What causes Haas alarm 803?

Low lubrication oil level in reservoir causing pump to cavitate or draw air instead of oil. Clogged lube line filter or metering valves restricting oil flow and preventing pressure buildup. Faulty lube pressure switch stuck open or calibrated incorrectly sending false low pressure signal to MOCON. Worn or failed lubrication pump unable to generate sufficient pressure to close pressure switch contacts. Broken or disconnected lube line causing oil to leak out before reaching distribution manifold and pressure switch.

How do I fix Haas alarm 803?

1. Step 1: Check lubrication oil reservoir level through sight glass and refill with Mobil Vactra 2 or equivalent way oil if low 2. Step 2: Navigate to Diagnostics > Inputs and monitor lube pressure switch state while manually cycling lube pump from Settings > Lube > Manual Lube 3. Step 3: Inspect all visible lube lines from pump to manifold for leaks, kinks, or disconnected fittings and repair as needed 4. Step 4: Remove and clean the inline lube filter element located between pump and distribution manifold, replace if heavily contaminated 5. Step 5: Jumper the lube pressure switch connector temporarily to verify switch fault versus actual low pressure condition, replace switch if alarm clears with jumper installed 6. Step 6: If all above checks pass but pressure remains low, replace lubrication pump assembly and verify output pressure reaches 50-150 PSI specification with mechanical gauge

axismd.ai

Haas Controller

System · Intermediate · 15-30 minutes

Alarm 803

Haas Alarm 803 - Way Lube Pressure Low

Haas 803 Lube Pressure Low alarm triggers when the lubrication system pressure switch detects insufficient pressure to properly lubricate spindle bearings and way surfaces. This alarm protects critical machine components by preventing operation when lubrication pressure falls below the minimum threshold required for safe operation.

HaasSystemIntermediate15-30 minutes

803

Haas Alarm 803 - Way Lube Pressure Low

Lube Pressure Low

Root Cause Summary

Haas 803 Lube Pressure Low alarm triggers when the lubrication system pressure switch detects insufficient pressure to properly lubricate spindle bearings and way surfaces. This alarm protects critical machine components by preventing operation when lubrication pressure falls below the minimum threshold required for safe operation.

Safety

Ways not lubricated

Causes and Fixes

1
Check Lube Oil Level
Open electrical cabinet and visually inspect the lube oil reservoir tank. Oil level should be between MIN and MAX marks on sight gauge.
Ensure machine is powered off and locked out before opening electrical cabinet.
2
Add Approved Lubricant
If low, add Haas-approved Way Oil (Mobil Vactra #2 or equivalent ISO 68 way oil) through the fill port until proper level is reached.
Use only Haas-approved lubricants to maintain warranty and optimal performance.
3
Cycle Lube System
Power on machine and allow lube pump to cycle. Monitor pressure gauge and verify 803 alarm clears after 30-60 seconds of operation.

DIY Feasiblehigh confidence

Call a technician if:

·Pump replacement required
·Electrical troubleshooting beyond basic checks
·Repeated failures after repairs

Prevention

Check lube oil level weekly
Replace lube filter every 6 months
Use only Haas-approved lubricants
Monitor lube system operation during daily startup

Common Mistakes

Using wrong viscosity oil
Overfilling lube reservoir
Ignoring gradual pressure loss
Not priming system after maintenance

Related Alarms

802 804 805

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