D4OPTRS 40 2019
PROBLEM
Low pressure
Pump runs extremely
rough, pressure low
Water leakage from under
the inlet manifold
Oil leaking between
crankcase and pumping
section
Oil leaking in the area of
crankshaft
Excessive play in the end of
the crankshaft pulley
Water in crankcase
CAUSE
Worn nozzles
Belt slippage
Air leak in inlet plumbing
High pressure relief valve
stuck open or improperly
adjusted
Inlet suction strainer clogged
Fouled or dirty inlet or
discharge valves
Worn inlet or discharge
valves
Leaky discharge hose
Inlet restrictions and/or air
leaks. Damaged cup or stuck
inlet or discharge valve
Worn inlet manifold seals
Leaking sleeve o’rings
Worn crankcase piston rod
seals
Worn crankshaft seal or
improperly installed oil seal
retainer o’ring
Bad bearing
Worn main bearing from
excessive tension on drive
belt
May be caused by humid air
condensing into water inside
the crankcase
SOLUTION
Replace with nozzles of
proper size.
Tighten or replace, use
correct belt.
Disassemble, reseal and
reassemble.
Clean and adjust relief
valve, check for worn and
dirty valve seats.
Clean, check more
frequently.
Clean inlet and discharge
valve assemblies.
Replace worn valves, valve
seats.
Repair or replace.
Clean out foreign material,
replace worn or damaged
cups or valves.
Install new seals.
Replace o’rings.
Replace crankcase piston
rod seals.
Remove oil seal retainer
and replace damaged o’ring
and/or seals.
Replace bearing.
Replace bearing, properly
tension belt.
Change out in 3 months
or 500 hour intervals using
30 weight non-detergent
premium hydraulic oil with
anti-wear and rust inhibitor
additives.
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