Atlas Copco XAS 185 Oil System: How to Check, Change, and Avoid Costly Failures
The oil system is critical to the performance and lifespan of your Atlas Copco XAS 185 compressor. Oil doesn’t just lubricate - it also cools and seals the screw element. Ignoring it can lead to expensive breakdowns and downtime. Here’s a detailed guide to help you check, maintain, and service the oil system with confidence.
1. Checking the oil level
Low oil level reduces cooling and lubrication, while overfilling can cause excessive oil carryover.
- Suggested action: With the compressor on level ground and stopped, check the oil level using the sight glass or dipstick. The level should be in the green range or between the min and max marks. Add oil only if necessary, using the recommended compressor oil type. After topping up, run the compressor for a few minutes, stop, and recheck the level.
2. Changing the compressor oil
Over time, oil degrades and becomes contaminated, reducing its ability to protect and cool the system.
- Suggested action: Change the compressor oil according to your maintenance schedule (often every 1,000 hours or annually). Drain the old oil completely when warm to ensure thorough removal. Refill with the correct oil type and quantity specified in your manual.
3. Replacing the oil filter
The oil filter removes impurities and prevents debris from damaging internal components.
- Suggested action: Replace the oil filter during every scheduled oil change or sooner if differential pressure indicates clogging. Always install an OEM-equivalent or approved filter to maintain proper flow and filtration.
4. Checking and cleaning the oil cooler
The oil cooler helps control oil temperature and prevents overheating.
- Suggested action: Inspect the oil cooler regularly for external clogging by dirt or debris. Clean it using compressed air (blow from the inside out) or a soft brush. Avoid using high-pressure water directly on fins to prevent damage. Keep the cooling system free of obstructions for consistent performance.
5. Inspecting the oil separator element
The oil separator removes oil from the compressed air before discharge. A clogged separator increases system pressure and reduces efficiency.
- Suggested action: Check and replace the separator element as recommended in the service schedule or if you notice increased oil consumption or carryover. Also inspect and clear the scavenge line to avoid oil build-up inside the separator housing.
6. Monitoring the thermostatic bypass valve
This valve regulates oil flow through the cooler to maintain optimal temperature. If it fails, oil may bypass cooling, causing overheating.
- Suggested action: Remove and inspect the thermostatic bypass valve if oil temperature is abnormally high. Check for sticking or debris. Clean or replace as needed to ensure proper function.
Final thoughts
Proper oil system maintenance is the backbone of keeping your Atlas Copco XAS 185 running reliably and efficiently. Checking levels, changing oil, and replacing filters and separators on schedule can save you costly repairs and keep you productive.