SL - Rexroth Hydraulic Power Unit - Filter - Replacement

Applies to machines built from: 
January, 1995

SL - Rexroth Hydraulic Power Unit - Filter - Replacement - Introduction

This procedure tells you how to replace the oil filter in the Rexroth Hydraulic Power Unit (HPU). Do this to prevent damage to the HPU pump and components caused by contaminants in the fluid, incorrect fluid flow, and low pressure. Do this procedure every 5000 hours of motion time, if the machine has low hydraulic pressure, slow tailstock or chuck movement, or if an Alarm 134 LOW HYDRAULIC PRESSURE occurs.
  1. HPU Oil Filter (Top View)
  2. HPU Oil Pump (Side View)


note: SL and ST lathes can have HPUs made by Haas, Parker, or Rexroth.
This procedure is for an SL lathe with a Rexroth HPU filter replacement. The Rexroth HPU is labeled and the filter is located on the side of the valve block.



Refer to Chuck and Tailstock - Recommended Maximum Pressure.

SL Lathe - Rexroth Hydraulic Power Unit - Filter - Replacement

Step 1

Push POWER OFF. Set the main circuit breaker to the OFF position.

Step 2

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

Replace the filter [1]. The filter is on the side of the valve block.

Step 3

Set the main circuit breaker to the ON position. Push POWER ON.

Push RESET two times to activate the HPU. Make sure the HPU operates correctly and has no leaks. Push ZERO RETURN. Push ALL.

Operate the hydraulic components. Make sure they have no leaks. Make sure the pressure is correct. Make sure the fluid level in the HPU tank is correct.

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.