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Air Compresor sounds weird, any ideas?

vmirv8bldr

Well Known Member
Last night I was working in the shop. My compressor reached it's low point, about 100psi and turned on. About half way through the charge, the sound changed instantly. It got louder, sounding more like an oil-free, but still nowhere near that loud. Near the end of it's charge, it started making an intermittent chirping sound. Just before shut-off, the chirping was constant. I tightened the belt and changed the oil, which seemed to help a little. After doing those and turning it on, it charged the full tank, from 0psi to 140psi with only one chirp. So I used the drill a bit. During the recharge it began chirping again, at about 135psi.

It is a Campbell Hausfeld 26-gallon oil-lubed 120V compressor.

Anyone know much about compressors?
 
There are intake and exhast valves in the head ... sounds like one of them is cracked.
 
vmirv8bldr said:
Last night I was working in the shop. My compressor reached it's low point, about 100psi and turned on. About half way through the charge, the sound changed instantly. It got louder, sounding more like an oil-free, but still nowhere near that loud. Near the end of it's charge, it started making an intermittent chirping sound. Just before shut-off, the chirping was constant. I tightened the belt and changed the oil, which seemed to help a little. After doing those and turning it on, it charged the full tank, from 0psi to 140psi with only one chirp. So I used the drill a bit. During the recharge it began chirping again, at about 135psi.

It is a Campbell Hausfeld 26-gallon oil-lubed 120V compressor.

Anyone know much about compressors?


It sounds like there might be a high pressure air leak from the head or head gasket or a valve cage (your compressor might not have a valve cage).
You can probably do a quick check by spraying soapy water, on the sealing areas, while it's chirping.
I know you've checked the oil........

Roy C Lewis Jr
RV8QB
AEIO-390 Catto
Jax, Fl
 
Yeah, changed the oil just to be sure. The level was fine before changing, but it was due anyway. I bought this about a year ago, with a three year warranty. I didn't use it at all from early December until June. So, there shouldn't be much wear and tear. Am I correct in thinking that this is more of a warranty type thing and not a regular maintenance thing?

(I know only CH can assess that in the end, but want to have a little knowledge going in to this before calling)
 
The "chirping" sounds like a belt slipping. The clue was that it happened as the pressure built up----------takes more torque to turn the pully.

Yes, I know you tightened it, but did you inspect to see that the belt isnt badly cracked, missing chunks, polished/shiney, or bottoming out in the sheave??

Also, check both pulleys are tight on their shafts------should be two screws at right angles on each. If you find a loose pulley, be sure to check the drive key and slots. The pulleys are softer than the shafts, and a LOT cheaper to replace.

May also be the reeds, but they usually ( in my experiance) make a continous noise when they go bad.

Good luck, Mike
 
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Belt Residue

When I pulled the cover off, I noticed a good bit of belt residue inside the cover. After checking, I noticed that this was much more prevalent on the motor end. Using a straight edge, we determined that it was not quite straight, and I attributed this residue to that fact. It came that way, I never double-checked it. Again, I haven't had this a year yet.

It's very difficult to see if the belt is bottoming out, but I will try to check that. The top of the belt is quite flush with the pulley on the motor side. If the friction was high, due to the alignment issue, the belt is likely quite worn. I will get a new one just to eliminate this area, and I will ensure the pulleys are straight this time.

I contacted a local Air Compressor shop. They also suggest troubleshooting the belt-pulley assembly first, as this is common problem. The tech there said the belt needs to be "Banjo Tight." He said he uses something similar to a bottle jack to get that tightness. Any other advice for tightening the belt while keeping it nice and straight?

Thanks,

*All helpers are entitled to a free beer. Not that commercial ****, either, GOOD beer. Just drop by the shop. :p
 
Banjos are for music!!

DONT!!

The bottle jack idea is very good for the repair shop, and very bad for your compresser. And your wallet. This will ruin your motor and/or compresser bearings in a hurry.

Align your pulleys with a straight edge, set the tension per the manuel-----usually about 3/4" mid way between the pulleys with a moderate one finger push----------yes, I know define "moderate"-----if it makes your finger hurt, you are pushing too hard.

V belts transfer torque on the sides of the belt, not the bottom. They need to sit snugly on the sides of the "V" of the pulley (sheave) and be in correct alignment. Belt width is important here--------too narrow is a big NONO.

Mike
 
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V-BELT dressing

Get a spray can of belt dressing and squirt it on the belt/pulley interface when the chirping occurs.
If it's the belt, the sound will change or go away.

-mike
 
mlw450802 said:
Get a spray can of belt dressing and squirt it on the belt/pulley interface when the chirping occurs.
If it's the belt, the sound will change or go away.
WD-40 will do in a pinch as a cheap and readily-available diagnostic tool. :D
 
REALLY tighten

When I got home I re-tightened it using a different method. No, not the bottle-jack. Baiscally loosen all four bolts, then pull as tight as possible with just hands, then tighten the outside bolt farthest from the motor pulley. Once it's tight, use a pry-bar to pull the pulley side over. I then tightened the remaining bolts.

One total tank fill and three recharges later still chirp free. Hopefully this will kill this thread, but it may serve useful for someone else.

FWIW, I did not use WD-40 or anything to troubleshoot, just gave it another shot.

Thanks to all who provided knowledge and/or experience.
 
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