kti hydraulic pump troubleshooting(Symptoms and Solutions)

Most likely, the selection of the best option from a variety of types of kti hydraulic pump troubleshooting will be difficult. After all, it is not easy to find out what entails good kti hydraulic pump troubleshooting. That’s why we want to give you some tips that should guide you in choosing the most appropriate kti hydraulic pump troubleshooting.

To troubleshoot Hydraulic Power Units you must first understand how the hydraulic circuit interfaces with electrical circuitry Also their order of operation per each hydraulic circuit. If you can understand these two things then most hydraulic systems can be fixed by you.

⚠️⚠️⚠️When working on a Hydraulic System Always Insure Hydraulic Lines have been depressurized. Hydraulic Injection can cause loss of fingers & even loss of life in severe cases. Hydraulic Injection can seem like a bee sting. If you are ever bitten by Hydraulic Injection go directly to the Emergency Room for Treatment.

Power Up Gravity Down (Circuit 103)

Extending Cylinder

Pressing the yellow hand control’s up key (not shown) provides battery power to fire solenoid and DC motor.

• Pressure is built as the gear pump PL-2.10 is rotated by this DC Motor 1245-15 which is turned on when start solenoid (not shown) gets activated.
• When fluid pass across this check valve LCV-08-P-0.3, it leaves through port “P” so that, cylinder can be extended.
• Fluid will bypass to tank when a cylinder reaches its limits of travel or maximum load. Primary Relief Valve set @ 3200 PSI and should not be adjusted unless drawing pressure adjustment instructions from factory’s technical support department.
• Factory Preset Relief Valve With Safety Wire Should Not Be Disturbed Or Warranty Becomes Void And Result In Severe Injury Or Death.

Retracting Cylinder

Providing power to coil on solenoid valve (LSV-08-2NCP) is achieved by pressing down button on yellow hand control(not shown).

• Opening a normally closed 2-way valve is done by activating solenoid in order to allow fluid to return back to the tank.
• (Optional) Flow control may be inserted into manifold so that cylinder retracting speed can be governed during fluid returning to the tank.

kti hydraulic pump Single Acting Wiring Diagram

Power Up Power Down (Circuit 111)

Extending Cylinder

Pressing UP Button on Yellow Hand Control (not shown) Provides Battery Power to Start Solenoid, DC Motor & Cylindrical Coil at the Same Time.

• Power is provided to DC Motor (1245-15) which turns gear pump (PL-2.10) to build pressure when Start Solenoid (not shown).
• When Cylindrical Coil (On LSV2-08-4CO) is activated, the Directional Control Valve (LSV2-08-4CO) shifts allowing fluid to travel through the Normally Closed 2-Way section of the Load Holding Valve (LSPC-08-4-00) & out Port A of Manifold which will extend cylinder.
• When the gear pump (PL-2.10) is building pressure to extend the cylinder the Pilot Operated section of Lowering Valve (LSPC-08-4-00) is piloted open to allow fluid from rod end of cylinder to travel back to tank. Pilot Ratio for lowering Valve is 2.5/1
• When cylinder reaches the end of its stroke or maximum load fluid will bypass to tank. Primary Relief Valve set @ 3200 PSI. Relief Valve is Factory Preset, Tampering With Safety Wire Voids Warranty and could result in Serious Injury or Even Death.

Orange is Fluid Traveling from the Gear Pump to the Bore of the Cylinder. Green is the Fluid Returning from the Rod End of the cylinder back to the Reservoir.

Retracting Cylinder

Pressing Down Button on Yellow Hand Control (not shown) Provides Power to Start Solenoid, DC Motor & Square Coil (on LSPC-08-4-00).

