Air Compressor rebuild

[olthumpa]

I have a Coleman Powermate Black Max air compressor, same as this one but with a 7.5 hp motor with a 100% duty cycle.
http://www.aircompressorpartsonline...h2c151b07z080v2c155-sanborn-parts-p-5155.html

Turn on is set at 145psi and cut off is set at 175psi and produces 26cfm at 175psi. Recently I have noticed that it is taking longer to recharge to 175psi than it used to. I have had this compressor for 18 years. I know that I can adjust the turn on/cut off pressures to buy me some time. I have never rebuilt a compressor but I do not think it would be that difficult.

My question, am I better off to replace the head or rebuild it? I know that it partly depends on what I find when I tear into it.

I am not in a hurry to due this and would like to put it off a while. It is still working OK but I want to get ahead of the game for when the compressor head can not supply the air I need. I want to have all my ducks in a row when I start this project.

All responses welcome.

Thanks in advance: olthumpa

 

[Tooljunkie]

If its not using oil or bypassing air into crankcase, then its just the head/ valves need service. Sometimes a cleaning and on rare occasions the vskes need to be flipped over.

 

[Lil Foot]

Maybe I'm denser than usual today, but what are "vskes"?

 

[skeets]

Yup I had to flip mine over as well, I also found that the drain valve on the bottom of the tank was leaking as well,,,, oh and trying to find parts for that is, wellll based on my experience with mine,, might be interesting,,

 

[Tooljunkie]

What? Cant read fat fingerese?
Sorry, was supposed to be valves.
After time they dont close tight.
Usually flat flappers,similar to a feeler guage blade.

Better to do it sooner than later.
Compressor running longer than it should.
Just makes it worse.

 

[olthumpa]

If its not using oil or bypassing air into crankcase, then its just the head/ valves need service. Sometimes a cleaning and on rare occasions the vskes need to be flipped over.

It isn't using any oil or bypassing air into crankcase. Thought it might be the valves but was looking for input from people with experience working on compressors.

I need to change the oil and filter soon so I guess I will tackle it then.

Thanks to everyone for your help.

olthumpa

 

[Lil Foot]

What? Cant read fat fingerese?

Thought I invented it, but obviously I need a refresher course.

 

[ipz2222]

"reed valves" Same thing as used in some 2 cycle motorcycles. It's just a flat piece of flexable metal that covers a hole and lifts up to let air in and closes to keep the air from moving the wrong direction. Most compressors have 2 valves in them. The tip can break off the valve or even half of it and it will still work but not as good as it used to. If yours is broke, you can make one from a metal can, not aluminum. It won't last as long as the original though.

 

[Tooljunkie]

Many times i have pulled the head and never damaged gasket.
Nothing to deal with other than the head itself.

 

[olthumpa]

Thanks for the additional information.

I had a 48 Johnson outboard with less than 20hrs on it when it sucked a reed into one cylinder blowing it apart and a part of the reed for the other cylinder badly damaging it. The fun part was that I was about 15 miles out in the ocean when it happened. Johnson replaced the complete engine, paid the tow/rescue charges and gave me a number of other items for my trouble.

 

[Tooljunkie]

Many outboard motors run non- metallic reeds, especially the performance engines. Just for that reason.