# Air compressor: low psi



## cgrein (Jun 12, 2013)

Hey all,
I just purchased a used Brute, 15 gal, 125 psi upright air compressor, model #074003 for $25. I couldn't pass it up. The only problem is, it won't get above 30 psi. The motor keeps running, just won't get above 30. Any suggestions would be greatly appreciated.


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## joecaption (Nov 30, 2011)

Some cause can be the reed valves not seating, cracked, broken.
A leak in the line from the tank to the pressure switch.
Rings or cylinder worn out.


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## cgrein (Jun 12, 2013)

Thanks for your input. I know it's not a leak in the line to the pressure switch because when I shut the motor off, it maintains 30psi. Also, is it normal for air to come out of the breather while it's running?


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## oh'mike (Sep 18, 2009)

You are describing a bad set of reed valves---time for a rebuild---


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## joecaption (Nov 30, 2011)

If you order the parts to fix this make sure to order new head and reed valve block gaskets, (two different gaskets) also a new seal for the line that comes out of the head to the pressure switch.


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## beenthere (Oct 11, 2008)

Moved to Tools forum.


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## joecaption (Nov 30, 2011)

A leaking check valve can also cause air to leak out of the tank and out the breather.


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## cgrein (Jun 12, 2013)

Ok, after taking the head apart I think I may have found the culprit. There's a "V" shaped piece (not sure what it's called) that appears to be broken. Is this a reed valve you guys keep mentioning? Is it supposed to be in 2 pieces? Thanks.


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## joecaption (Nov 30, 2011)

Looks like a whole section is missing.


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## Maintenance 6 (Feb 26, 2008)

No, it's supposed to be one piece. I'd take a real close look at the cylinder wall and the piston. That broken out piece went somewhere. Almost hard to believe it didn't shatter the head when it broke. It could be lodged in the outlet port from the head. If the cylinder wall is scored or the piston is cracked, repairs may not be worth it.


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