# Craftsman air compressor



## Dexter6416 (5 mo ago)

Hello. So I got this oil free craftsman model #919165610 air compressor and it wouldn’t build over 90 psi… so I went ahead and changed the cylinders and rings and anything associated to that with new items. It builds over 90 psi now (I let it run until it got to 110ish and then turned it off because it took like 20 minutes to reach that pressure. The compressor is rated for 175 psi. Anyways does anyone have ideas on why it takes so long to build pressure? I heard that the copper wire needs to get super super hot but mine is fairly cool, it’s a little above room temperature. You can definitely hold on to it. I uploaded some pics if that helps at all..thanks in advance!!


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## JohnNY (Apr 27, 2020)

I think you mean to say you changed the pistons and rings?? But I also see some where the cylinder comes as a replaceable sleeve? Don't know the model number of that to look up. But either way if you did everything correct? Then you need to open up the air drain on the bottom and run the compressor with no air building for a break-in period of approximately 30 minutes I believe. Maybe able to download the manual for that? That will give you the actual time so the rings seat in the cylinder.


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## Dexter6416 (5 mo ago)

JohnNY said:


> I think you mean to say you changed the pistons and rings?? But I also see some where the cylinder comes as a replaceable sleeve? Don't know the model number of that to look up. But either way if you did everything correct? Then you need to open up the air drain on the bottom and run the compressor with no air building for a break-in period of approximately 30 minutes I believe. Maybe able to download the manual for that? That will give you the actual time so the rings seat in the cylinder.


i ran it for about 20-30 minutes building pressure. That should still break it in, no?


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## JohnNY (Apr 27, 2020)

Dexter6416 said:


> i ran it for about 20-30 minutes building pressure. That should still break it in, no?


Do that NOT building pressure is what is in all manuals. Guess it let's the rings seat properly


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## Dexter6416 (5 mo ago)

JohnNY said:


> Do that NOT building pressure is what is in all manuals. Guess it let's the rings seat properly


Ok I’ll go ahead and do it that. I also got a new check valve. It’s come to my attention that the copper tube aka discharged tube should be super duper hot. But mine is room temp so I’ll be cleaning that pipe and changing the dischard valve.


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## JohnNY (Apr 27, 2020)

Dexter6416 said:


> Ok I’ll go ahead and do it that. I also got a new check valve. It’s come to my attention that the copper tube aka discharged tube should be super duper hot. But mine is room temp so I’ll be cleaning that pipe and changing the dischard valve.


The tube from the head of the compressor to the tank will get extremely hot. Try not to keep throwing parts at it because you may be able to make a simple fix. Take the old valve out and check its function. Also does that compressor have reed valves on the head?there will be two above each cylinder, one for intake one for air going to the tank and should be seated perfectly to the head.


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## stevon (Mar 5, 2019)

Dexter6416,

With These "oiless" compressors there is no "break in" period, a new set of piston/cyl kit should be at 100% new and work it's way down to leaking. I have seen weak top pressure before when the head gasket leaks in between cylinders. The reed valves might also be leaking/broken. I would take the head off and look for problems there.

Stephen




JohnNY said:


> The tube from the head of the compressor to the tank will get extremely hot. Try not to keep throwing parts at it because you may be able to make a simple fix. Take the old valve out and check its function. Also does that compressor have reed valves on the head?there will be two above each cylinder, one for intake one for air going to the tank and should be seated perfectly to the head.


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