Air compressor maintenance

[rattle_snake]

I have a 1998 Campbell Hausfeld 60g/6hp air comp that is now struggling to build pressure. Found thermo protection tripped on motor. Observed cycle and it can't reach cut-out pressure and gets hot. Oil level ok, changed 2 years ago.

Compressor is a VT619502 with a VT470000KB pump.

I adjusted the cut in and diff pressures a few years ago. They had dropped with age, I cranked it back up to about 100/130 or so. I backed off cut-in to about 80 and tried adjusting diff screw but it still attempts to reach above 115 and can't. Hot, smoke out of dipstick vent. So I am just manually powering on for a single cycle as needed until repaired.

So what to do;
-rebuild pump, new pressure switch
-buy new/rebuild pump, pressure switch
-buy whole new compressor.

This unit does what I need, not looking for more CFM. Battery tools are replacing air tools. It's been powered constantly for 22 years, runs everyday, not bad.

If a rebuild, what is typically the cause of my problem? Valve plate assembly? Does it need to be disassembled and inspected first or can I buy a kit to hopefully shorten down time?

 

[nadogail]

In addition to valves, there may be piston rings involved. Not being familiar with your equipment, I can only make a blind guess.

 

[rattle_snake]

sure, thanks.

I didn't find a 'rebuild kit', but there are seal kits. Some parts are not available for this pump. I'm guessing I have to pull the pump (not fun to access) and take it apart for inspection. Some of the items are expensive, would take only a few things then a whole new pump starts to make sense.

Guess I will have to find a back up compressor and plumb it into system temporarily.

Looks like replacement pump is a VT4923/VT4723

 

[engineer2]

Would be easy to look at the condition of the valves. Is the thermal is tripping due to excessive run time or excessive Amps?

 

[Jking24]

If it's two stage inline it may have blew a head gasket and is bypassing internally. Ours at work does every few years. We just remake it out of gasket material and roll on. I'm sure if you wanted to wait you can get parts. By the way i don't recommend messing with the switch they can be very tempermental and a pia if you do not know the correct procedure for adjusting

 

[matt_i]

It looks like twin (parallel) cylinder but not 2 sequential stages to me based what I am thinking is the pump casting of equal sized cylinders.

https://www.ereplacementparts.com/c...ir-compressor-parts-c-32345_32346_178599.html

Also internal pump parts aren't available at least at that link.

I think I'd change the compressor itself.

 

[rattle_snake]

Would be easy to look at the condition of the valves. Is the thermal is tripping due to excessive run time or excessive Amps?

Yes I think I can take the head off the pump easy enough. I think motor thermo tripped due to excessive run time.

If it's two stage inline it may have blew a head gasket and is bypassing internally. Ours at work does every few years. We just remake it out of gasket material and roll on. I'm sure if you wanted to wait you can get parts. By the way i don't recommend messing with the switch they can be very tempermental and a pia if you do not know the correct procedure for adjusting

The 470000 is a single stage twin cylinder 135 psi 10 cfm.

It looks like twin (parallel) cylinder but not 2 sequential stages to me based what I am thinking is the pump casting of equal sized cylinders.

https://www.ereplacementparts.com/c...ir-compressor-parts-c-32345_32346_178599.html

Also internal pump parts aren't available at least at that link.

I think I'd change the compressor itself.

Thanks I think that is my plan at this point. I do like to rebuild and keep stuff out of landfill because I'm cheap, but I'm also too cheap to spend more on parts than a whole pump unit.

 

[DRP6833]

I rebuilt a Campbell-Hausfeld compressor a number of years ago. As I remember it wasn't that difficult. Unfortunately the tank developed pinhole rust a few years afterwards.