• The power is supplied to gear pump (PL-2.10) after Start Solenoid (not shown) has been activated and it is driven by DC Motor (1245-15).
• Pressure flows through Directional Control Valve (On LSV2-08-4CO) then through the Lower Section of Load Holding Valve (LSPC-08-4-00) out Port B of Manifold Retracting cylinder.
• When the Square Coil (on LSPC-08-4-00 is Energized Opening the Normally Closed 2-Way Section of the Lowering Valve (LSPC-08-4-00) allowing fluid to return through Directional Control Valve (LSV2 -8 – 4CO ) & back to tank.
• When cylinder reaches the end of its stroke fluid bypasses to tank via 2nd relief valve (RVSAE6 –30 ) set @ 1500 psi. 2nd relief valve is in place to prevent over pressurization of rod end of cylinder & thermal expansion

kti hydraulic pump Double Acting Wiring Diagram

kti hydraulic pump Low Voltage & Battery Issues

Low voltages leads to high current draw which results in increased temperature and decreased RPM in DC motors. Several occasions low voltage is actually a bad grounding situation. Starting solenoid contacts will have carbon deposits when the voltage drops, and this will damage the directional valve’s coils as well as cause resin on dc motor field windings to melt out (smell it & see the smoke when this happens).

Wrong wire size, poor connections, corrosion, auxiliary battery not being charged or blown fuse on charge wire may cause Low Voltage.

Trick: By attaching one end of jumper cables to the negative side of the battery & the other to the aluminum manifold, you can improve the ground condition. This is a fast way to check for poor ground.

Amps	< 5 Ft.	5-10 Ft.	10-15 Ft.	15-20 Ft.	20-25 Ft.	25-30 Ft.
100-150	4 Gauge	2 Gauge	0 Gauge	02 Gauge	02 Gauge	03 Gauge
150-190	4 Gauge	1 Gauge	02 Gauge	03 Gauge	04 Gauge	04 Gauge
190-250	2 Gauge	0 Gauge	02 Gauge	04 Gauge	04 Gauge	04 Gauge
250-300	0 Gauge	02 Gauge	03 Gauge	04 Gauge	04 Gauge	04 Gauge

kti hydraulic pump Relief Valve

Relief valves mainly prevent hydraulic systems from experiencing over pressurization, while in a double-acting circuit, the second relief valve will be installed after the check valve to prohibit thermal expansion or over pressurization of cylinder. This might culminate in disastrous failure.

Common Problems with Relief Valves

• Debris on the valve seat makes relief valves not to achieve maximum system pressure
• By tightening the adjustment screw fully, the spring will compress and crack prematurely or it won’t be possible to adjust it back to the specified pressure setting. (almost all safety valves will begin cracking 100-300 psi before full bypass)
• Torn or extruded O-rings

Check Valves

A check valve is similar to a relief valve but has a lighter spring allowing the fluid to pass through it with little pressure loss. In this guide, for hydraulic circuits discussed here, this relief valve is used in preventing pump-back of fluid.

Common Malfunctions of Check Valves

• Debris-caused sticking of the valve seat
• Torn or squeezed O-rings
• The growth of sand in the valve that causes poppet to jam

Normally Closed 2-Way

Nothing more than a solenoid operated check valve is a Normally Closed 2-Way. After the Solenoid (coil) has been activated, its pilot pin withdraws and the pressure equalizes on both sides of the poppet so that it can be retracted.

Common Problems with Normally Closed 2-Way

• Debris stuck on valve seat
• Torn O-rings on nose
• Silting – Debris buildup in valve causing poppet not to move freely
• Bent Stem on valve (Stem is the portion of the valve the coil slides over)

Directional Control Valve

The hydraulic fluid is just directed by what are simply known as Directional Control Valves. If we activate the Solenoid (coil) then the spool will shift leading to a change in flow path.

The tolerances between the cage and the spool are tight and over time these tolerances can increase leading to excessive leakage from the valve. In other words, with prolonged use, you may find that cycle times are increasing and eventually one will not be able to lift any load at all.

