Need help diagnosing an old Speedaire compressor

[428street]

Hopefully someone can help with the problem I am having with my old SA AC. Thank you in advance.

A little history. I bought this from a friend of mine who upgraded his system about 15-20 years ago. I think he had it 10 years before me. I think it's a decent compressor (in it's day).

Recently he helped me replace a valve that goes from the tank to the top of the cylinder head on the engine. Don't remember the exact name of the part but I know it was some type of stop valve because the tank stopped holding air and there was a hissing sound coming from that tube area. This was replaced and the compressor has worked fine. I use it very rarely but as I am getting into doing body work and metal shaping I have bought some new air tools and started using it more.

The most recent problem is I went into my garage one random night and it was smokey. The compressor was on as it kicks on every once in a while to maintain tank pressor.

I walked over to the compressor and the top of the engine was smoking. I put my hand on the top of the cyclinder head and it was hot. It was not red hot but hot to the touch. I immediately turned the master power switch off that I have it connected too, open the garage door to let the smoke and and called it a day.

I then started looking for another compressor to replace this one but found out they are not cheap. So know I am searching for some help/direction in solving this problem and/or fixing the unit I have.

A couple days ago I put the compressor back on and filled up the tires on a couple of my vehicle and my snow blower and it was fine. The top did get warm but not as hot as it was when I initially encountered the problem.

BTW, my friend that has helped me in the past has become ill and can't help me anymore.

Any help, direction, advice would be appreciated. Good or bad. Thank you.

 

[Major Ramifications]

We would need to know where the smoke was coming from.

Also, as long as it works OK, continue using it but just remember to shut it off when you are done. If it starts smoking, try to pinpoint the source. The one thing you do not want to do is let the magic smoke out!

 

[428street]

Good question, the best I can tell the top of the head of the engine. I did not spend to much time as honestly I got a little nervous the thing was going to blow up as stupid as it sounds.

BTW, I also check the oil in the engine and it is up to level.

Agree on the shutting off and it's exactly what I have done last couple times. Is the head of the engine supposed to be hot during normal use?

 

[Bobcat753]

I have a horizontal tank Speedaire that has a similar if not the same pump. My pump does get hot on the head but doesn't smoke. You may try changing out your oil as there might be some water in it causing it to boil off and produce the smoke you see.

 

[The Tool Tyrant]

428, first, lets start off getting the terminology correct...what you call an "engine" is actually the compressor 'PUMP' and the electric device that powers it is a 'motor'. Normally, after a compressor cycles, the head is usually 'warm' to the touch. It it unusual to see 'smoke' from the pump, unless the belt is slipping, causing the smoke. Generally if you see smoke it would be from the motor, rather than the pump.
I suggest you check the belt tension first before going any further.

 

[428street]

Thanks for all the responses and more importantly not making me feel like an idiot. I love constructive criticism and I love to learn. This makes sense to me..the electric motor turns the pump via the belt that connects the two. The pump is what fills the tank. I will check this out for sure. How long does a tank/setup like this last? And I know there are a lot of factors that effect this but just trying to get an idea. There is a plastic guard that encapsulates the belt pathway. Going to remove that first so I can get a goo look-see.

 

[Stadger]

Just a guess but did you have a tool attached at the time? Something that let the tank drain down quickly so that the compressor was running a lot for a long time would heat it up to the point that the oil on the outside (see 3rd pic) would smoke.

 

[428street]

I did not sir.

 

[jakemac]

I think we first need to clarify a term. If I'm understanding you correctly, the part that you are referring to as an "engine" is actually the "pump". At first I wasn't sure if you were talking about the electric motor, or the pump. Edit - I see that Tool Fool beat me to it.

Both the motor and the pump will get hot with prolonged running. Even too hot to touch if running long enough. This is normal. The smoke is not normal. I suspect that for some unknown reason, the compressor was running for an extended period before it was noticed. Check for leaks in your line, or perhaps the shut-off valve malfunctioned. The smoke may have been excess oil on the pump burning off. Even with tight seals, there always seems to be oil seeping from somewhere.

