# Kellogg American 2 stage compressor



## GZ

Last year, a buddy and I picked up an American Kellog 2 stage air compressor. Just got it back together and up and running but it is leaking down.

I have two hypotheses... 


The valves are failing and it is allowing pressure from the tank back into the cylinders. If this is the case, then it is just a matter of replacing the valves in the head. My problem with this hypothesis is that the air would have to be leaking down from the tank through two sets of valves (secondary and primary cylenders). Also, the crankcase is being pressurized. 

Something isn't connected properly... See the attached photo.

The line with the yellow circle is to equalize the pressure from the crankcase... I am 100% certain it is connected properly.

The second line (two red circles) I am not so sure of. It goes from the back side of the head to a junction block and from that junction block to the main block where I would expect the pressure relief valve to be. 

I think that tank pressure is being fed into the head from that line and then into the crankcase (via the breather tube)... I cannot, for the life of me, see a good reason to have that line there.

I am hoping someone who is more familiar with these compressors would be able to help me figure this out.

Thanks.


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## kbowley

*Re: American Kellog 2 stage compressor*

It looks like a head unloader. What is the model number and serial number of the pump...also, see if you can find a make/model of the junction block and/or the control switch on the motor, maybe the motor model/hp/rpms. What pressures does the unit switch off/on...is it consistant. What other line feeds into the the junction box that the white line connects to.

The issue is likely the unloader or the junction box valve.


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## GZ

*Re: American Kellog 2 stage compressor*

3HP/2500RPM/17A/220V

The switch is 145/175.

Don't know about the "unloader". Not sure what part you are referring to.

According to what I just read, there is no "unloader solenoid valve" on this compressor.


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## kbowley

*Re: American Kellog 2 stage compressor*

I need the model number of the pump...it should be on the crankshaft cover plate. Also, what other line feeds into that junction box that the line from the head goes to.


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## GZ

*Re: American Kellog 2 stage compressor*

It feeds to the main junction block... where the outlet/pressure gauge are mounted.

Can't do anything about the pump model ATM.


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## Basementgeek

*Re: American Kellog 2 stage compressor*

I would think it has some kind of unloader valve as you have to get the pressure off the heads when not running.

Crank case being pressurized? Sort of make since that maybe needing a ring job if the cylinders are holding pressure.

BG


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## kbowley

*Re: American Kellog 2 stage compressor*

OK, maybe you can get it tomorrow so we can proceed. I still think the unloader valve is not closing when the pump reaches full pressure and kicks off. You should hear a spurt of air, thats the unloader releasing the head pressure. It either located in the head or the junction box.

We'll be able to figure it out when I know what pump it is...kinda looks like a 335 but the head is different.


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## GZ

*Re: American Kellog 2 stage compressor*

There is no spurt of air when the compressor kicks off.

The cylinders remain under pressure. That is one of the reasons I believe the plumbing is off.

The compressor was in pieces when we picked it up. It is an older pump... 1960's??? I don't think the ID plate is intact.


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## GZ

*Re: American Kellog 2 stage compressor*



Basementgeek said:


> I would think it has some kind of unloader valve as you have to get the pressure off the heads when not running.
> 
> Crank case being pressurized? Sort of make since that maybe needing a ring job if the cylinders are holding pressure.
> 
> BG


The entire pump was rebuilt by myself and Keith. The valves were not replaced because they seemed to be operating properly.


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## Basementgeek

*Re: American Kellog 2 stage compressor*

Reed valves ?

BG


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## GZ

*Re: American Kellog 2 stage compressor*

The pump model is #331


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## GZ

*Re: American Kellog 2 stage compressor*

Here is the breakdown (parts list) of the pump unit. There is no mention of the unloader valve or solenoid valve.

There are three ports on the head. One on the top, above the outlet valve and one on the side just to the left of the outlet valve. The port on the top is capped and the one nearest the outlet port is connected to the pressurized line (from the main junction block into another block welded to the front of the tank then to the port next to the outlet).

The main junction block contains the outlet, pressure gauge, switch and the port I spoke of. In my experience and logic, that port should be used for a pressure relief valve...