Common Problems with Directional Valve

• Electromagnetic coil not activating
• Over torqued valve (18ft-lbs. Max)
• Torn or extruded O-rings
• Debris stuck in valve
• Rust inside valve preventing spool from shifting
• Bent Stem on valve (Stem is the portion of the valve the coil slides over)

Ways to Check Directional Control Valve

Valve not shifting

• Ensure valve is not bent (stem is the section of valve the coil slides over)
• Remove valve from manifold
• Use dipstick on breather to push in section 1 on nose of valve. This will manually shift the valve.
• If you can’t shift the valve check for debris & or replace

Trick: By removing the white wire from the start solenoid you can place the coil back on the valve & shift the valve after it has been removed from the manifold. The valve should shift just as fast as you press the button if you see the valve hesitate to shift clean valve & try again. If problem persists replace valve

Valve stuck in activated position

• After removing valve check spool to see if it is covering the bottom half of the crossed drilled holes in section 2 of valve
• In the valves spring offset position valve should cover the bottom half of the crossed drilled holes on section 2 & 4

Load Holding Valve

The load holding valve checks both rod & bore end of cylinder, this valve is different than any other load holding valve. The solenoid (coil) operated portion allows you to retract the cylinder without having to add an orifice to restrict the flow of fluid down like you would with a dual pilot operated check valve.

Common Problems with Directional Valve

• Debris in check valves
• Bent Stem on valve (Stem is the portion of the valve the coil slides over)
• Air in system not allowing pilot operated check valve to open

kti hydraulic pump troubleshooting Symptoms and Solutions

Symptoms	Solutions
Not Building Pressure	1.Gear pump not priming D/A Remove relief valve operate pump for a few seconds until fluid comes out of port replace relief valve. S/A Same as double acting but remove check valve 2.Loose inlet on gear pump 3.Bad O-rings on relief valve or directional valve
Motor Not Running	1.Check Power to Start Solenoid 2.Check for Power to DC Motor 3.Check for Rust in DC Motor if a. & b. checked out ok
Cylinder Won’t Extend	1.Check Voltage @ Start Solenoid when trying to run Power Unit (Voltage May be below 9.5 volts) 2.Check to see if power unit is bypassing over the relief valve 3.Improper fluid in reservoir (viscosity to high) 4.Check Directional Valve Section D/A 5.Check Packing on Cylinder Section
Cylinder Won’t Retract	1.Check to see if coil on load holding valve is activating 2.Check Directional Control Valve D/A 3.Pilot operated check valve not opening D/A 4.Low voltage or poor ground D/A
Excessive Heat From Unit	1.Low Battery 2.Poor ground
Reservoir Overflows	1.Low Battery D/A 2.Poor Ground D/A 3.Air in hydraulic system 4.To small of reservoir
Struggles to Lift Load	1.Low battery 2.Poor ground 3.Gear pump sucking air 4.Directional valve half shifting D/A 5.Debris in relief valve
Start Solenoid Just Clicks-Motor Not Engaging	1.Carbon buildup on contacts in start solenoid 2.Rust inside motor 3.Loose wire from start solenoid to DC motor 4.Cracked housing on start solenoid
Start Solenoid Stays On	Low battery or poor ground caused start solenoid to weld on (replace start solenoid & check Battery & ground)
Won’t Lift Load (DC Motor Not Under Load)	1.Low fluid level 2.Loose inlet on gear pump (air being introduced into hydraulic System) 3.Gear pump not priming D/A Remove relief valve operate pump for a few seconds until fluid comes out of port replace relief valve. S/A Same as double acting but remove check valve 4.Worn out packing on cylinder
Cylinder won’t Retract Motor Under Load D/A only	1.Low Battery 2.Poor Ground 3.Coil on load holding valve not energizing 4.Directional control valve not returning to spring offset position 5.Bad packing in cylinder

If you can’t solve the kti hydraulic pump troubleshooting problem by yourself, please contact our professional engineers, we are very happy to help you!

kti hydraulic pump troubleshooting video

KTI Hydraulic Pump Parts list

The following is an alphabetical list of KTI Hydraulic Pump parts. Qualified mechanics, technicians and hobbyists use it to find out suitable replacement parts for their machines. In case you want to find correct machine parts, then you must be definite which part you are looking for or require. If you do not have a proper idea what you need, please call our customer service department at 1-866-616-3050 and we will provide with all help that you may need!

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kti hydraulic pump troubleshooting FAQ

If you have not yet installed a new kti hydraulic pump, you are in luck. This article has the information that you need to take to make sure that your kti hydraulic pump installation is successful and your future use of your kti hydraulic pump is trouble-free.