DeWalt DP3900 - Manual (Page 14)

14
English
Engine
Consult the engine instruction manual for the man u fac tur er's recom-
mendations for any and all maintenance.
NOTE: The pressure washer frame is equipped with an oil drain
hole to help make changing the engine oil easier.
Pump
NOTE: The pump was filled with oil at the factory.
1. Change pump oil after the first 10 hours of operation and every
250 hours thereafter.
TO CHECK OIL
1. The oil level should come to the dot in the middle of the sight
glass (Z).
HOW TO CHANGE H
Z
AA
PUMP OIL
1. Loosen pump dipstick/oil
plug (H).
2. Place a container under
the oil drain plug (AA).
3. Remove pump oil drain
plug.
4. After oil is drained, replace
oil drain plug. Tighten securely.
5. Remove pump dipstick/oil plug and fill with 14 oz. (414 ml) of
DP70 pump oil. If DP70 is not available use 30W non-detergent
oil.
6. Replace pump dipstick/oil plug and tighten securely.
Nozzle Cleaning
If the nozzle becomes clogged with foreign materials, such as dirt,
excessive pressure may develop. If the nozzle becomes partially
clogged or restricted, the pump pressure will pulsate. Clean the
nozzle immediately using the nozzle kit supplied and the following
instructions:
1. Shut off the pressure washer and turn off the water supply.
2. Pull trigger on gun handle to relieve any water pressure.
3. Disconnect the spray wand from the gun.
BB
4. Remove the high-pressure nozzle from
the spray wand. Remove any obstructions
with the nozzle cleaning tool (BB) provid-
ed and back flush with clean water.
5. Direct water supply into spray wand to
back flush loosened particles for 30
seconds.
6. Reassemble the nozzle to the wand.
7. Reconnect spray wand to gun then turn on water supply.
8. Start pressure washer and place spray wand into high pressure
setting to test.
To Clean the Water Inlet Filter
This filter screen (V) should
V
V
be checked periodically and
cleaned if necessary.
1. Remove the filter screen
(V) by grasping the end
and removing it from
water inlet of pump.
2. Clean filter by flushing it
with water on both sides.