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## kbowley

*Re: American Kellog 2 stage compressor*

Gavin, if your remove that line from the head, does air from the tank escape through it? I cant find a model 332 with that head on it, they all have the single intercooler line. That pump uses a centrifical unloader valve;

Product Specifications 

Delivers 17.2 cfm @ 175psi (5HP) 



For 3-5 HP motors
Cast Iron Construction
Slower Speed 345-668 RPM's for longer life.
Longer stroke to produce as much as the 335.
Steel Rods with Automotive Type Inserts and Needle Bearings at Wrist Pins
Positive Ring Fed Lubrication
*Centrifugal Unloading & Head Unloading*



[*]Bore: 4 3/4 LP & 2 1/2 HP. Stroke: 4"


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## GZ

*Re: American Kellog 2 stage compressor*

Yes. The line removed releases pressure from the tank and when running releases pressure from the head. 

Apparently the unloader is not part of the head assembly (like most newer compressors). I am unsure as to which head port would be the proper one to install it on.

Unfortunately I cannot find a description of each port, only the equalization port on the block and front of the head.

Part of the problem is that the compressor was aquired in pieces, without all the pieces there, so we were going by previous knowledge and our combined mechanical gut and instinct. 

We did a lot of research and have not been able to find any conclusive documentation on this pump and that is why I posted here!

I have included a ms-paint diagram of how it was (is) set up. I have Keith removing the Unknown line and capping both ports. This way he can test whether or not the valves are leaking down or if it was tank pressure feeding back through the system.


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## GZ

*Re: American Kellog 2 stage compressor*

Apparently, on most models similar to this the pressure switch (to shut the motor off and turn it on) was mounted in the top of the junction block located in front of the motor/pump. The new (NOS) switch is relocated to the top of the main junction box due to the size of the inlet (1/4 PIPE).

Also, where the switch is currently located is (apparently) where the emergency pressure release valve was originally located.

EDIT:

Also, looking into the centrifugal unloader... There is none on this pump. The capped end of the housing contains only the bearing housing.

I am almost positive that this compressor uses/used a pressure switch unloader.

Possibly the 332 (replaced the 331) incorporated the centrifugal unloader, but it is definitely not present on this pump assembly.


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## kbowley

*Re: American Kellog 2 stage compressor*

Hi Gavin...sorry, I crashed for a while. Anyway, I wanted to ask if that head has a hole on the top just above outgoing line or maybe opposite side thats plugged. I really need a bunch of pics to figure this out. I consider myself pretty good with this old iron but I am missing something. My email is [email protected]. try to take them at 1600x1200 or so, pictures of the hole machine from all sides, the top of the head, that junction box etc. 

I that helpful drawing, it shows that that single white line is the only thing filling the tank? In the jpg I cant see the inter cooler lines nor that junction box...in the drawing, the junction box has an outlet to nowhere coming out the bottom? I also see one large steel line going straight down but cant see its destination...tank or intercooler

This is what I understand as the issue. The compressor runs as it should and fills the tank faily quickly, shifts cylinders as it should (can you tell at what pressure it shifts over?) it starts and stops at 145/175. when the pump reaches high pressure and shuts down, air feeds back through that white plastic line, into the head and therefore the crank case and it then leaks out of the block somewhere and the unit loses pressure. is this correct? How fast does it leak down, can you determine where it is escaping the block, and how big is the tank? Take note of the the lines on the head in this pic









Thanks


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## GZ

*Re: American Kellog 2 stage compressor*

Nah, the inter cooler lines are on the other side of the pump (behind the drive wheel)... They are all there and accounted for.

I have already figured out that the original unloader valve was a pressure type and was integrated in the AC switch (which originally was mounted on the front block where the two grey lines meet). I can only assume, for now, that the port utilized on the side of the head (nearest the output) is the line that ran to the unloader.

I have Keith disconnecting the line for the time being and plugging the line that goes to the tank and putting a manual relief valve in the port. He hasn't gotten back to me on if the compressor was still leaking down.

From what I have gleaned from my research (aided by your insights) is that the original configuration is like the attached ms-paint diagram...

Since the unloading valve is not included in the current motor switch, I believe that I can make this work...

CONTINUOUS RUN COMPRESSOR UNLOADER,LGM40,145/175 PSI. | eBay


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## GZ

*Re: American Kellog 2 stage compressor*



kbowley said:


> I that helpful drawing, it shows that that single white line is the only thing filling the tank? In the jpg I cant see the inter cooler lines nor that junction box...in the drawing, the junction box has an outlet to nowhere coming out the bottom? I also see one large steel line going straight down but cant see its destination...tank or intercooler


The single line connects the crankcase to the head... See the breakdown from my second post...


kbowley said:


> This is what I understand as the issue. The compressor runs as it should and fills the tank faily quickly, shifts cylinders as it should (can you tell at what pressure it shifts over?) it starts and stops at 145/175. when the pump reaches high pressure and shuts down, air feeds back through that white plastic line, into the head and therefore the crank case and it then leaks out of the block somewhere and the unit loses pressure. is this correct? How fast does it leak down, can you determine where it is escaping the block, and how big is the tank? Take note of the the lines on the head in this pic
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Thanks


The pressure is escaping the block through the intake muffler and through the oil fill plug when it is opened. 