 

[astroracer]

My B.I.L. picked up a big compressor at an auction. Ran fine, the 80 gal. horizontal tank had a pinhole leak. I had him drill out the pinhole to thread in a 1/2" pipe plug. The plug and a bit of JB Weld and he is using his 10 dollar compressor.
Mark

 

[redmondjp]

My B.I.L. picked up a big compressor at an auction. Ran fine, the 80 gal. horizontal tank had a pinhole leak. I had him drill out the pinhole to thread in a 1/2" pipe plug. The plug and a bit of JB Weld and he is using his 10 dollar compressor.
Mark

Did you not see this thread?

https://www.garagejournal.com/forum/showthread.php?t=460702

What you described sounds extremely iffy, due to the minimal thread engagement of that pipe plug with the tank wall. After all of the reading I have done about pressure vessels, I would be very concerned about the safety of this repair.

 

[astroracer]

Did you not see this thread?

https://www.garagejournal.com/forum/showthread.php?t=460702

What you described sounds extremely iffy, due to the minimal thread engagement of that pipe plug with the tank wall. After all of the reading I have done about pressure vessels, I would be very concerned about the safety of this repair.

No, not really, we drilled it out past the rust so the plug is in good steel, tapped it and installed the plug.
There isn't that much pressure on the plug itself to cause a catastrophic failure. I think the compressor shuts off at 125 psi or so. 125 lbs per square inch of pressure means the small plug sees about half that. 60 or 65 lbs is not going to bother the plug at all. The issue with pressure vessels is catastrophic failure due to over pressurization and massive weld failure when ALL of the pressure is released at one time....
Mark

 

[dagofast]

Justin, Your tank is 22 years old. Before you spend any money on rebuilding/replacing the pump, you might want to look over your tank for a mfg. date and more importantly, a remove from service date. Campbell/Hausfeld does have them. Mine did.

I have a Campbell/Hausfeld from the same era that I replaced the tank on a couple of years ago. The replacement tanks are usually quite pricey but I happened to find a decent deal ($180) online for one. For not a whole lot more, I found a brand new Porter Cable compressor on sale at Tractor Supply for $299.

 

[rattle_snake]

mfg date is 1997, don't see a RFS date.
A whole new unit of similar specs is about $600. I think repairs would be about $300.
but yes, the motor is also that old.

 

[dagofast]

mfg date is 1997, don't see a RFS date.
A whole new unit of similar specs is about $600. I think repairs would be about $300.
but yes, the motor is also that old.

It might be worth a call to C/H to ask if your tank has a RFS guideline. Of course that's a bit like asking your barber if you need a haircut.

 

[Jswain]

If you're cheap you would feel pretty silly buying a whole rebuild kit only to find out you had a blown $5 gasket. I vote get a gasket kit or get ahold of some decent gasket material(garlock 3000 or equivalent specs) tear the head(or heads) off to inspect, flush out the case, clean everything well and assemble with new gaskets, new oil & hopefully thats all you need. If not you will know exactly which parts to get and the compressor should function as well as it currently does right now until they come in

 

[rattle_snake]

Thanks for the idea. Since it is still semi operational, I am taking my time and weighting options. I have another little compressor as a backup if needed.

 

[Wrench97]

Justin, Your tank is 22 years old. Before you spend any money on rebuilding/replacing the pump, you might want to look over your tank for a mfg. date and more importantly, a remove from service date. Campbell/Hausfeld does have them. Mine did.

I have a Campbell/Hausfeld from the same era that I replaced the tank on a couple of years ago. The replacement tanks are usually quite pricey but I happened to find a decent deal ($180) online for one. For not a whole lot more, I found a brand new Porter Cable compressor on sale at Tractor Supply for $299.

So I guess the tank on mine from 1934 would be no good even though the state inspects it every 2 years?

 

[LS6 Tommy]

My B.I.L. picked up a big compressor at an auction. Ran fine, the 80 gal. horizontal tank had a pinhole leak. I had him drill out the pinhole to thread in a 1/2" pipe plug. The plug and a bit of JB Weld and he is using his 10 dollar compressor.
Mark

Does he wear a $30.00 plastic motorcycle helmet with a visible seam, too? I wouldn't let my worst enemy run that rig.

Tommy

 

[dagofast]

So I guess the tank on mine from 1934 would be no good even though the state inspects it every 2 years?

There is a big difference in how an old industrial compressor was made and how modern consumer grade compressors are made. There is an even bigger difference in liability laws between 1934 and now too.

