Bijur - Mechanical - Oil Pump Motor and Filter - Replacement

Applies to machines built from: 
January, 1989 to July, 2015
AD0353 Rev A

Bijur - Mechanical - Oil Pump Motor and Filter - Replacement

This procedure tells you how to replace the motor and the filter on a Bijur mechanical oil pump.

Machine Compatibility

Do this procedure on these machines:
  • Small and medium VMCs from 1989 to 2008.
  • Large VMCs from 1995 to 2014.
  • HMCs from 1994 to 2015.

Parts Included

QTY: 1
QTY: 1
QTY: 2

Bijur - Mechanical - Oil Pump Motor and Filter - Replacement

Step 1


Set the main circuit breaker to the OFF position.

Lock the main circuit breaker. Use an approved lock with an approved safety tag.

Step 2

Disconnect the oil hoses from the lubrication tank assembly. Plug the hoses.

Loosen the locknut [1] on the motor cable at the motor cover. Remove the motor cover [2] and the motor-cover standoffs [3]. This makes it easier to install the new motor.

Mark the wires that are connected to the used motor leads. Cut the leads from the used motor at the crimp connectors [4].

Remove the used motor.

Install the BIJUR OIL PUMP REPLACEMENT MOTOR [A]. Connect the ground wire [5]. Install the motor-cover standoffs.

Step 3

Strip the motor leads [1] to approximately 1/2" (13 mm).

Strip the leads [2] on the power cable to approximately 1/2" (13 mm)

Use crimp connectors to connect the motor leads and the power cable leads together.

Install the motor cover. Tighten the locknut on the power cable onto the motor cover.

Step 4

Remove the reservoir [6] from the tank lid assembly.

Discard the used oil and clean the reservoir.

Scrape the used gasket from the bottom of the tank lid and from the top of the reservoir.

Remove and discard the used discharge tube [2].

Remove the cannister filter cap [5], the o-ring [4], and the used filter [3].

Install the new filter [3], the o-ring [4], and the cannister filter cap [5].

Install the new discharge tube [2].

Install the new reservoir gasket [1] and the reservoir [6].

Reconnect the oil hoses to the tank assembly.

Step 5

Fill the reservoir to the MAX fill line [1].


To prevent build up of contamination, use Mobil SHC 625, Mobil 1 5W-20, or Mobil 1 10W-30. Do not use Mobil Vactra #2.

When you use Vactra #2, contamination ("sludge") collects in the reservoir. This causes the pump assembly to become clogged.

You must fill the reservoir tank to the MAX fill line [1] each time you fill the tank. This makes sure the dip trough [2] is full of oil. This lubricates the drive and worm gears [3] of the pump.

Bijur - Mechanical - Oil Pump - Test

Do this test after you replace a pump filter or pump assembly.

Step 1

Lift the plunger to hand-prime the pump. Do this until the pressure reads approximately 20 psi (1.38 bar).

note: If the lever arm [1] pushes up on the plunger, you cannot hand-prime the pump. Operate the spindle up to 30 minutes for the next pump cycle to complete.
In MDI mode, command the spindle to run at low speed, for example, 5 RPM.

This turns on the oil pump motor.

Stop the spindle when the lever arm drops.

Step 2

Disconnect the oil feed tube [1] from the fitting [3] above the canister filter.

Pull up on the plunger [2].

Oil comes out of the fitting [3] when the pump operates correctly.

Connect the oil feed tube. Do step 3 to check the oil pressure.

If no oil comes out of the fitting, refer to Mechanical Bijur Lube Pump Troubleshooting Guide.

Step 3

In MDI mode, command the spindle to run at a low speed, for example, 5 RPM.
note: The Bijur mechanical pump takes approximately 30 minutes to do a complete cycle.

Look at the oil pressure gauge when the plunger drops.

The oil pressure gauge shows 20 to 40 psi (1.38 - 2.75 bar). The pressure gradually decreases to 0 psi (0.0 bar) in 3-10 minutes.

Be aware: Many service and repair procedures should be done only by authorized personnel. The service technicians at your Haas Factory Outlet (HFO) have the training, experience, and are certified to do these tasks safely and correctly. You should not do machine repair or service procedures unless you are qualified and knowledgeable about the processes.

Danger: Some service procedures can be dangerous or life-threatening. DO NOT attempt a procedure that you do not completely understand. Contact your Haas Factory Outlet (HFO) and schedule a service technician visit if you have any doubts about doing a procedure.