As for the lines on the photo you included, it only shows the one line... That is the side port, closest to the outlet. On the opposite side it runs to the junction block which is tied to the tank. There is no check valve... and I am pretty sure that the original pressure switch / unloader was located there...


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## kbowley

*Re: American Kellog 2 stage compressor*



















KELLOGG 331TV AIR COMPRESSOR 7.5 HP | eBay


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## GZ

*Re: American Kellog 2 stage compressor*

That compressor has a Centrifugal unloading valve setup... The one I have does not.

The centrifugal housing (at the back of the pump casing) is non existant... It is merely a bearing housing with the crankcase ventilation line.


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## GZ

*Re: American Kellog 2 stage compressor*

Also... The outlet shown on the bottom of the junction block in my illustration is where the valve is...


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## kbowley

*Re: American Kellog 2 stage compressor*

I understand, I was just showing how this one is configured, that outlet is designed to connect to some sort of an unloader. You could probably use a one way fitting at the outlet and it would be fine.


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## GZ

*Re: American Kellog 2 stage compressor*

Thats what I had figured... Did you look at the link in post #17? 

It would seem as though that would be the way to go at this point. (besides manual unloading)


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## GZ

*Re: American Kellog 2 stage compressor*

What about this....

PRESSURE SWITCH for AIR COMPRESSOR 4 WAY MANIFOLD 140-175 W/ UNLOADER H4 | eBay


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## kbowley

*Re: American Kellog 2 stage compressor*

Looks like that would be perfect.


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## GZ

*Re: American Kellog 2 stage compressor*

One last question... do you think we will need a check valve in the line?


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## kbowley

*Re: American Kellog 2 stage compressor*

The unloader shuold have a check valve that closes when the compressor side drops lower than the tank side. If not, you can always throw one inline.


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## ovalteen

*Re: American Kellog 2 stage compressor*

Hi guys thought I'd chime in. I'm Keith the owner of the compressor in question. Bruce (gavinzach) started this thread. Heres some info to clear things up. The compressor is a 1956 Model 331 Kellogg American (Brake Shoe Company). This model never had the centrifugal release like all the other models that you see (that big bulge off the crankcase). It was purchased in pieces and I had the internals inspected and the cylinders honed. I reassembled it with all new gaskets. When we put it together we had the fun task of putting this puzzle together with no directions or any good references to go by. I cannot for the life of me find a pic of another one of this particular upright model to even try to figure this out. Heres where I'm at as of today 3/21/12. I moved the pressure switch up to its correct location on the tank and plugged off where it was (a blow off valve we go in its rightful place.) I modified my pressure regulator to have an unloader valve on it that is activated as it should when the the pressure switch shuts off at 175#'s. The head is no longer incorrectly attatched to straight tank pressure. What happens now is the tank gets up to pressure fine with no leaks and then unloader valve kicks off but instead of a quick "pffffft" to unload the head, it just continuosly leaks down tank pressure. The crank case is still getting pressurized as well but not as bad as it was when it was plummed wrong. Im thinking I either have a bad valve or valves (these are diaphragm type valves) and the main tank line is backfeeding through the head down the pipe that goes to the unloader valve and down the vent pipe into the case, or I am missing a check valve somewhere in the plumbing that will keep the tank pressure from backfeeding. I've attatched a schematic of how everything is plumbed as of now. That blocked off port that Bruce showed on his schematic on the TOP of the head looks to have always been blocked off and never used. I didnt note it in my schematic. Thanks for your help.


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## GZ

*Re: American Kellog 2 stage compressor*

Ah... You finally posted! You have only had your account for a year! :rofl:

Welcome to TSF!!!!

I still think that we need to get the in tank check valve. I looked at a few local places but none of them had an online catalogue and it was too late to call them. If I wake up early enough tomorrow I will call before I go into work. Hopefully I can pick something up before I come up on Friday.

I need the measurement of the tank inlet opening so I know what size check valve to get.


