Attentions Before Operations:

1.Every hydraulic power unit is fully 100% tested before delivered. So when meet problem, contact ur tech support and don’t operate by yourself.

2.Target will not take responsibility for wrong installation and wrong application. Do not exceed the rated limits of the power unit or use the power unit for applications beyond its design capacity.

3.Do not operate the power unit without first reading and understanding the Operating Instructions.

To avoid personal injury or equipment damage, all power unit repair, maintenance and service must only be performed by authorized and properly trained personnel.

The operator must be familiar with all prohibited work areas such as excessive slopes, dangerous terrain conditions, and confined spaces.

Operator must start in a work area without bystanders, when dump trailer works, or hydraulic lift works.

4.Always disconnect the battery cable before attempting any repair. Do not inspect or clean the hydraulic pump or hydraulic tool while the hydraulic power source is engaged.

Disconnect both hydraulic hoses before attempting to clean or inspect the pump or hydraulic tool. Accidental engagement of the power unit can cause serious injury.

hydraulic power pack unit test bench

The hydraulic circuit control valve must be in the “OFF” position when coupling or uncoupling the hydraulic hoses.

5.Do not touch the motor and hydraulic parts directly. Wear gloves to protect your hand and wear goggles to protect your eyes.

6.Leave away and turn off the power pack immediately when you find any leakage.

7.Do not operate a damaged, improperly adjusted, or incompletely assembled power unit.

8.Be sure all hoses connections are tight. Supply hoses must have a minimum working pressure rating of 3000 psi/204 bar.

9.Carefully move the power pack, the valve will be broken if the power pack crash to the ground.




  • Check hydraulic power unit dimensions and mounting (vertical or horizontal) to meet proper installation space.
  • Read the operation instruction before installing valve. Proper valve installation is important to insure that valve will function correctly.
  • Check the O-rings of valves, and insure there is no foreign objects or contamination in valve and manifold cavity.
  • All O-rings must be lubricated on valve cartridge O.D. to insure that the O-rings can be installed into valve cavity without being damaged.
  • Insert valve into valve cavity And Hand Tighten valve into valve cavity.
  • Use torque wrench to tighten valve cartridge.
  • Over torque on valves could cause the cage of valve assembly to distort. Distortion could cause valve to not properly open and/or close, which could simulate contamination issues.
  • Failure to oil valves will cause O-rings to spin on valve assembly which could cause to O-ring slice length wise, cut or tear. Use Hydraulic fluid to lubricate O-rings, Do Not use any type of grease or motor oil. Grease or motor oil could cause valve failure when the hydraulic fluid mixes with foreign substance and gum up valves.

 Hydraulic Oil:

1.Check the cleanliness of oil before use.

2.Hydraulic oil can’t be higher than ISO 4404406/14. Hydraulic Oil should be filtered by 10-30um filter.

3.Normally suggestion the oil with ISO viscosity grades 32 and 46 (at 20℃-30℃).

  • If the temperature is too hot, you can choose the higher grades like 68.
  • If the temperature is too cold, choose the lower grader like 22 and 15.



The Hydraulic Circuit and Wiring Diagram will help you know the function of hydraulic power pack and help you to troubleshooting in your hydraulic systems.

Target Hydraulics fenggexian x1

Here are Hydraulic Central Manifold block inside oil flow ,it show us how the hydraulic fluid go through hydraulic pumps,

This hydraulic center manifold block show us a single acting hydraulic power pack application.

central manifold blocks,cartridge hydraulic valves,hydraulic cylinders and other hydraulic components .

Hydraulic cylinder-power-up-single acting power pack


When you press the “up” button of the Button remote or Wireless remote, the motor will turn on and the gear pump will get on work.

hydraulic gear pump

The hydraulic oil fluid will comes to into hydraulic gear pump  through the filter, suction pipe,  and then goes into the “P” port on central manifold ,inside of hydraulic reservoir tanks and  delivered to the Outlet port “P’  through check valve and normally closed (NC type) solenoid valve.

Hydraulic oil go through hydraulic pipes or hydraulic hoses reach cylinder,and hydraulic cylinder will extended drive by the high pressure oil from hydraulic power unit.

horizontal-mounting-hydraulic-power-units on assembly line

The solenoid do not work this time, and keep in a “check valve” state.

1.The check valve will stop the oil return to oil tank,so it also called a non-return valves, and keep the cylinder at current position.

If the check valve leak or get some problem, the Cylinder Won’t Hold Load or Cylinder Won’t Extend smooth.

2.The relief valve was set to a certain pressure (160 bar, 180 bar, 210 bar 3200 PSI relief valve, etc.), when the fluid pressure reach the setting pressure, the relief valve will work and the over pressure fluid will come back to the tank to keep the output pressure under a safety level.

So if the relief valve not set to a proper pressure, the hydraulic power pack can’t provide the right pressure even destroy hydraulic gear pump.

When press the “down” button of the button remote or wireless remote, the motor will be shuttle down, and the solenoid valve will work.

Turn to the “access” state, then with the gravity weight pressure, the oil will return to the T port (back to oil tank) through solenoid valve and needle valve (throttle).

