Trouble Shooting Pumps
Trouble-Shooting
On-Line Trouble Shooting Guide
Introduction
In nearly all instances, pump failure is the result of improper installation or operation rather than normal wear. One of the most common causes of pump failure is improper or unnecessary service, often as a result of the operator attempting the service.
Each time the pump is serviced, the chance of pump failure as a result of improper service increases. The operator should be left with no reason or desire to open the pump for service.
Usually requests for service are not made until the operation of the equipment has become so bad that it usually does not work.
"The high pressure pump is generally one of the most dependable and best constructed components in a high pressure cleaner. The well-engineered pump may be installed in a not-so-well engineered system. "All pumps have wear parts, which eventually need to be replaced.
"In most cases, the high pressure pump is likely to outlast most other components as long as the pump is installed correctly and the system is operated properly." (This is a quote from "The Universal Guide to High Pressure and Steam Cleaner Repair.")
Pump chattering caused by heavy cavitation can be mistaken for a broken connecting rod. To determine if cavitation is the source of the problem, open the upstream chemical injector completely while operating the system. If the noise leaves it is cavitation. If the system does not have an upstream injector hook up a positive feed system to the pump and operate the system.
Do not assume that the pump is the problem.
Set up a check list.
Excessive noise: Hot water Mounting bolts
_ Cavitation Vibrations in the system
_ Worn valves Worn O-rings
_ Belts Connecting rods
_ Pulleys Plunger rod pins
_ Bearings _
Oil leaks: Bad seals
_ Red shipping cap has no been removed
Loss of pressure: Worn nozzle Packings
_ Bad pressure gauge Valve seat O-rings
_ RPM Inlet pressure or flow
_ Valves _
How to Start
Ask the Right Question At the Right Time
Isolate the Problem
* Set Up a Diagnostic Procedure
* Simple to Hard
* Logical Progression
Use Simple Tools
* Eyes
* Ears
* Nose
* Brain
Start With Observations
* Physical Inspection and Observations
* Carefully Observe the Equipment In Operation
* Trace the Fluid Flow
Disregard False Impressions
Don't Skip Any Steps
* Start At Point "A" and Finish at Point "Z"
* Isolate the Problem
* "Remember, Problems Can Cause Problems"
Pump Failures: There Are Several Reasons for Pump Failure, and Most Are Generally Connected with
* Improper Use
* Insufficient or Dirty Water
* Plugged Filters
* Kinked or Plugged Hoses
* Cavitation
* Lack of Maintenance
Fluid System
NO FLOW:
* No Power to the Pump
* Trigger Gun Not Opening
* No Water Source
* Clogged Spray Nozzle
* Clogged Inlet Filter
* Stuck Float Valve
* Faulty Unloader
* Pinched or Clogged Inlet Hose
* Inlet Valve(s) Not Open
LOW PRESSURE, ADEQUATE FLOW:
* Worn, Incorrect, No Spray Nozzle
* Lance on Low Pressure Setting
* Unloader/Regulator Improperly Adjusted
* Pressure Gauge Inaccurate or Broken
* Worn Pump Packings
LOW PRESSURE, LOW FLOW:
* Volume Improperly Adjusted
* Discharge Leaks
* Chemical Injector Orifice Blocked
* Drive Belts Loose
* Pump or Motor Not Running at Rated Speed
* Stripped Pump Drive Coupling
* Defective Easy Start Valve
* Malfunctioning Motor or Engine
LOW PRESSURE, VERY LOW FLOW:
* Unloader Stuck In Bypass
* Outlet Restriction
* Clogged Nozzle
* Restriction in the High Pressure Hose
* Debris in the System
* Cavitation
* Clogged Inlet Hose or Filter
EXCESSIVE PRESSURE:
* Spray Nozzle Too Small
* Faulty Pressure Gauge
