Pneumatic Squeezer Maintenance
It's not often that we post, but there are times when facts can be posted for the benefit of all.
Pneumatic rivet squeezers have been around for 60-70 years, if not more. During that time manufacturers have tried many different things to "tweak" the tool. In the CP drawings, for example, they're showing O rings instead of leather pistons. APT also tried using O rings on some of their tools. However, for the most part the tools remain basically unchanged after all these years.
On older Chicago Pneumatic squeezers, there was an oil hole in the lever shaft, still shown on part #79 on the CP drawings, (the cam shaft). It is located directly below throttle lever arm on the side of the tool. Chicago Pneumatic was the only manufacturer whose tools had this feature. The purpose of this oiling port was not to lubricate the bearings, but to lubricate the cam as it rotated around the lever shaft. All other manufacturers had a solid lever shaft. At some point in time Chicago Pneumatic also changed to a solid lever shaft, but their drawings are still showing otherwise.
Most pneumatic squeezers have a very heavy solid leather piston. The reason DGlaeser could not see the entire piston is because there is plate that goes over the interior portion of the piston, so if you're looking down the cylinder all you can see is the outer edges. This heavy leather piston rubs directly against the aluminum walls of the air cylinder.
Over the years there have been many advancements in the petroleum industry. At present, there are two types of grease used in pneumatic squeezers. The first is a very heavy, highly water resistant grease used on the leather piston in the air cylinder. The second is a special bearing grease used on the roller bearings and the cam bearings. There are normally 72 bearings in these tools. However, one fact that has NOT changed with respect to the petroleum industry: light oil will, in fact, wash away heavy oil, oil will flush out grease, and water flushes out everything. As time and parts are expensive, one of the favorite tricks we have seen is for a seller to generously lubricate the air cylinder of a squeezer with oil to loosen up hardened grease and sell it in "good operating condition". It works - for a while.
CP is the only manufacturer we know of that recommends oiling the air cylinder. In their drawings and instructions, this is explained by the fact that they are using O rings instead of leather pistons. However, we will unequivocally state that we have seen very, very few pneumatic squeezers of any type that use the O rings instead of the leather pistons, even from CP. In fact, every single manufacturer we are aware of is currently using a leather piston in their tool.
We have often seen pneumatic squeezers come in for repair/rebuild whose front ends are literally packed with grease. That extra grease does nothing but clog the tool and hold aluminum chips. On a pneumatic squeezer, the base and sides of the set holder should be lightly greased where it passes through the yoke and contacts the cam. The front of the cam where it contacts the set holder should be lightly greased. Maybe once a year, if you want to be extremely thorough, you can take off the bearing cover plate on top of the tool and lightly lubricate the roller bearings that contact the wedge. Any good bearing type of grease or Lubriplate will work. This is all that is required.
For the record, ourselves, Avery, Cleaveland, and now planetools, all get our new pneumatic squeezers from the same manufacturer. We, in turn, manufacture the C-Rex yokes and accessories. The manufacturer of the squeezers specifically state in their instructions and warranty NOT to oil the tools. Therefore, for a seller to suggest otherwise is a direct contradiction to the manufacturer's directions. That's all I really care to say regarding that matter.
Seems that I have elaborated at nauseum. Hopefully, though, this will clarify matters and help builders better understand these tools. Please, though, let's not go into the 2x vs 3x vs 4x arena.
Blue Skies!
Fred W. Kunkel
CLEAR AIR TOOLS
www.clearairtools.com
. All the mechanism that would need lube is on the non-air side of the piston. When you take off the yoke, and the set holder (fixed or adjustable) falls out, you can see the mechanism if you look in the hole (not much to see really) and squirt some grease in there if you want. The piston drives a wedge between a fixed roller and one attached to a cam which drives the set holder. There are springs in there to push the piston back. Very simple. Any oil in the air hole would go no farther than the piston, and apparently it isn't good for the leather seal.
