A. Water Supply (Cold Water Only)
1. Check faucet. 4.0 gpm is required.
2. Outside diameter of hose should be 3/4”.
3. Maximum length of hose should be 50’.
4. The inlet water pressure should not exceed 90 psi.
5. Hose should not be kinked or damaged.
B. Nozzle
1. Check function and setting of original spray wand nozzle (not pic-
tured) by using an in-house nozzle. If pump functions properly
with in-house nozzle but malfunctions with original nozzle, replace
nozzle.
C. Water Inlet Filter
1. Remove filter with pair of valve pliers. (figure 1)
2. Clean filter.
3. Replace filter if it is torn, bent or missing.
4. Reinstall filter.
Note: If water inlet filter is missing or damaged,
further damage may have occurred inside the pump.
D. Bypass Valve
1. Remove fastening cap and deflector cap. (figure 2)
2. Remove thermal relief valve housing. (figure 3)
3. Pull out bypass valve. (figure 4)
4. Inspect bypass valve for damage and lubrication.
Inadequate lubrication will cause valve to stick.
5. Inspect O-rings for nicks or cuts. Replace if necessary.
6. Grease only large O-rings with lithium grease. (figure 4 inset)
7. Replace bypass valve.
E. High-Pressure Check Valve
1. Remove valve plate by tapping plate with screwdriver
and hammer. (figure 5)
2. Remove 3 plastic valve caps. (figure 5 inset)
8
SECTION 1 / LOW WATER PRESSURE SOLUTIONS
A. Water Supply
B. Nozzle
C. Water Inlet Filter
D. Bypass Valve
E. High Pressure Check Valve
figure 1
figure 2
figure 3
figure 5
figure 4
plastic
valve caps
Pump 777 9/28/01 3:56 PM Page 8
www.mymowerparts.com
For Karcher Pressure Washer Parts Call 606-678-9623 or 606-561-4983
