed after I answered the current post. Had I seen your post 90 days ago I would have responded with the same answer as follows:

There is a low oil level sensor on the opposite side of the engine as the oil fill / dipstick. The next time that your presure washer acts up disconnect ONE wire to the oil level sensor. On pressure washers mose engines have the oil level sensor removed for just this reason. You tip the engine to move the power washer and you can not start it or.. if you move it with the unit running the oil level sensor kills the ignition. Just make sure that anytime you are going to use it that you ensure the oil level is properly serviced. (Each use)

There is yet another possibility. Debris in the bottom of the fuel bowl will draft directly into the lower fuel jet (Located inthe bowl nut area) with a tip of the unit and clog the fuel nozzle. You can prove you have a fuel problem simply by adding gas to the carb throat with the air filter removed. If you get a brief start... you have a fuel not a spark problem. Turn off the fuel selector... remove the fuel float bowl nut and drop the float bowl. Use carb cleaner in the threaded area to clean out the orifice in the body of the carb and then remove the debris from the float bowl. CLEAN the bowl nut also.

Use a spray can lid for the next step under the float bowl area.
BRIEFLY
Open the fuel selector and gently lift the float to level. Fuel must shut off when near level and re-start fuel flow as you lower the float. The spray paint can lid should fill up in 8 seconds or less. If you have poor fuel flow start looking at the bottom of the gas tank or an inline fuel filter as the problem. Some fuel selectors have tiny bowls under the fuel selector lever. Make sure to clean this out also if you have one.

Turn off the fuel selector. Reinstall the float bowl making sure the rubber bowl gasket is fitted properly. Fuel selector ON... leak test. Then test start the unit and see if your symptom is gone.
One more possibility. Your engine has and E-Z start valve that is supposed to be a compression relief. If this is sitcking / partially open ect.. it can make it hard to start your engine.

I really think you have a low oil level sensor issue that is grounding out the spark because it cycles to ground when you move the unit and is not... sensing the oil level properly after you move the unit. I clean oil level sensors with carb cleaner. You can wake up about 75% of them just by cleaning them off internally through the 2 side holes cleaning up to the contact area on the top of the sensor.
Thanks for choosing FixYa,
Kelly

There is a little window on the side of the pump to see the oil level but thats normaly the problem None of these companys make there owen pumps or engines i owen serveral power washers if you can tell me more about the problem Iwill likely know how to fix it see who made the pump and the engine and let me know pier_j

It looks as if moisture/water has contaminated the oil. Check the level of oil from the glass window. It must be high. Drain out the oil & check if water is present, if so then replace the entire oil.

First: check and change the spark plug and do a oil change (OIL IS NOT THE PROBLEM BUT IS GOOD TO DO IT) then do a test with fresh gasoline. Second:check all fuel components (LINES,CARB,ETC...) Third:if any of this fix the problem your machine need service.