Air compressors are mechanical devices that compress air to provide a strong, steady flow of compressed air. They have many uses, from powering pneumatic tools to supplying breathing air. Over time, air compressors can wear out or break down. When this happens, a common question homeowners and automotive enthusiasts may ask is: can you rebuild an air compressor rather than replacing the whole unit?
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The Short Answer
The short answer is yes, air compressors can often be disassembled and rebuilt with new parts. Rebuilding a compressor may be cheaper than buying a brand new one. It also allows you to upgrade certain components like the pump, motor, or pressure switch. With some basic mechanical skills and the right parts, an air compressor rebuild is quite doable.
Reasons to Rebuild an Air Compressor
There are several good reasons you may want to rebuild an air compressor rather than junking it and buying a new one:
- Cost savings – Rebuilding just the worn components is often much cheaper than an all-new air compressor.
- Upgrade capabilities – When rebuilding, you can upgrade components like the pump, pressure switch, or motor.
- Customization – Rebuilding allows you to customize the compressor to your specific needs.
- Reduce waste – Rebuilding extends the life of the compressor and keeps it out of the landfill.
- Better reliability – You can rebuild using higher quality components than the original equipment.
Essentially if you have a compressor with a good frame, tank, and piping system, restoring those wear components can give it a second life. The cost to rebuild a compressor will vary based on what parts need to be replaced but is typically 50-70% less than replacement cost.
What are the Components of an Air Compressor?
To understand what rebuilding entails, it helps to be familiar with the main components that make up an air compressor:
- Compressor Pump – This is the heart of the air compressor. The pump compresses the intake air to the desired pressure level. There are reciprocating, rotary screw, and other types of compressor pumps.
- Motor – The motor powers the compressor pump. Electric motors are most common, but gas engines can also drive the pump.
- Pressure Switch – This switch monitors the system pressure and signals the pump when to start and stop compressing based on pressure demand.
- Tank – The air tank stores the compressed air. Larger tanks allow for longer runs of air tools.
- Safety Valve – This valve opens if overpressure occurs to relieve excess air.
- Check Valve – Check valves keep air from flowing back through the pump during the compression stroke.
- Gauges – Pressure gauges monitor tank pressure and compressor output.
- Piping – Piping directs flow to air tools or accessories.
The pump, motor, and pressure switch tend to be the components most prone to wear and most commonly replaced in a rebuild. But a full rebuild can also include replacing plumbing, valves, gauges, and other accessories if needed.
How to Rebuild an Air Compressor Pump
Rebuilding the compressor pump itself involves taking it apart, inspecting and replacing worn parts, and reassembling. Key steps include:
- Remove pump from tank
- Disassemble pump per manufacturer instructions
- Thoroughly clean pump housing and components
- Inspect parts – look for wear on bearings, rings, pistons, valves
- Replace any worn or damaged components with new OEM parts
- Reassemble pump with new gaskets/seals per manual
- Test pump for leaks and proper operation before reinstalling
The exact pump rebuild process can vary based on compressor model. Consult the factory service manual for your make and model for detailed disassembly and reassembly procedures. Pay close attention to any special techniques for tightening bolts or orienting components on reassembly.
Typical Air Compressor Rebuild Costs
The costs to rebuild an air compressor can range quite a bit based on the size, type, and what components need replacement. Here are some typical costs:
| Compressor Component | Typical Rebuild Cost |
|---|---|
| Compressor pump rebuild kit | $100 – $350 |
| AC electric motor | $150 – $500 |
| Gas or diesel motor | $300 – $1,000 |
| Pressure switch | $25 – $60 |
| Safety valve | $50 – $150 |
| Check valve | $15 – $70 |
| Gauges | $15 – $50 |
Keep in mind costs can run higher if there is damage to the compressor frame, tank or other components. The extent of the rebuild will also factor in. Small portable compressors can often be rebuilt for under $200 in parts. Large industrial compressors may cost $2,000+ to completely rebuild with new motors, pumps and accessories.
Factors to Consider Before Rebuilding
While rebuilding a worn out air compressor is almost always cheaper than buying new, there are some important factors to keep in mind:
- Age of unit – Rebuilding really old compressors may not be cost effective. The technology improvements of a new unit may be worth investing in.
- Availability of parts – You’ll want to be sure parts are still available for your compressor’s model before deciding to rebuild.
- Your mechanical skill – Rebuilding compressors takes some mechanical ability. If not DIY inclined, labor costs of a professional rebuild may reduce potential savings.
- Value of your time – Tearing down and rebuilding an air compressor can be a time-consuming project, especially your first time.
- Cost compared to new – Do the math comparing rebuild costs to a new model. At a certain point replacement may make more sense.
Carefully weighing these factors will help determine if rebuilding or replacing your air compressor is the better option.
DIY vs Professional Rebuild
You’ll also need to decide whether to rebuild the compressor yourself or have it professionally rebuilt. Here’s an overview of the pros and cons:
DIY Rebuild
- Pros:
- Less expensive
- Learn about how your compressor works
- Allows customizing the rebuild
- Cons:
- Significant time investment
- Need mechanical skills and tools
- Potential to cause damage if not rebuilt properly
Professional Rebuild
- Pros:
- Expert technicians do all the work
- Warranty on work performed
- Minimal time investment on your end
- Cons:
- Higher rebuild costs due to shop labor rates
- Less control over customization options
- May need to transport large unit to shop
For DIYers with mechanical competence, rebuilding it yourself can be a great option. But for those lacking the skills or time, the convince of professional rebuild may justify the extra cost.
Bottom Line
Rebuilding an air compressor rather than replacing it is usually much more economical. The key steps include:
- Disassembling the unit down to its components
- Thoroughly cleaning and inspecting parts
- Replacing any worn parts with new OEM replacements
- Properly reassembling the compressor
- Testing operation before putting back into use
While rebuilding requires some investment of time, money, and/or skill, it breathes new life into an air compressor for a fraction of replacement cost. Following manufacturer guidelines and taking care during disassembly and reinstallation will ensure your rebuilt compressor provides years more service.