Does the state inspection include a hydro test?

 

[NilesRock]

You can get a rebuild kit for about $80 on Flea Bay. Another option is look around for a used compressor. About a month ago I picked up a monkey wards compressor with the same style pump for free. Those pumps aren't designed for a true 6 HP motor. I got a newer Cobalt 60G cheap off CL with blown pump and CH warrantied the pump. The new pumps aren't made as well as the old ones. The newer pumps have valves which are riveted in and can't be changed so stick with an older pump. That CH pump comes on Sears, Wards, Campbell Hausfeld, Dayton, Speedaire, and other brands. Use what you need for your tank and you'll have parts to spare.

 

[Ben Buck]

Check valve into the tank- might be going south !

Just my 2 cents ?

 

[nadogail]

IMHO, Your compressser is already broken, so any attempt to repair won't be a significant risk of making things worse.

I make this statement in complete ignorance of your skills and abilities.

My advice is guaranteed to be worth exactly what I am getting paid for it.

A little basic knowledge of fluid dynamics and physics will go a long ways towards a good outcome.

 

[NilesRock]

Here's a picture of the broken valve that was riveted in on the newer CH pumps.

 

[rattle_snake]

Thanks everyone for the feedback.
I have started to notice the odor of the pump's oil in the air system. There is also film of oil on tank around the dipstick vent indicating it has has blow-by for some time. Obviously I'm no expert but these 2 observations would lead me to believe that the rings/cylinder walls are worn. Rings are $50 and the jug is unavailable new.

If check valve at outlet was bad, I would assume it would leak tank pressure out of pump intake.

And although the motor is 'marketed' at a 6 hp, the nameplate would suggest otherwise. 2.98 kW is more like 4 hp by my math.

 

[Wrench97]

You usually don't see a ton of wear on the cylinder walls, it may be worth while to pull it down and inspect/rering it.

 

[Jswain]

You'll know how much is blowing by judging by the oil level in your compressor and how often you have to fill. I would not just assume that you need to rering. Especially running it like you are with it getting very hot because it is not cutting out and then it likely starts to blow by. My compressor does this when I am sandblasting running it 100% but normal air tool operation it is basically null and my cylinders look like brand new

I would rering if when you replace the gasket or valve that is broken/worn your fill rate is still slow when timed from 0psi to cutout. If after you replace your parts the calculated cfm is what it should be and you don't have to add oil very often your job is complete with the pump

 

[The Cobbler]

you could take the rings off the piston and insert them into the cylinders at various places to measure the end gap . not sure where you'd find the specs tho.

 

[rattle_snake]

Ok, I finally pulled the pump off for inspection. Gasket failure between cylinders

Evidence of cross-flow on valve assembly

Cylinder walls are worn. Not sure if new rings are a good choice here...

Since tank and motor are old I'm leaning towards repair and try to get some more life out of it.
gaskets $40

How difficult is ring replacement? Rings are about $40. I've built V-8s including piston ring fit/gap/install, but not a jug style install.

 

[zmotorsports]

Ok, I finally pulled the pump off for inspection. Gasket failure between cylinders

How difficult is ring replacement? Rings are about $40. I've built V-8s including piston ring fit/gap/install, but not a jug style install.

Justin, ring replacement isn't too awfully bad. It is very similar to an L-head Briggs & Stratton small engine. Most have a sump side cover to remove then unbolt the rod cap/bearing, push the piston/rod assembly out and pull the crank out of the output side of the pump.

 

[The Cobbler]

I would measure the end gap on the rings before you order them. to me, those cylinders don't look too bad, maybe a hone

 

[rattle_snake]

Justin, ring replacement isn't too awfully bad. It is very similar to an L-head Briggs & Stratton small engine. Most have a sump side cover to remove then unbolt the rod cap/bearing, push the piston/rod assembly out and pull the crank out of the output side of the pump.

No sump cover on this case. didn't find any videos how to rebuild.
Can one pull the jug/cylinders, pop new rings on, and re-install jug? Or does the rotating assembly have to come out?