As mentioned, I'd recommend turning the compressor off when not being used.
Keep an eye on it when it's running, just in case it's developing a real issue.
Otherwise, I think you're OK for now.

 

[428street]

Will do. And yes, there is a fair share of oil on the outside of the pump..I will try all above suggestions...can you please elaborate on the "developing a real issue"...Is there something I can fix proactively? Can I still get most of the parts for this? I also know I need to do further troubleshooting and figure out where and if the smoke returns.

 

[jakemac]

I'm certainly not an expert, but it could be possible that oil is getting past the rings on the Pistons and would need a rebuild. But I don't think you're there yet. You would notice the oil usage and see more oil in your air.

Keep an eye on your shut-off valve to make sure it's consistently shutting down when it's supposed to. That may have been a contributing factor to the overheating.

 

[Franz1.0©]

Lets begin with the FACT that is a superior machine to much of what is sold today.
If you go to wwgrainger.com and punch the 3z number into the search box you should be able to get the book on the machine. You may have to go to the repair parts section to get it.

Honestly, your description of the problem is a little wanting.
FIRST, you should not leave the machine powered when it isn't being used. Age has led to embrittlement in the tubing and that can develope into a nasty repair bill.
SECOND, and probably most important,
Power the machine down and check the oil level in the compressor.
If additional oil is needed, add it before moving ahead troubleshooting or using the machine. The oil for the machine is 30 weight Mineral type, NOT Synthetic, NON Detergent.

THIRD, WITH POWER OFF, check belt tension.

Probability is 80% the smoke was caused by a simple problem.

Second, you state the valve going into the "tank" was changed. You also say you hear air hissing from that valve.
At what point in the machine cycle do you hear escaping air and for what time duration?

Was any thread sealing compound or teflon tape used in the valve change?

 

[kams1973]

Did you notice the tank pressure when you shut it off? Did the safety/relief valve open causing the unit to run continuously?

Fran's--CH does have documentation approving Mobil1 in these pumps.

 

[428street]

@ Franz

Lets begin with the FACT that is a superior machine to much of what is sold today.
If you go to wwgrainger.com and punch the 3z number into the search box you should be able to get the book on the machine. You may have to go to the repair parts section to get it.

----------> Thank you.

Honestly, your description of the problem is a little wanting.
FIRST, you should not leave the machine powered when it isn't being used. Age has led to embrittlement in the tubing and that can develope into a nasty repair bill.

--------> Fair enough.

SECOND, and probably most important,
Power the machine down and check the oil level in the compressor.

-----------> This is one of the first things I did and oil level is fine.

If additional oil is needed, add it before moving ahead troubleshooting or using the machine. The oil for the machine is 30 weight Mineral type, NOT Synthetic, NON Detergent.

----------> Yes I have a bottle right next to the compressor.

THIRD, WITH POWER OFF, check belt tension.

------------> I will do this in the AM.

Probability is 80% the smoke was caused by a simple problem.

Second, you state the valve going into the "tank" was changed. You also say you hear air hissing from that valve.

-----------> "heard" which is what prompted the change of the value to begin with. No hissing sound now.

At what point in the machine cycle do you hear escaping air and for what time duration?

---------> Not sure how to answer this but right now there is no hissing.

Was any thread sealing compound or teflon tape used in the valve change?

-----------> From what I remember yes.

[/QUOTE]

 

[428street]

An update on my progress.

1. I decided just to drain the old oil and I went to the auto parts store and bought a quart of straight 30, says right on the bottle for air compressors. Drained the oil from the lower fitting and added new oil from the top fitting. I filled it to the top. Can anyone correct me right of wrong on this. I am going to buy the manual as suggested but don't have it now.

2. I took the back green plastic guard off the rear and I immediately saw that the belt was on the edge of the pulley on the electric motor and about half way off the groves on the pump motor. I was able to "adjust" the belt by hand but that might be the problem right there, maybe I am not supposed to be able to do that. I also see four bolts holding the electric motor and the pump motor which I assume I can adjust the angle of the pulleys if need be. I'm going to leave the guard off for now until I turn it on and see how things go.