At the mean time check valve still stop hydraulic fluid back to the Gear Pump P port.

Hydraulic cylinder-gravity-down

  • If the solenoid valve does not work, the Cylinder can’t drop down. If the solenoid get some dirty  problem, and can’t always stay in “access” state, the Cylinder  down will unstable.
  • The needle valve (throttle) is used to control the speed of cylinder down, if the needle valve too tight cylinder down speed will be slow, if the needle valve get loose the speed will get fast. But be careful, not lose too much, or the needle valve will leak and cause much noise and danger, the Cylinder will also coming down unstable. (So it is better to let the Target Hydraulics Engineers or Sales know your cylinder speed and not touch the needle valve by yourself.)

Target Hydraulics fenggexian x1

TroubleShooting list for hydraulic power unit:

English Version

  1. Oil tank, hydraulic hoses and fitting must be cleaned before installation.
  2.  Hydraulic oil can’t be higher than ISO 4404406/14. Hydraulic oil should be filtered by 10-30um filter. Suggestion: Oil viscosity – Summer HM32/46# or transmission oil – Winter HM22 or transmission oil.
  3.  Oil pump must be working with sufficient oil, oil less forbidden.
  4.  DC motor could not work continuously, please use it as duty circle.
  5. Change the oil after first 100 working hours. After that the oil change interval should be 1 000 hours.
  6.  Keep sufficient oil in oil tank in if not use for long time, please start device once per week.
  7. Battery most be full charge all time.
  8. Check tight wire connection for full power efficacy.

Manual Guide

1. When the oil inlet system can’t work or work unstable: Suggestions:

  • Oil tank was on short of oil, please add the oil to the required oil level.
  • Viscosity of the oil is too high, please use suitable viscosity oil.
  •  Suction filter was blocked, please clean or replace the suction filter.
  •  Solenoid valve was blocked, please clean the solenoid valve and clean the oil.

2. When the system drops unstable: Suggestions:

  • Solenoid valve was blocked, please clean the solenoid valve and change the oil.
  • Check valve was blocked, please clean.

3. The motor can work but the system can’t supply oil: Suggestion:

  •   Please check the filter and clean it or change the oil.
  •   When the DC motor does not work: Suggestions:
  • Check the remote control.
  • Check the solenoid switch / starter relay of the DC motor.

5. The power unit is not going down: Suggestion:

check on valve solenoid, a manual override turn counter clockwise will rise down immediately. It Have to be closed for power up.If Solenoid Valves without manual override then clean this solenoid valve in manifold block part.

Target Hydraulics fenggexian x1

French Version

  1. Le réservoir, les boyaux et les raccords doivent être propre avant     l’installation.
  2.  L’huile hydraulique doit être filtrée à 30 micron. Suggestion: Viscosité de l’huile  – Été: 32/46ou huile à transmission           – Hiver: 22 ou huile à transmission
  3.  Le système doit fonctionner avec la quantité d’huile nécessaire.
  4.  Le moteur DC ne peut fonctionner en cycle continu.
  5. Changer l’huile après 100 heures pour la première fois et ensuite par     intervalle de 1 000 heures.
  6.  Garder suffisamment d’huile dans le réservoir. Si l’unité n’est pas     utilisée régulièrement, veuillez la démarrer une fois par semaine.
  7.  La batterie doit être pleinement chargée en tout temps.
  8.  Vérifier la connexion du fil étanche une totale efficacité
Guide de dépannage 1. Quand il n’y a pas de débit d’huile, ou quand le débit est instable: Suggestions:

  •  Vérifier le niveau d’huile.         
  •  Vérifier la viscosité de l’huile.         
  •  Si la crépine est obstruée, la nettoyer ou la  remplacer.         
  • Si la valve du solenoïde est obstruée, nettoyer la  valve et l’huile

2. Quand le système de vient instable: Suggestions:

  •  Si la valve du solenoïde est obstruée, nettoyer la valve et l’huile.         
  • Si (Check valve) est obstruée, la nettoyer.

3. Quand le moteur fonctionne mais ne fourni pas d’huile: Suggestion:

    Nettoyer le filtre ou changer l’huile.

4. Quand le moteur DC ne fonctionne pas: Suggestions:

  • Vérifier la télécommande.         
  • Vérifier l’intérupteur du solénoïde du moteur DC.

5. Quand l’unité de puissance ne décent pas: Suggestions:

 Vérifier le bouchon de décente sur la valve du   solénoïde, ouvrir dans le sens de l’horloge. Le  cylindre va descendre. Fermer pour le remonter

For more details please contact Target Hydraulics Support Team

What kind of power unit design you offer?

Our Engineers use 3D and 2D software for hydraulic manifold blocks and hydraulic power unit system design. You can have free design help with your new inquiry.


What applications do your hydraulic power units have?

HPU’s Applications for a wide range include scissor lifts, electric straddle stackers, tailgate lifts,dump trailers, and so much more.

How many types of hydraulic power units do you offer?

ac/dc hydraulic power pack unit, double and single acting hydraulic power unit , etc

We are glad to assist you with customized hydraulic power units and hydraulic cylinders.

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