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## kbowley

I would pull the head and double check the outlet valve...most units have a main output line to the tank and a small line off the main output going to the unloader/switch. There is only one way for air to back into the motor, through the output valve. However, I dont have pictures of your unit to see how you have it setup from the head to the tank. If the output valve in the head was closing as it should, tank pressure cant get back into the engine.

I am going to bow out as I cant be of much help without being there or a bunch of pics. 

1. I would double check the valves
2. I would put a modern electric control valve/unloader on it.
3. I am well versed in older compressors such as the Kellogg 
(I rebuilt a 335 last winter) but without seeing the way
its piped, its hard to picture what you have as they can be setup differently unit to unit.


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## GZ

The way it is piped is (reference the diagram in post 12)

The two intercoolers are connected to the proper connectors. (A on each outermost connector and B on the inner connectors).

The outlet is connected to the tank via the main feed line. (yellow line in ovalteen's diagram).

The side port (unloader port in all referenced cases) is connected to the unloader/switch.

The switch is connected to the tank via line to the main junction block.


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## kbowley

_"The switch is connected to the tank via line to the main junction block"_

Why would the switch be connected to the tank? It receives its information from the small line the runs to it from the head. Maybe its backfeeding there? Still, the output valve in the head should close like a check valve when the motor is not running. Hench, the reason for the head unloader, to drop head pressure and allow the main output valve to close.

Something is backfeeding into the head from the tank...for instance, if the junction box/switch is piped into the tank, that line is pressurized as well as the main line running to the tank. Maybe thats why the main output valve isnt closing...feedback from the small line isnt unloading the head to allow the output valve to close?

Try disconnecting the small line from the head to the junction box as it shouldnt be needed if the switch is connected directly to the tank. worth a shot.


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## GZ

No, I think you misunderstand... The feed line from the head is connected to the unloading valve. Tank pressure actuates the switch (to cut power at 175lbs) and to actuate the unloading valve.

We figured out why the pressure was backfeeding... The in tank check valve wasn't broken, it was jammed open with what appeared to be nesting material. I cleaned it out and lubed it up and it is working beautifully now. The unloading valve is releasing head pressure and no tank pressure is feeding back into the head.

The only issue we are having now is bad threads on the 2" bung on the front of the tank. I made the mistake of removing it to assist in flushing out sediment from the tank. I ordered a 2" NPT tap and will clean up the threads in the bung and the new plug should seal it up nice.


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## kbowley

Awesome Gavin! Glad to hear the 'ol girl is ready for another 50 years of service. Keep the oil changed and the air filter meticulous and it will last a lifetime.


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## SABL

Nice goin'!! I love the older equipment and have a few pieces in my garage (wood working stuff). Just make sure when you are chasing the threads you don't go too far with the tapered tap....and use some cutting oil.


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## GZ

I have grown to appreciate the quality and workmanship of older equipment. And also appreciate the look that comes with age.

This was definitely a score for ovalteen...


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## kbowley

Thats a nice clean job Gavin. Great machine...make sure the bottom of that tank is not rusted internally...
best.


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## GZ

You can thank ovalteen for the plumbing... He re did all of it last week. 

The bung was removed yesterday and all of the sediment was washed out of the inside of the tank. It has the normal rust on the inside but no major pitting. The steel plate is still in good condition.

Also had that 3HP motor apart for cleaning and inspection... for a 50 year old electric motor the windings and brushes are in excellent shape. I can see that motor going for another 20+ years, easily. 

If I am not mistaken, this compressor spent most of it's years in service in automotive shops and was taken out of service about a year before it was purchased by ovalteen. 

I am definitely glad to have been able to help with this. It was a great learning experience... And it is nice to know some of the terminology too... (unloading valve, etc :grin. Now both he and I have an intimate understanding of how the machines work and will have no trouble with upkeep. 

That pump will pressurize the tank from 0 to 175 in less than 3 minutes... and when running will keep the pressure steady with most air tools. The only thing left to get is the filter/regulator.


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## GZ

2" NPT tap came in yesterday (Friday). Successfully cleaned up the threads and installed a new plug with some RectorSeal... Letting it cure for 24. Let ya know how it works out. Should be no leaks now.


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## kbowley

Hi Gavin,

Glad to hear all is well...There really isnt anything like good old American craftsmanship, the things were made to last an adult lifetime. Just like a 70's era WheelHorse, darn near unbreakable with a heavy angle iron frame, solid cast iron transaxle with an 8 pinion differential and real bearings with balls in them. 

