User Manual
Plunger Pumps
 Operating Instructions and Parts Manual  RSV Series Pumps
First Choice When Quality Matters
NORTH
AMERICA
Symptom Possible Cause(s) Corrective Action
Low pressure (cont.) 3 Air leak in inlet plumbing 3 Disassemble, reseal and reas-
semble
4 Relief valve stuck, partially 
plugged or improperly 
adjusted valve seat worn
4 Clean and adjust relief valve; 
check for worn or dirty valve 
seats
5 Worn packing. Abrasive 
in pumped in cavitation. 
Inadequate water
5 Install proper filter suction at 
inlet manifold must be limited to 
lifting less than 20 feet of water 
or 8.5 psi vacuum
6 Worn inlet, discharge valve 
blocked or dirty
6 Replace inlet and discharge valve
Pump runs extremely 
rough, pressure very 
low
1 Inlet restrictions and/or air 
leaks.
1 Clean out foreign material
2 Stuck inlet or discharge 
valve
2 Replace worn valves
Water leakage from 
under manifold
Worn packing or cracked 
plunger
Install new packing or plunger
Slight leak, oil leak-
ing in the area of 
crankshaft
1 Worn crankshaft seal or 
improperly installed oil seal 
o-ring
1 Remove oil seal retainer and 
replace damaged 0-ring and/or 
seals
2 Bad bearing 2 Replace bearing
Excessive play in the 
end of the crankshaft 
pulley
Worn main bearing from 
excessive tension on drive 
belt
Replace crankcase bearing and/or 
tension drive belt
Water in crankcase 1 Humid air condensing into 
water inside the crankcase
1 Change oil intervals
2 Worn packing and/or 
cracked plunger
2 Replace packing. Replace 
plunger
Loud knocking noise 
in pump
1 Cavitation or sucking air 1 Check water supply is turned on
2 Pulley loose on crankshaft 2 Check key and tighten set screw
3 Broken or worn bearing 3 Replace bearing
Troubleshooting (cont.)










