If the body of your dump truck FAW CA3250, FAW CA3310 or another model in the series refuses to rise, the problem in 90% of cases is related to the hydraulic system or control electronics. The first thing you need to check is the pressure in the hydraulic pump: with the engine running and the lift mode turned on, the pressure gauge should show at least 18-22 MPa. If the needle barely moves or the pressure drops immediately after pressing the button, this is a signal about oil leak, worn cylinder seals or valve block malfunction. On models with electro-hydraulic control (for example, FAW J6P) low voltage protection may also be triggered - check the on-board network with a multimeter.

Another critical point is the position of the gear lever. On most dump trucks FAW the body is blocked from lifting if the lever is in neutral or a downshift is engaged. This is a safety measure, but often drivers forget to switch to D (Drive) or R (Reverse) before lifting. If all conditions are met, and the body still does not respond, proceed to step-by-step diagnostics - from simple to complex.

1. Checking hydraulic fluid and filters

The first step is to monitor the level and condition of the oil in the hydraulic system. On dump trucks FAW The power steering reservoir is usually located to the right of the engine (when viewed in the direction of travel) and has a yellow or red cap with markings HYDRAULIC OIL. The level should be between the marks MIN and MAX on the dipstick. If oil:

  • 🔴 Darkened or has metal particles → urgent replacement + flushing the system.
  • 🟡 Has a burning smell → pump overheating or radiator clogging.
  • 🟢 Clean, but the level is below normal → top up to the mark MAX (use oil HM-46 or HM-68 for FAW).

It is equally important to check hydraulic filter (located under the reservoir or on the supply line to the pump). A clogged filter leads to a drop in pressure and lift failure. On models FAW CA3250P It is recommended to change the filter every 10,000 km or once a year.

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If after adding oil the body rises jerkily, this is a sign air leak into the system. Bleed the hydraulics by opening the valve on the cylinder and turning on the pump for 2-3 minutes.

2. Diagnostics of the hydraulic pump and valve block

The hydraulic pump is the heart of the lifting system. On dump trucks FAW pumps of the type are most often installed CBG2040 or Parker P2. To check its functionality:

  1. Start the engine and turn on the lifting mode (lever to position UP).
  2. Place your hand on the pump body: if it vibrates a lot or heats up in 10 seconds, this is a sign of wear on the blades or bearings.
  3. Listen to the sound: grinding or whistling indicate a lack of oil or a clogged suction pipe.

The valve block (distributor) is responsible for directing the oil flow. On FAW it is usually mounted on the frame next to the lift cylinder. Signs of malfunction:

  • 🔧 Body lowers spontaneously → faulty check valve.
  • 🔧 Lifting occurs only when you hold the button → wear distributor spool.
  • 🔧 Oil flows from under the valve block cover → damage to the sealing rings.

Remove the pump protective casing|Check the oil level in the reservoir|Inspect the drive belt for wear|Test the pressure with a pressure gauge (connect to the test port)|Listen to the pump for unusual noises-->

3. Electrical part: relays, fuses, buttons

On dump trucks FAW with electrohydraulic control (series J6P, CA3310P) body lifting is blocked in the event of the following electrical faults:

  • 🔌 The fuse has blown F20 (10A) in the fuse box (located under the dashboard).
  • 🔌 Relay is faulty K3 (valve solenoid control). Check it with a multimeter: the winding resistance should be 70-90 Ohm.
  • 🔌 The contacts of the lift button on the remote control in the cabin have been oxidized. Disassemble the remote control and clean the contacts with alcohol.
  • 🔌 Broken wire between the control unit and the valve solenoid (often rubs against the frame).

For diagnostics use OBD-II diagnostic connector (located under the steering wheel). The scanner should show error codes related to hydraulics (for example, P1578 - low voltage in the solenoid circuit). Models up to 2018 may require FAW Diag or FawScan.

Mechanical lever|Electrohydraulic buttons|Pneumohydraulic system|Don't know-->

4. Lifting cylinder: leaks, play, jamming

The cylinder (hydraulic cylinder) is the most vulnerable element of the system. On dump trucks FAW Most often, cylinders with a diameter of 120-160 mm with rod stroke 1.2-1.8 m. Signs of malfunction:

  • 🛢️ Oil is oozing from under the cuffs → replacement is required sealing kit (article for FAW: WG9403100010).
  • 🛢️ The rod moves in jerks → corrosion or scoring on the inner surface of the cylinder.
  • 🛢️ The body rises crookedly → play in hinge joints or the rod is bent.

To check:

  1. Clean the rod and cylinder from dirt.
  2. Raise the body by hand (if possible) and inspect the rod for scratches.
  3. Check the fastening of the cylinder to the frame - the bolts must be tightened to torque 220-250 Nm.
How to remove the lift cylinder on a FAW CA3250

1. Disconnect the hydraulic hoses (place an oil container).

2. Unscrew the bolts securing the cylinder to the body and frame (you will need a 22mm socket wrench).

3. Carefully remove the rod from the bracket, avoiding distortions.

4. To replace the cuffs, use a puller (part no. T30001 for FAW).

5. Pneumohydraulic system (for models with pneumatic drive)

On some modifications FAW (for example, CA3310P6) the body is lifted through a pneumohydraulic booster. In this case, check:

  • 💨 Pressure in the pneumatic system (must be 7-8 bar).
  • 💨 Condition of the pneumatic valve (located next to the air tank).
  • 💨 Tightness of pneumatic lines (listen to the hissing of leaks).

