# Vintage air compressor



## OPA1973 (Jun 28, 2021)

New to this forum. I recently picked up an old Montgomery Ward air compressor which has had both the electrical motor and compressor pump replaced at some time. I am looking fir help identifying the pump so I can order repair parts. Attached are photos of the pump. Cannot find any name tag. Found a “patent applied for” cast in the housing and a serial number stamped on the side. Thanks in advance fir your help,


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## 68Futura (11 mo ago)

OPA, you may have figured it out by now, but that is a Brunner model A-500 pump. It requires a 3/4hp motor, and has a max RPM of 675 rpm. Based on the design of the crank case casting, I'm guessing this unit is from the 1970's.


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## stevon (Mar 5, 2019)

OPA1973,

Why rebuild? sentimental value? you can buy new cylinders for $100 more or less. Is the tank rusty? Would recommend a hydrostatic test of the tank to be sure it's safe if there is a ton of water in the tank or if the tank body is very rusty. You can google on how to safely test an air tank.

Stephen


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## 68Futura (11 mo ago)

stevon said:


> OPA1973,
> 
> Why rebuild? sentimental value? you can buy new cylinders for $100 more or less. Is the tank rusty? Would recommend a hydrostatic test of the tank to be sure it's safe if there is a ton of water in the tank or if the tank body is very rusty. You can google on how to safely test an air tank.
> 
> Stephen


When you say new cylinders for $100 more or less, do you mean a new pump? 

One reason may be, and I forgot to mention this earlier, these Brunner compressors are very durable and well-built units. Brunner was one of the largest manufacturers of compressors in the world. They introduced this design in the mid 1930's, and many are still running today. This model was even used for refrigeration aboard naval ships during WW2. I have quite a few of them, a 1958 that I use every day. Compared to any modern reciprocating compressor, these compressors are quiet and can run indefinitely without overheating. Yes, the tanks are a different safety issue. But these pumps are worth restoring. With a refurbished valve plate and routine oil changes, this pump could run for decades more.


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## stevon (Mar 5, 2019)

68Futura,

I meant new pupms like this nice separate cylinder unit :









3HP 2-Piston Twin Cylinder V-Style Replacement Air Compressor Head Pump 1-Stage | eBay


Oil sight glass for easy maintenance. Twin Cylinder Air Compressor Pump. Required Oil: Air Compressor Lubricating Oil. Pump Drive: Belt Drive. With the high exhaust efficiency, low noise, smooth operation and less fuel consumption, it's the best choice for you.



www.ebay.com





Stephen




68Futura said:


> When you say new cylinders for $100 more or less, do you mean a new pump?
> 
> One reason may be, and I forgot to mention this earlier, these Brunner compressors are very durable and well-built units. Brunner was one of the largest manufacturers of compressors in the world. They introduced this design in the mid 1930's, and many are still running today. This model was even used for refrigeration aboard naval ships during WW2. I have quite a few of them, a 1958 that I use every day. Compared to any modern reciprocating compressor, these compressors are quiet and can run indefinitely without overheating. Yes, the tanks are a different safety issue. But these pumps are worth restoring. With a refurbished valve plate and routine oil changes, this pump could run for decades more.


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## MacMcMacmac (9 mo ago)

You might still be able to get parts from a company called Atmosphair in Toronto.


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