# Problem with MaxAir P4125H1-MAP, unloader valve



## MurrayB (May 19, 2021)

Hi, I would greatly appreciate some comments on my MaxAir 12cfm, 3.4 hp compressor.
The unloader valve screwed directly to the tank on this model: ndc29-m, seems unavailable or not made any more. Mine is shot, as a little o-ring seal inside fell apart, and now just dumps air...
Why would this design be chosen over having a simple check valve screwed into the tank with a feed off to a pressure regulator with an unloader valve?
Basically, I'm asking for thoughts on ditching the stock unloader, and going with a pressure switch/unloader combo.
Am I asking for trouble? Can it be converted? Compressor is only 10years old.

Desperate for thoughts and comments!

Thanks in advanced.

Murray


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## iowagold (Jan 22, 2020)

give these guys a call
MAXair P4125H1-MAP 3.2-HP 25-Gallon Belt Drive Cast-Iron Air Compressor
Call 1-866-437-8002 
i bet they can order the parts..
or just use after market parts.


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## stevon (Mar 5, 2019)

MurrayB,

I would replace it with another brand idler or Unloader or pilot check valve, you don't have to use the original part number. If you replace/change the original part with a pressure switch, that would change the design of this compressor which is built to run up to 100% duty cycle. With a regular pressure switch the most you can use any compressor is 50% duty cycle, 50 on 50 off. 

Stephen









Gas Air Compressor discharge Unloader check valve pilot valve combo 95-125 NG2 | eBay


Unloader valve (continuous run unloader) for gas & electric powered air compressors. They are used on both gas engine and electric motor compressors. 1/2" Female Pipe Thread SIDE Inlet x 1/2" Female Pipe Thread outlet.



www.ebay.com







MurrayB said:


> Hi, I would greatly appreciate some comments on my MaxAir 12cfm, 3.4 hp compressor.
> The unloader valve screwed directly to the tank on this model: ndc29-m, seems unavailable or not made any more. Mine is shot, as a little o-ring seal inside fell apart, and now just dumps air...
> Why would this design be chosen over having a simple check valve screwed into the tank with a feed off to a pressure regulator with an unloader valve?
> Basically, I'm asking for thoughts on ditching the stock unloader, and going with a pressure switch/unloader combo.
> ...


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## stevon (Mar 5, 2019)

or: GAS Air Compressor Pilot check valve unloader valve combo 95-125 NG7 | eBay


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