I own a small engine shop and although there has been some improvement in durability over the past 5 years, most anything priced less than 4k are made to mow a lawn and not much more with any longevity. Most any "garden tractor" made from 95-08 are pretty sad. a lot of plastic with very poor fit and finish, extremely soft hydro's and way over powered. I mean why put a 24 hp engine in a 8 inch wheeled mower with the lightest duty transaxle, a tuff-torq K46, thats only capable of delivering about 4 hp/200 inch lbs. of torque to the wheels. I can take my 12 hp '78 WheelHorse C-121 and hook them back to back and pull these 20 odd hp machines with no effort at all. There are still some standouts but they are pricey. The Simplicity Legacy, Prestige and Conquest are very stout. John Deere 500 and 700 series, The Cub 2500 series (the 3200 series was VERY stout but they discontinued it). Last year Craftsman sold a MTD made GT with a 9 gauge frame and a fabbed deck with a K-66 hydro for 2800.00, a real bargain but sears tractor attachments are horrid. They discontinued it for 2012 and sell only the Husqvarna, which is about the best value out there at 2500.00 with a good 54" deck but again, attachments such as plows, blowers, tillers are very poorly designed. Eastman industries in Portland Maine picked up the Case/Ingersoll line and they are a lifetime machine, the chassis is unchanged from the proven design of 1974. They are relatively reasonable @ 5500.00 for a 3016 with a 48" fabricated deck.

Ingersoll Tractors link

I'll stick with my WheelHorses, heck I have about 30 of them as well as a couple Bolens HT's, a 04 Simplicity 4x4 legacy and a few Ariens GT 20's and 4 Ariens YT 12's (8 inch wheeled but weight 650 lbs without attachments and a dual motor serviceable Eaton 750 Hydro. The manual shifts have high/low range, these are VERY tough all steel little buggers) with 42" front blades and 36" dual stage blowers. I just love a real Amercan made product. Ya dont see to many PeterBuilt trucks in China:whistling:


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## cj2025

Hello All,
So I found this forum while trying to search out the answer to a question I have had. I picked up one of these old Kellogg's from a shop that had been using it for many years. It has a 2 year old 5hp Baldor motor 220/1 and I believe it is a 331 Kellogg pump, although it has no model plate or anything else. My question is that the unloader valve for the centrifugal pump is not hooked up. Apparently they have been running it this way for years without any issues. I actually powered it up and it ran quite fine, built up to 150psi and cycled on again when it reached 90psi. The weird thing about the model I have is that it does not have an unloader port. Not under the head next to the inercooler lines or on the sides anywhere. I have check and re-checked over the past few days, nothing new appeared on any given day. So....would it be reasonable to plumb the centrifugal unloader connection into the exhaust line to the supply tank, up close to the head? Hopefully I'm making sense. I will post pictures for clarity. This model has a 3 grooved flywheel. Thanks!


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## fordever55

I acquired a Kellogg compressor, model 331TV 258. My question is on pressure switch there are two fittings beside each other one has 1/4" line going to the tank the other fitting the 1/4" line is missing. On side of compressor there is a port with line going into top of port but on the bottom its threaded and air leaks small volume, is this where pressure switch line is to attach ? Thanks


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## cj2025

Can you upload some pictures of your compressor and pressure switch so we can have a visual of your setup? In my case the pressure switch is plumbed to the pump outlet line and unloads the head from there. The pump body uses a centrifugal unloader in order to normalize the internal pressure when the pump stops working. I was initially confused by the open connection from my pump unloader port but then I discovered that since the addition of a pressure switch which unloads the high side of the pump it no longer needed to be connected. Your problem sounds different from mine and visuals for me always speed up the process.


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## fordever55

My cell phone won't upload like that but I can share to email or text


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## cj2025

ok ill send you an in-message.


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## gjewers

Hello, If anybody is still interested in this thread, I am looking at a 1985 Kellogg 332 compressor. The current owner has seen it run in the last year but it is not hooked up to power now. It was in an old auto shop and used for tools and a hydraulic/pneumatic car lift. It leaks some oil from one of the two lines from the top of the head to the crankcase as there is a drip cup attached. Is there any way to check this machine without actually running it?
It comes with 2 120 gallon tanks. They are asking $1,500 for it. What do you think of the price if it were to be in OK shape? I will only be using this on occasion to blow old steam whistles and not for everyday continuous service. I need the high pressure and the volume and have not found anything else currently offered that is less than "industrial". Any info would be appreciated. Thanks. greg


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