* Unloader/Regulator Improperly Adjusted
* Faulty Unloader/Regulator
PUMP CHATTERS:
* Air in the System
* Chemical Line Not Submerged
* Inlet Line Kinked, Restricted, or Internal Hose Separation
* Inadequate Water Supply
* Float Valve Is Stuck
* Turbulence in the Float/Supply Tank
* Cavitation
* Inlet or Inlet Strainer Clogged
* Water Supply Too Hot
INLET LINE VIBRATION:
* Air in the System
* Debris in the Valves
OUTLET LINE VIBRATES:
* Air in the System
* Debris in the Discharge Valves
* Damaged Pump Packings
INLET & OUTLET LINES VIBRATE:
* Inlet and/or Discharge Valves Fouled
* Other Downstream Restrictions
* Air in the System
UNLOADERSIREGULATORS VERY LOW OR NO FLOW:
* Unloader Stuck In Bypass
UNLOADER CYCLES WITH SYSTEM UNDER PRESSURE (FLOW UNLOADER):
* Improper Flow
* Nozzle Too Small
* Nozzle Clogged
* Improper Unloader Orifice
* Unloader Orifice Clogged
* Injector Orifice Clogged
UNLOADER CYCLES WITH THE SYSTEM IN BYPASS (FLOW UNLOADER):
* No Restriction in the Unloader
* Weep Gun in the System
* Downstream Leakage
* Accumulator Downstream
UNLOADER PRODUCES SMOOTH FLOW & LOW VOLUME (TRAP UNLOADER):
* Unloader Adjusted Too Low
* Spray Nozzle Clogged
* Spray Nozzle Too Small
* Injector Orifice Blocked
UNLOADER PRODUCES SMOOTH FLOW & LOW VOLUME (FLOW UNLOADER):
* Unloader Adjusted Too Low
* Unloader Is Stuck in Bypass
* Restriction in the System
UNLOADER PRODUCES LOW FLOW & NORMAL PRESSURE (TRAP UNLOADER):
* Nozzle Too Small
UNLOADER PRODUCES LOW FLOW & NORMAL PRESSURE (FLOW UNLOADER):
* Nozzle Too Small
UNLOADER PRESSURE INCREASES WHEN THE TRIGGER IS RELEASED (FLOW):
* Unloader Piston is Stuck or Frozen
* Bypass Port Is Clogged or Restricted
* Excessive Tension on the Main Spring
LEAKING:
* Leaking from the Inlet:
* Bad Inlet Hose Seal
* Loose Clamps or Connections
* Leaking from the Float Tank:
* Float Is Full of Water or Stuck
* Leaking from the Pressure Fittings:
* Fittings Not Tightened or Sealed
* Leaking from the Quick Disconnects:
* Bad O-Ring
* Leaking from the Pump:
* Bad Low Pressure Seal(s)
* Cracked Plunger
* Damaged Manifold
* Leaking from the Trigger Gun:
* Bad Piston O-Ring
* Stripped Connection
* Leaking from the Nozzle:
* Weep Gun
* Damaged Gun Valve Ball & Seat
* Leaking from the Pop Off Valve:
* System Over Pressure
* Clogged Nozzle
* Trigger Gun Not Working
* Excessive Pressure Spikes
* Wear on the Ball & Seat
Trigger Gun
NO FLOW FROM THE NOZZLE WHEN THE TRIGGER IS DEPRESSED:
* Broken Rod in the Trigger Gun
* Blockage in the System Past the Trigger Gun
EXCESSIVE PRESSURE WHEN THE TRIGGER GUN IS RELEASED:
* Excessive Pressure Spike
* Malfunctioning Unloader
FLOW DOES NOT STOP WHEN THE TRIGGER IS RELEASED:
* Broken Return Spring
* Debris in the Gun Valve
TRIGGER ACTION STICKS:
* Keeper Is Too Tight
Chemical System
NO CHEMICAL:
* Chemical Valve Is Closed
* Chemical Foot Strainer Is Clogged
* Chemical Line Is Kinked
* No Adjustment for Low Pressure
* Chemical Nozzle Not Sized Properly
* Wrong Size Chemical Orifice
EXCESSIVE CHEMICAL:
* Valve Improperly Adjusted
SPRAY NOZZLE:
* Spray Pattern Irregular.-
* Clogged Nozzle
* Worn Nozzle
* Volume Proper, Pressure Low.-
* Nozzle Is Too Large
* Internal Nozzle Wear
* Pressure Proper, Volume Low.-
* Clogged Nozzle
OIL BETWEEN THE CRANKCASE AND PUMP MANIFOLD:
* Worn Plunger Rod Oil Seals
OIL LEAKING IN THE CRANKSHAFT AREA:
* Worn Crankshaft Oil Seal
* Bad Bearings
EXCESSIVE PLAY IN THE CRANKSHAFT PULLEY AREA:
* Worn Bearings from Excessive Belt Tension
OIL FROM UNDER THE CRANKCASE:
* Leaking Plunger Rod, Side Cover, Rear Cover, or Crankshaft Oil Seals Or O-Rings