 

[sberry]

If I can fix something like that for free I invest a little work in to it. If I gotta start buying many hard to find parts for it get more inclined to replace it.

 

[zmotorsports]

In that instance looks like just have to pull the cylinders and as long as bearings are in good shape no need to go into the bottom end.

Much like a motorcycle engine. Just stuff a rag or something in around the connecting rod to keep debris out of the crankcase. If the cylinders measure out ok, then just hone them and re-ring them.

 

[redmondjp]

In that instance looks like just have to pull the cylinders and as long as bearings are in good shape no need to go into the bottom end.

Much like a motorcycle engine. Just stuff a rag or something in around the connecting rod to keep debris out of the crankcase. If the cylinders measure out ok, then just hone them and re-ring them.

Yes, and just a very light honing to break the existing cylinder glaze - heavy honing and you can remove a few thousandths which will not be beneficial to a tight ring seal.

Those ball-stone hones with dozens of tiny abrasive balls on the ends of spring wire work very well, and good rental stores usually have them (so long as they have the correct size). Just one or two up-and-downs with a slow-speed 1/2" drill, leaving a 45 degree cross hatch, with some oil to lube it and it will be good to go.

 

[rattle_snake]

OK thanks mike, but how do I hot-rod this thing? Bigger motor pulley to increase pump rpm, head porting, shave jug to increase compression ratio, magic oil... Given it's old and tired, what could go wrong?

I ordered a gasket kit and rings for $57 delivered. The drive belt was comically worn out with pieces flying off once I had the guard off.

 

[rattle_snake]

Yes, and just a very light honing to break the existing cylinder glaze - heavy honing and you can remove a few thousandths which will not be beneficial to a tight ring seal.

Those ball-stone hones with dozens of tiny abrasive balls on the ends of spring wire work very well, and good rental stores usually have them (so long as they have the correct size). Just one or two up-and-downs with a slow-speed 1/2" drill, leaving a 45 degree cross hatch, with some oil to lube it and it will be good to go.

thanks for tip, I have a hone that should work.

 

[zmotorsports]

OK thanks mike, but how do I hot-rod this thing? Bigger motor pulley to increase pump rpm, head porting, shave jug to increase compression ratio, magic oil... Given it's old and tired, what could go wrong?

I ordered a gasket kit and rings for $57 delivered. The drive belt was comically worn out with pieces flying off once I had the guard off.

Justin, as for hot rodding, you could you could install bigger pulley and blend the ports but I'd add some bling. Use copper piping and polish them plus have the pulley cage/guard chromed. That would look saaawwweeeeeeett.

As we used to like to say when racing, "if it won't go, chrome it".

 

[nadogail]

My B.I.L. picked up a big compressor at an auction. Ran fine, the 80 gal. horizontal tank had a pinhole leak. I had him drill out the pinhole to thread in a 1/2" pipe plug. The plug and a bit of JB Weld and he is using his 10 dollar compressor.
Mark

IMHO, A better repair would have been weld a threaded coupling or flange into the tank and install the threaded plug into the female threads of the coupling or flange.

My opinion and advice are guaranteed to be worth exactly what you have paid me,

 

[engineer2]

I would lightly sand the head and the jug mating surfaces. Full sheet of sandpaper on a piece of thick glass works well. Not too smooth, the gasket has to grip the mating surfaces. http://www.leftlanebrain.com/cylinder-head-resurfacing/

 

[Jswain]

I would lightly sand the head and the jug mating surfaces. Full sheet of sandpaper on a piece of thick glass works well. Not too smooth, the gasket has to grip the mating surfaces. http://www.leftlanebrain.com/cylinder-head-resurfacing/

Agreed, then once back together break it in with a non synthetic oil and the drain valve on the tank fully open and run it for 30 mins, close the drain valve enough so it builds to 40psi run for 30 mins, then let it fill up and shut off. Some do a 3rd 30 mins @ 90psi

Change the oil to a synthetic after a few hours of run time, you can always look for the break in procedure for your specific unit but most are along those lines.