3. The tension of the belt seemed OK but that is relative to me not know just how tight it should be. It's concerning I was able to adjust the belt without loosening anything up.

So right now just waiting for a response on the pump oil level then I'm going to fire it up and see if the belt stays straight on the pulleys and go from there. It's really made well and I'd prefer to keep it and even put some more money into it if I have too. When I buy the manual I will look for maintenance points and anything proactive I can do as well.

Thanks in advance. I've also attached some pics.

 

[428street]

The pics I took.

 

[jakemac]

The oil should fill to the bottom thread of the top hole.
Run the compressor for a bit, then check it again.

The belt tension should be a 1/2" of firm flex in the middle.

If you have a straight edge and a ruler, you can use them to check that the pulleys are in alignment.

I'd replace the belt soon. It seems that this may have been the cause of your problem.
The belt may have stretched over time and become loose, causing it to slip and move on the pulley. With a loose belt, the pump may have been slipping or not turning, causing the motor to keep running while it struggled to get the tank up to pressure. In the meantime, the motor pulley was spinning and burning up the belt, which may have flat or brittle spots on the grooves now.

I just replaced the motor and belt on my compressor, so I know how fussy it can be to get things lined up and tight.

 

[American Locomotive]

Multi-rib belts like that are supposed to be reasonably tight. If you could easily slide it over the grooves by hand, it's probably too loose. It's hard to tell, but it looks like the first few grooves on the belt might be burned off as well?

If so, the belt should probably be replaced. Unfortunately, since it's a multi-groove belt, your average hardware store might not have it. This might be an auto-parts store item.

 

[jakemac]

I bought my belt off of eReplacementParts or searspartsdirect. I can't remember.
IIRC, these were made by Campbell/Housfield. So that might be an avenue for parts.
Grainger should have them as well, since it's a Speedaire.
Tractor Supply ??????? Not sure.

 

[428street]

Roger that on the belt. I'll do a search online for the model number and find the belt. I've done zero to this in 20 years minus add some oil and the valve that was replaced about six months ago. It also gets very little use (in the past) and that is going to be changing as I'm getting into metal shaping and body work on my trucks...

 

[428street]

I've been on grainger and I put the model number in and nothing comes up. Went to parts as well, maybe I overlooked something. I did find a new compressor for a grand from granger though..

 

[jakemac]

Yea, that's how they get you.
The Grainger website is bad about support for older machines.
However, I found their customer support on the phone to be very helpful.
I needed a manual for my 30gal compressor and couldn't find it. The lady took the info and my e-mail address and said she'd call down to the archives. 3hrs later I had a PDF in my inbox. If they can find it, they'll send it to you. The problem is they didn't keep everything, and their filing system is bad. Their archivist needs to search for actual paper.

In general, I dislike Grainger and actively avoid them, but sometimes it can't be helped.

 

[428street]

More updates - lmfao!

Ok, so I went out and fired the compressor up, as soon as I did the belt jumped to the outside of both the pulleys. See pics. Also, the tube that connects between the tank and the pump got warm and this was only after maybe 30 secs or so. I did also take a straight edge and the pulleys appear to be lined up in-line with each other. So, definitely a belt replacement. I'll try eparts.

 

[428street]

Pics of the belts after I turned the compressor one, the new valve my buddy and I replaced, etc.

 

[American Locomotive]

Luckily, micro-v belts like the one your compressor uses are a very standardized thing.

Here's a good PDF on how to measure which type of micro-v belt you have based on the groove spacing: http://designcenter.gates.com/wp-content/uploads/2015/05/Gates-Belt-ID-Chart.pdf

You should also verify that the motor and compressor pump are square to each other as well, just not lined up.

Also. the compressor pump and discharge tube getting hot is normal. When you compress air, it gets hot.

 

[428street]

Thanks, I'm not having an easy time finding this belt, the model number I have must be very old 3z423e...I found a 3z424e but not a 423...I'll keep looking...

 

[The Tool Tyrant]

Even though you stated that the pulleys appear to be inline, I would be willing to bet that they're not and the fact that you can easily place the belt onto the pulleys is a good sign that the belt is too loose.

