| Sympton | Possible Cause | Solution |
|---|---|---|
| Oil leak between crankcase and pumping section | Worn rod oil seals | Replace crankcase piston rod seals |
| Frequent or premature failure of the packing | Cracked, damaged or worn plunger | Replace plungers |
| Overpressure to inlet manifold | Reduce inlet pressure | |
| Material in the fluid being pumped | Install proper filtration on pump inlet plumbing | |
| Excessive pressure and/or temperature of fluid being pumped | Check pressures and fluid inlet temperature; be sure they are within specified range | |
| Running pump dry | Do not run pump without water | |
| Pump runs but produces no flow | Pump is not primed | Flood suction then restart pump |
| Pump fails to prime | Air is trapped inside pump | Disconnect discharge hose from pump. Flood suction hose, restart pump and run pump until all air has been evacuated |
| Pump loses prime, chattering noise, pressure fluctuates | Air leak in the suction hose or inlet | Remove suction line and inspect it for a loose liner or debris lodged in the hose. Avoid all unnecessary bends. Do not kink hose |
| Clogged suction strainer | Clean strainer | |
| Low pressure at nozzle | Unloader valve is by-passing | Make sure unloader is adjusted property and by-pass seat is not leaking |
| Incorrect or worn nozzle | Make sure nozzle is matched to the flow and pressure of the pump. If the nozzle is worn, replace | |
| Worn packing or valves | Replace packing or valves | |
| Pressure gauge fluctuates | Valves worn or blocked by foreign bodies | Clean or replace valves |
| Seals worn | Replace Seals | |
| Low-pressure | Worn nozzle | Replace with nozzle of proper size |
| Belt slippage | Tighten or replace with correct belt | |
| Air leak in inlet plumbing | Disassemble, reseal and reassemble | |
| Relief valve stuck, partially plugged or improperly adjusted valve seat worn | Clean and adjust relief valve; check for worn or dirty valve seats | |
| Worn packing. Abrasive in pumped in cavitation. Inadequate water | Install proper filter suction at inlet manifold must be limited to lifting less than 20 feet of water or 8.5 psi vacuum | |
| Worn inlet, discharge valve blocked or dirty | Replace inlet and discharge valve | |
| Pump runs extremely rough, pressure very low | Inlet restrictions and/or air leaks | Clean out foreign material |
| Stuck inlet or discharge valve | Replace worn valves | |
| Water leakage from under manifold | Worn packing or cracked plunger | Install new packing or plunger |
| Slight leak, oil leaking in the area of crankshaft | Worn crankshaft seal or improperly installed oil seal o-ring | Remove oil seal retainer and replace damaged 0-ring and/or seals |
| Bad bearing | Replace bearing | |
| Excessive play at the end of the crankshaft pulley | Worn the main bearing from excessive tension on drive belt | Replace crankcase bearing and/or tension drive belt |
| Water in crankcase | Humid air condensing into water inside the crankcase | Change oil intervals |
| Worn packing and/or cracked plunger | Replace packing. Replace plunger | |
| Loud knocking noise in pump | Cavitation or sucking air | Check water supply is turned on |
| Pulley loose on crankshaft | Check key and tighten set screw | |
| Broken or worn bearing | Replace bearing |
How to Choose a High Pressure Trigger Gun
The trigger gun is the part you hold all day, so it is worth getting right. Guns come in many designs and pressure ratings, and
