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Broken connecting rod in air compressor *PICS*

Johnnie

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Broken connecting rod in air compressor *PICS* Small engine experts?

Hey Guys-

Today I discovered my air compressor is broken. I removed the motor and discovered the connecting rod snapped in half. I looked up the part number and discovered it is available for order. I just wanted to check with the experts before I buy and replace it. From the research I did it seems like a lot of different compressor brands use the same motor because I found the connecting rod listed under Porter Cable, Makita, Dewalt, etc.

As you can see in the pics, the broken rod did a little damage to the cylinder from spinning around while the compressor was on. It also tore up the plastic motor housing. Based on what I see I'll just have to replace the connecting rod and and the cylinder.

Do you experts think this is all I have to replace? I'd hate to have to buy a new compressor because this one was given to me for free and I love it.

Suggestions before I order the part?

My broken parts.
DSCF1935.jpg


You can see the dented cylinder
DSCF1940.jpg


The motor
DSCF1939.jpg


DSCF1936.jpg


DSCF1937.jpg


This is what the new rod comes with.
KK-4964_parts.jpg
 
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Johnnie

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Ya, real cool noise. Actually I lent it to a neighbor because his compressor broke in the middle of a job and he needed one to finish painting He returned it 30 mins later telling me it needed oil because it was loud. I know it's loud but it was even louder. He either dropped it or it just happened to break while he had it and didn't tell me.

While I have the motor apart, is there anything I can oil or do to keep this "maintenance free" motor from being so loud? It's quite loud for being so small.
 

38Chevy454

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The noise is because it runs at high rpm. Oil-free compressor will always be noisy. Your options are to enclose in a sound deadening room. The thin alum case does not make as much dampening as the old thicker cast iron case. The lower rpm and higher thickness and mass makes the oil lubed style a whole lot quieter.
 

240sxguy

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I hate oil less compressors with a passion. I would take that as a sign that I needed to buy something less obnoxiously loud off of craigslist.
 
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Johnnie

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it was free so I can't complain. just need to get it fixed and running again.
 
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Johnnie

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I just ordered the part and hopefully I can get it fixed and running this weekend.
 
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Johnnie

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Well I replaced the broken parts and everything sounds fine. I ran the compressor and it won't go above 60 lbs. I tried a few different times and it won't go any higher. I took everything apart today to check any loose fittings but I didn't find anything. I turned it back on and it's having a hard time going part 60 lbs. The motor runs the same and doesn't slow down but the air pressure is just not getting high enough. I feel cool air coming out the vents which I'm assuming is from the fan but I also feel warm air coming out the other side but I'm not sure if that means anything.

Any suggestions other than getting a new compressor?
 

darcyh

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Perhaps the damage to the cylinder wall prevents the piston from developing any more pressure? Is it possible to hand sand the cylinder wall to remove the damage.

Regards,
Dave
 

pipsters

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If you replaced the piston and cylinder maybe it was damaged when reinstalled or maybe they are junky parts.
 
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Johnnie

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Perhaps the damage to the cylinder wall prevents the piston from developing any more pressure? Is it possible to hand sand the cylinder wall to remove the damage.

I replaced the cylinder so it's brand new. Initially I thought it has an air leak but it's hard to tell when I turn it on because the fan is also blowing.

Regards,
Dave

If you replaced the piston and cylinder maybe it was damaged when reinstalled or maybe they are junky parts.

The parts are identical to the original so I don't think they're junk. Everything seems to fit well. When I originally turned on the motor it sounded normal and I don't suspect and damaged parts.

Does the compressor have valves? Sometimes reed valves don't seal properly, especially if any shrapnel went through them.

I'm not sure if it has reed valves since I'm not very familiar with motors. I'll have to take it apart again to thoroughly inspect it. I really don't want to buy a new compressor because I know it's probably an easy fix.

Here is a layout of the motor.

I replaced 9 & 13, they were the broken parts. I had to remove 8, 6, 5, and 3 to replace the parts. The rubber gasket #8 is already mounted within #6. #5 is looks like lead and it's very soft and it's stuck to #6. I think it's called the gasket head. I insert the copper tubing #7 within #3 and close it all up.

#6 does have leaf valves so I'm not sure if that's a problem. Maybe they closed up too much?

3465GP3JR70PART2.GIF
 
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Johnnie

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No I didn't hone the cylinder. I guess I'll have to look into that.
 
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Greatbear

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Make sure the frame of the compressor isn't bent. It could be likely, given how the rod broke then slammed against the bottom of the cylinder. If the frame is bent, the piston won't come to full TDC, reducing output pressure.The piston should come up almost flush with the valve plate/head.
 

USMCdodge

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does anybody own the craftsman professional oiled compressor? is it reasonably quiet?
 

