PM on Air Compressors?

[Ninjakitty]

Well, I wasn't sure where to post this one, but I was wondering what preventative maintenance should be performed on the compressor and other components of the air system.

All my lines look good and I don't have much water that comes out when I release the valve in the wet tank (accumulator tank?).

Everything seems to be working well except now the compressor squeals when she gets close to the 120 psi mark. Goes away when the PSHHHH (don't remember the name) happens. Something I can do to help this old beast? Or am I in the throws of death with my dear compressor?

Anything else, me or others should be doing or keeping an eye?

 

[Eclipse436]

Place a paper towel or cardboard under your air dryer (the thing that goes pshh) and see if its water or oil, same at your air tank drains. A little oil is fine but if it gets excessive it can Start to gunk up components. The air dryer itself has a filter in it, if you haven't changed it out yet i would for peace of mind.

Edit: have you checked your belt? The squealing could just be your belt slipping.

 

[Ninjakitty]

Place a paper towel or cardboard under your air dryer (the thing that goes pshh) and see if its water or oil, same at your air tank drains. A little oil is fine but if it gets excessive it can Start to gunk up components. The air dryer itself has a filter in it, if you haven't changed it out yet i would for peace of mind.

Edit: have you checked your belt? The squealing could just be your belt slipping.

I will check the belt again. Would it be from being old or being loose?

Will try the cardboard thing as well. Might as well change the filter, either way. No telling when it was changed. Thanks!

 

[Eclipse436]

Belt could be squeaking from being loose or being old.

 

[o1marc]

When mine was squeaking it was from no lubrication just before it spun all the bearings.

 

[Ninjakitty]

It's kind of a grinding squeal, hard to describe. Is there a lubricant that should be added to the compressor?

 

[Brad_SwiftFur]

Most compressors are lubricated by engine oil. If it's running dry, you'll want to make sure it's getting oil from the engine/oil pump. What's your oil pressure showing?

 

[o1marc]

It's kind of a grinding squeal, hard to describe. Is there a lubricant that should be added to the compressor?

It's pressure fed oil from the motor. That's what went on mine, no oil pressure, ran the pump dry and spun all the bearings. $300-$500+ to replace a compressor. They usually have a $500 core charge to deal with.
Grinding squeals are not good.

 

[Ninjakitty]

Most compressors are lubricated by engine oil. If it's running dry, you'll want to make sure it's getting oil from the engine/oil pump. What's your oil pressure showing?

Pressure gauge show that it's good. Over halfway.

 

[o1marc]

Pressure gauge show that it's good. Over halfway.

I'm still trying to believe the issue I had on that bus. I drove it 12 miles showing no oil pressure, then the pump blew. I drove it the rest of the way home with no variation in brake pressure or heat. So another 10 miles with no pump and no oil pressure. The next day it would start but build no brake pressure.

 

[Ninjakitty]

I found some used compressors that match my engine for about $275

 

[o1marc]

I found some used compressors that match my engine for about $275

I ended up finding a reman for the same price. Had a hard time returning it. They tried to say it was mounted so they wouldn't take it back. I said we took the bolts off the bottom plate and bolted it to my bracket, same holes same bolts. Never turned the pump. Took 2 months after I called their head office when I got a call saying they would take the return and scrap the pump, What a stupid policy. They had a good pump and my core which I didn't need back.

 

[Brad_SwiftFur]

Pressure gauge show that it's good. Over halfway.

Good, now check the oil line coming to the compressor and make sure oil is going through it (no obstructions).


A few may not have oil lines, but get oil from a more direct connection to the engine.

 

[Ninjakitty]

Good, now check the oil line coming to the compressor and make sure oil is going through it (no obstructions).


A few may not have oil lines, but get oil from a more direct connection to the engine.

Thanks. I will check that. Just a couple of lines in and out.

 

[WARGEAR]

An oil line will be braided most likely. It shouldn’t be plastic like the air lines coming off the pump. I hope your compressor isn’t toasted. Grinding noises in anything metal is not a good sign. Does it do it all the time or only when it’s almost built pressure to 120psi? Could be something else if it’s not constant.

 

[kidharris]

It's pressure fed oil from the motor. That's what went on mine, no oil pressure, ran the pump dry and spun all the bearings. $300-$500+ to replace a compressor. They usually have a $500 core charge to deal with.
Grinding squeals are not good.

Question



Is the compressor oil pump the same oil pump used to supply engine oil? If it is the same oil pump why didn't the engine burn up during the "no oil pressure" condition?

 

[o1marc]

Question



Is the compressor oil pump the same oil pump used to supply engine oil? If it is the same oil pump why didn't the engine burn up during the "no oil pressure" condition?

That has been what surprised me. I unhooked the oil feed line to the compressor. With the engine running there is no oil coming out the supply line, no pressure indicated on the oil pressure guage. I'm still trying to figure out how I drove 25 miles with no oil pressure, no increase in engine temp. A car or truck would have made all kinds of heat, noise, loss of power before it blew up before 5 miles. So you tell me?

 

[Ninjakitty]

An oil line will be braided most likely. It shouldn’t be plastic like the air lines coming off the pump. I hope your compressor isn’t toasted. Grinding noises in anything metal is not a good sign. Does it do it all the time or only when it’s almost built pressure to 120psi? Could be something else if it’s not constant.

Only when close to 120 and not everytime

 

[Ninjakitty]

It has two, braided lines, that I believe are for oil. I'll have to check for oil inside them

 

[WARGEAR]

That has been what surprised me. I unhooked the oil feed line to the compressor. With the engine running there is no oil coming out the supply line, no pressure indicated on the oil pressure guage. I'm still trying to figure out how I drove 25 miles with no oil pressure, no increase in engine temp. A car or truck would have made all kinds of heat, noise, loss of power before it blew up before 5 miles. So you tell me?

That is truly interesting! Perhaps splash lubrication kept the oil in the bottom end on the bearings and piston skirts.