If the pressure is normal, but the body does not rise, the problem may be pneumohydraulic converter (article WG9602100030). This unit converts air pressure into hydraulic valve movement. If it malfunctions, the body will rise very slowly or only when the button is pressed multiple times.

Malfunction Reason Solution Repair cost (RUB)
Body won't lift Low oil level Topping up/changing oil HM-46 500–1 500
Jerky rise Clogged filter or air leak Replacing the filter + bleeding the system 2 000–4 000
Spontaneous lowering Check valve wear Replacing the valve block 8 000–12 000
No response to button Relay or solenoid faulty Electrical diagnostics + relay replacement 1 500–3 000
Slow rise Pump wear or cylinder leak Pump repair or cuff replacement 15 000–30 000

6. Prevention and recommendations for use

To avoid problems with lifting the body onto FAW, follow these rules:

  • 🔧 Change the oil in the hydraulic system every 20,000 km or once a year.
  • 🔧 Check the oil level weekly (especially before long flights).
  • 🔧 Do not hold the lift button longer 10 seconds - this leads to overheating of the pump.
  • 🔧 Use oil in winter HM-32 (synthetic) for better fluidity.

Critical: Never lift the body when uneven loading (for example, when the load is shifted to one side). This creates misalignment and accelerates wear on the cylinder joints. On models FAW J6P the tilt sensor is triggered, which blocks lifting when the angle is exceeded 5°.

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Regular diagnostics of the hydraulic system FAW prevents 80% of breakdowns. The most vulnerable components: pump, check valve and cylinder cuffs.

⚠️ Attention: If you hear when lifting the body metallic grinding, stop the process immediately! This is a sign rod jamming or broken fasteners. Continued operation may cause the cylinder to break and the body to fall.

7. Frequent mistakes during repairs

Many drivers and mechanics make mistakes that aggravate the problem:

  • 🚫 Use of non-original seals (for example, from Volvo or Scania). Cuffs for FAW have a unique profile (WG9403100010).
  • 🚫 Bleeding the system without changing the oil. Old oil contains metal dust, which will quickly damage the new pump.
  • 🚫 Ignoring verification safety valve. It is triggered when the pressure exceeds 25 MPa, preventing hose rupture.

Another common mistake is incorrect adjustment of the rod stroke. On FAW CA3250 the maximum stroke is limited by a stop, which must be adjusted according to the instructions (see section 4.2 of the operating manual). If the stop is displaced, the body will not rise completely or will hit the stop with an impact.

⚠️ Attention: After replacing the hydraulic pump or cylinder, be sure to system calibration through a diagnostic scanner. On models with electronic control (for example, FAW J6P) without calibration, the body may rise asynchronously or with a delay.

FAQ: Frequently asked questions about FAW body lifting

Why does the body only rise halfway?

This is a typical sign insufficient pressure in the system or oil leaks in the cylinder. Check:

  • Oil level in the tank.
  • Condition of hoses for cracks.
  • Pressure with a manometer (must be at least 20 MPa when rising).

If the pressure is normal, the problem may be wear of rod seals — they pass the oil back into the tank.

How to bleed the hydraulic system after changing the oil?

Pumping algorithm for FAW:

  1. Fill in new oil to the mark MAX.
  2. Unscrew the bleeder valve on the cylinder (usually located on top).
  3. Turn on the pump (hold the lift button) and wait until bubble-free oil comes out of the valve.
  4. Tighten the valve and repeat the procedure 2-3 times.

Important: perform pumping when engine turned offto prevent air from entering the pump.

Is it possible to lift the body while moving?

No! On all dump trucks FAW body lift is blocked at higher speeds 5 km/h. This is a safety measure built into the electronic control unit. When trying to climb while moving:

  • The emergency shutdown of the hydraulic pump is triggered.
  • An error is recorded in the computer memory P1579 (“Unauthorized lifting”).
  • Increases the risk of the machine tipping over.
What kind of oil should I fill into the FAW hydraulic system?

The manufacturer recommends the following oils:

Model FAW Oil type Viscosity System volume (l)
CA3250, CA3310 HM-46 (mineral) ISO VG 46 22–25
J6P, J5P HM-68 (semi-synthetic) ISO VG 68 28–30
All models (winter) HM-32 (synthetic) ISO VG 32 —

Do not mix different types of oils! When switching from mineral to synthetic, flush the system with a special compound (for example, Liqui Moly Hydraulik-Reiniger).

Where can I find the hydraulic diagram for my FAW model?

Hydraulic diagrams are shown in repair manual (section Hydraulic System). Electronic versions can be found:

  • On the website official FAW support (enter VIN number).
  • In the database AutoData or Mitchell 1 (for service stations).
  • On owner forums (for example, AWD Forum).

For models FAW CA3250P and CA3310P The diagrams are also duplicated on a sticker under the hood (next to the hydraulic oil reservoir).