WV Hillbilly

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you don't hone the cylinder on this type of compressor, the cylinder is teflon coated, just insert the piston into it.
#6 is the valve plate, inspect it closely, also you might try spraying #5 with a good coat of paint on both sides, it seperates the intake & exhaust sides of the compressor, if it leaks, it can't make pressure.
 

98TJ

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does anybody own the craftsman professional oiled compressor? is it reasonably quiet?

I have a 60 gal Craftsman Pro. It's not bad. Worlds above the 30 gal Craftsman oil-free I had.

Considering the 60 was free, it's that much better.
 

Jbullfrog

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I had an oil free for 20 minutes when we lived in the city. 3 neighbors showed up and asked if I would be using that loud compressor often. I returned it and got a 25 gallon belt drive. It is way quieter.
 

USMCdodge

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I have a 60 gal Craftsman Pro. It's not bad. Worlds above the 30 gal Craftsman oil-free I had.

Considering the 60 was free, it's that much better.

so its quieter as in I could have a conversation within 15 feet of it?
 

Adam McLaughlin

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Someone gave me a free 60 gallon Craftsman compressor that was oil less... I thought it would be nice for painting.

It was REAL nice for collecting water in the air and then spraying a fine moisture mist out of my guns! LOL

Gave it away and got an old school dual stage oiled compressor. 27 CFM at 175 PSI. Doesn't mess around.

Adam
 
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Johnnie

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you don't hone the cylinder on this type of compressor, the cylinder is teflon coated, just insert the piston into it.
#6 is the valve plate, inspect it closely, also you might try spraying #5 with a good coat of paint on both sides, it seperates the intake & exhaust sides of the compressor, if it leaks, it can't make pressure.

I tried separating #5 from #6 but it's very soft and was about to tear so I didn't remove it. I'll have to reinspect it to see if it's torn. It's a very weird material. I looks like lead, feels like rubber and will tear apart very easily.

What would spray paint accomplish?

I'm going to take pictures some time this week and have you guys examine them in case I'm missing something.
 

98TJ

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so its quieter as in I could have a conversation within 15 feet of it?

You could have a conversation within 15 feet of an oil-less, too.

You'd just have to yell. :lol_hitti

Here's a video of the 60 gal fired up for testing. It was given to me. I was told that "it smoked and hasn't worked since." I cleaned the motor and fired it up. This video is from right on top of it. I have since cleaned the air filter and it's slightly quieter. I plan to add a belt tension adjustment bolt (it's missing the one that should be on it) and that should quieten it a tad more. Still need to change the oil, too.

http://www.facebook.com/photo.php?v=1867769551257
 
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USMCdodge

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I have the same problem with my compressor with the humidity here how do you keep the water from coming out of the air hose?is there something i can put on the air line? or the intake?
 
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Johnnie

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I removed the motor from the compressor to reinspect it. The only thing I found was a piece of shrapnel under one of the leaf valves. I'm not sure if that's the cause but it was a decent size that prevents that leaf from closing all way. I called around a few shops today and they suspect it might be the plate valve that has the intake and exhaust.

My compressor is stuck at 60 psi.
DSCF2209.jpg


Before taking apart
DSCF2210.jpg


DSCF2211.jpg


DSCF2212.jpg


Head and gasket side of the plate valve.
DSCF2213.jpg


The shrapnel was under the far right/bottom leaf pointing at the hole.
DSCF2214.jpg


Screwdriver pointing to the shrapnel. I'd guesstimate the shrapnel was about the size of the tip of a pen.
DSCF2218.jpg


Plate valve that goes against the cylinder
DSCF2215.jpg


DSCF2222.jpg


The rod pushed up against the cylinder
DSCF2216.jpg


DSCF2217.jpg


DSCF2220.jpg


And the broken fan that still works
DSCF2221.jpg


Anyone see anything that doesn't look right?
 
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Johnnie

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Head and gasket side of the plate valve.
DSCF2213.jpg


The shrapnel was under the far right/bottom leaf pointing at the hole.
DSCF2214.jpg


If you're referring to these two pictures, yes, the gasket is graphite so it's very sensitive. It's soft and will tear very easily.
 
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Johnnie

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I guess the only thing I can do now is replace the plate valve and gasket.
 

Greatbear

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While you are ordering parts, may I suggest a new fan as well. It will keep things cooler, and will not run out of balance to the point of killing the motor bearing. The fan is likely to shed more blades in its condition.
 

98TJ

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While you are ordering parts, may I suggest a new fan as well. It will keep things cooler, and will not run out of balance to the point of killing the motor bearing. The fan is likely to shed more blades in its condition.

This.
 
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Johnnie

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ill definitely replace the fan but right now I need air pressure.
 
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