bostitch wheelbarrow compressor not releasing pressure

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Old 12-18-14, 06:00 PM
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bostitch wheelbarrow compressor not releasing pressure

working on a cap6080wb compressor for a guy and have everything fixed exept the pilot valve is not working correctly. i have it set where it will cut off on 120psi, but the valve sticks when i first start it, i can manually work it once or sometimes twice and then it starts working correctly. part number is abu112. i took it apart and everything looked good on the inside and clean not sure why it isnt working. any ideas what to try?
 
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Old 12-19-14, 03:24 AM
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Could not find that pilot valve.....A picture might help.

I an familiar with a few pilot valves and I have never seen an adjustable one.
They were ordered with a specific release pressure.

Yours could be like this and if you made the release pressure higher it may be damaged or out of range.
Try moving the setting to where it was.
 
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Old 12-19-14, 04:18 AM
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What's a pilot valve or is that another name for a pop off valve?

As Greg said, pop off valves aren't adjustable although I have had them stick if the compressor was left on the back of the truck overnight when there was frost ..... but once it warmed up it would work correctly.
 
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Old 12-19-14, 04:26 AM
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Pilot valves are on gas engine driven compressors.

When the pressure rises in the tank the pilot valve senses it's preset pressure then opens.
The open port that has pressure from the tank operates a small air cylinder and closes the throttle on the gas engine taking it to idle speed.
Most pilot valves have a small opening that vents the low volume of air an idling engine produces.
 
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Old 12-19-14, 04:34 AM
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In my field of expertise a "pilot valve" would be an automatic valve that actuated another valve.

I'm wondering if this is an engine-driven compressor where the "pilot valve" would operate both an unloader valve and an engine throttle actuator. Or perhaps the OP is discussing the unloader valve that is sometimes part of a pressure switch that controls the electric motor.

Ah, it appears that it IS an engine-driven compressor. It also states the pilot valve is obsolete and no longer available. Maybe with some pictures of the actual compressor and a drawing or detailed explanation of how this pilot valve is plumbed I can offer some suggestions.

Bostitch CAP6080WB Parts List and Diagram : eReplacementParts.com
 
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Old 12-19-14, 04:42 AM
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Pilot valves are on gas engine driven compressors.
When the pressure rises in the tank the pilot valve senses it's preset pressure then opens.
Thanks for enlightening me Greg
 
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Old 12-19-14, 05:11 AM
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If the valve sticks it is possible that the adjustment you made could cause this.
If you are doing this for someone else you would do well to just replace it.

The last time I bought one it was preset to 100 psi and cycled off at 100 on at 85.
At one time 100 psi was where all compressors were set but lately makers are all over the place with where they preset the pressure.

There should be a lot of choices online for this.
 
 

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