Did you have a close look at the belt for a part number?

 

[428street]

Ok, let me rephrase. I can't just stretch the belt and put back on the pulleys. I have to "slide" one grove over then I turn the wheel on the pump and I "encourage" the belt to get back in the correct groves on the pulleys. My take either way is the belt is too loose even to be able to do this. When I took the straight edge and lined in up with the inside groves of both the pulleys there did not seem to be any angle difference but I could have done it quickly plus the compressor is against the garage wall. I can turn it around perpendicular to the wall and see if I am missing something angle wise.

I did not check for a part number like a dummy that I am! the belt is spray green like the rest of the unit but I'll go check now. Thank you for pointing out the obvious. Dumb a$$ me.

 

[American Locomotive]

Thanks, I'm not having an easy time finding this belt, the model number I have must be very old 3z423e...I found a 3z424e but not a 423...I'll keep looking...

Take the belt, go to a NAPA, CarQuest, or some kind of industrial supply place (like Grainger), and tell them you need a J-section micro-v belt of the same length and number of ribs as the one you have now.

 

[The Tool Tyrant]

Try using acetone on a rag to remove the paint on the belt, if you're careful you may be able to just remove the green but leave the part number...worth a shot.

 

[American Locomotive]

Hold up. I found your issue. Your pump pulleys probably aren't lined up as well as you think. It appears that either the pump's pulley, or the entire pump itself has shifted backwards, which is why the belt keeps jumping out of the groove.

 

[The Tool Tyrant]

I now see what you spotted, quite interesting as it doesn't appear to have worn the paint from the pulley. I would also think that it would be making an obvious screeching noise.
Very interesting, and great catch A.L.

 

[428street]

AL, the next picture I was going to post was a close up of this as I just saw it myself...but here is an update from SA central. I loosened all four bolts that hold the electric motor down to be able to take the belt off which I did to measure and take a closer look for part numbers, when I went to tightened everything back up (four bolts) and I used a crow bar to keep the tension I found the rear bolt was stripped as I tried to tighten it down. I still got three good snugs on the three other bolts, turn the compressor back on and no belt shift anymore ...so....I have decisions...run it as is and see how it goes...retap for that one striped thread and do it right, buy a new belt? I physically checked the belt and it's not cracked at all anywhere...

 

[428street]

I can also loosen the pump motor and straighten it out and realign both pulleys as well. There is no sound at all coming from that area (where pulley and plastic case bottom are touching.

Only thing I am more concerned about is the feed tube (for lack of a better technical term) that goes from top of pump motor to top of tank gets warm/hot quickly after the compressor turns on. Is this normal? The tank does start to gain pressure as soon as the switch is turned on so doesn't seem to be a "clog" so to speak in that feed tub...please advise...

 

[American Locomotive]

I already said in my post above that compressing air makes it hot.

I would advise you to look at the pump shaft where it goes into the bug pulley. Make sure it's at the correct position and that the lock bolt is tight.

 

[dkroth]

Only thing I am more concerned about is the feed tube (for lack of a better technical term) that goes from top of pump motor to top of tank gets warm/hot quickly after the compressor turns on. Is this normal? The tank does start to gain pressure as soon as the switch is turned on so doesn't seem to be a "clog" so to speak in that feed tub...please advise...

Yes, that's normal.

I was doing some sand blasting this past summer - driving my compressor past its duty cycle. The top of the head near the output tube registered 315 F with my non-contact IR thermometer. Hot.

 

[428street]

You talking about this AL?

 

[md21722]

The line from the top of the pump to the tank check valve is called the discharge tube. It often runs 260-320F. Make sure the pump flywheel and motor sheave are lined up, adjust as needed, make sure the flywheel had sheave are fastened appropriately, and make sure the pump & motor are securely bolted to the tank top plate.

 

[428street]

Thanks to you md and ALL the responses. Greatly appreciated.

 

[American Locomotive]

Yes, that is the bolt. Make sure its snug, and that the pulley isn't walking backwards on the shaft.