LOUD KNOCKING NOISE IN THE PUMP:
* Pulley Loose on the Crankshaft
* Broken Or Worn Bearing, Connecting Rod, Or Plunger Rod
* Cavitation
FREQUENT OR PREMATURE PACKING FAILURE:
* Scored, Damaged, or Worn Plunger
* Overpressure to the Inlet Manifold
* Abrasive Material in the Fluid Being Pumped
* Excessive Pressure and/or Temperature of the Fluid Being Pumped
* Pump Running Dry
* Cavitation
HIGH CRANKCASE TEMPERATURE:
* Wrong Oil
* Low Oil Level
* Old Oil
* Contaminated Oil
* Oil Breakdown
WATER IN THE CRANKCASE:
* Worn Low Pressure Seals
* Cracked Plunger
* Worn Plunger Rod O-Ring
* Humid Air Condition
* Water Running Over The Pump
_
TROUBLE SHOOTING "QUICK" REFERENCE
PROBLEM POSSIBLE CAUSES REMEDY
Pulsation
Faulty pulsation damper
Check precharge: if low, recharge it or install a new one.
Low Pressure
Worn nozzle
Belt slippage
Air leak in inlet plumbing
Relief valve stuck, partially plugged or improperly adjusted valve seat worn
Inlet suction strainer clogged or improperly
Sized
Worn packing.
Abrasives in pumped fluid or
severe cavitation. Inadequate water.
Fouled or dirty inlet or discharge valves.
Worn inlet. discharge valve blocked or dirty.
Leaky discharge hose.
Replace nozzle, of proper size.
Tighten or replace
Use correct belt.
Disassemble, reseal and reassemble.
Clean, adjust relief valve-, check for worn and dirty valve
seats. Kit available.
Clean. Use adequate size. Check more frequently.
Install proper filter. Suction at inlet manifold must be
limited to lifting less than 20 feet of water or -8.5 PSI
vacume.
Clean inlet and discharge valve assemblies.
Replace worn valves, valve seats and/or discharge hose.
Pump runs extremely rough, pressure very low
Restricted inlet or air entering the inlet plumbing
Inlot restrictions and/or air leaks. Stuck inlet or
discharge valve.
Proper size inlet plumbing. Check for air tight seal.
Replace worn cup or cups, clean out foreign material,
replace worn valves.
Water leakage from under manifold; slight leakage
Worn packing.
Install new packing.
Oil leak between crankcase and
Pumping section
Worn crankcase piston rod seals O-rings on
plunger retainer worn.
Replace crankcase piston rod seals. Replace O-rings.
Oil leaking in the area of crankshaft
Worn crankshaft seal or improperly installed oil
seal-0-ring.
Bad bearing.
Remove oil seal retainer and replace damaged O-ring or seals.
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
May be caused by humid air condensing into
water inside the crankcase.
Worn packing and/or piston rod sieve, O-rings
on plunger retainer worn.
Change oil intervals, Use any high grade automotive 30
weight nondetergent oil.
Replace packing. Replace O-rings.
Oil leaking from underside of crankcase
Worn crankcase piston rod seals.
Replace seals.
_
Oil leaking at the rear portion of the crankcase
Damaged crankcase, rear cover O-ring, drain plug
O-ring or sight glass O-ring.
Replace cover O-ring, drain plug O-ring, or sight glass
O-ring.
Loud knocking noise in pump
Pulley loose on crankshaft.
Broken or worn bearing.
Check key and tighten set screw.
Replace bearing.
Frequent or premature failure of the packing
Scored, damaged or worn plunger.
Overpressure to inlet manifold.
Abrasive material in the fluid being pumped.
Excessive pressure and/or temperature of fluid
being pumped.
Over pressure of pumps.
Replace plungers,
Reduce inlet pressure.
Install proper filtration on pump inlet plumbing.
Check pressures and fluid inlet temperature; be sure they
are within specified range.
Reduce pressure.
Do not run pump without water.
Troubleshooting guide compliments of General Pump,
and Easy Clean Systems
