I am assuming you mean the ram. That is usually air leakage around the leather seal ring and the inner cast iron rings. If you mean the piston, then you probably have a problem with the crank shaft.

I am assuming you mean the ram. That is usually air leakage around the leather seal ring and the inner cast iron rings. If you mean the piston, then you probably have a problem with the crank shaft.

 

yes i'm talking about the ram. (sorry for my english) :-) but where are we talking when you say leather seal ring? and where are we talking when you say the inner cast iron rings? it is inside, and above the cylinder?

and what does this require to change?  thank you so far. 

Part No. 53 in this diagram is a leather packing ring, if that doesn't seal right the ram will not draw up into the housing. Also on the bottom of part 55, which is the inner ram guide there are cast iron piston type rings. And on the top of the ram where there is the flange there are cast iron rings. I was told when the hammers were new they did not have the cast iron rings, they were added later as the ram wore in the housing and caused air leakage. When I got my hammer it did not draw up as it should, was a combination of poorly fitting cast iron rings, and a leather seal that was shot. I also had to rebuild the valves to prevent air leaking around the valves.
First thing I would try is the simplest, but still a lot of work. Remove the ram cylinder head, part no. 3, remove the ram, and replace the leather seal in the ram guide ring. Inspect for rings, and their fit, they should be no more than ten thousands, which is very sloppy actually.
Replace the parts and see.
One trick, while the ram is removed, use feeler gauges to check the tolerances on the valves, there are horizontal slots where the air comes from the piston to the ram. The valves are where it is at in my opinion. My hammer did not run right until I got them within one thousandth. I sent the valve sleeves, which are removable out to be professionally cylintricly ground. Then I blazed up the valves with bronze rods and precision turn, and lap in place. Through ABANA Bob Bergman has a great video on rebuilding these hammers and a great packet of information as well. Well worth the money IMO.
Hope these pics help.

Here is some more good information from an old Nazel catalog I have. You can find me Matt Harris, on Facebook where I posted the entire catalog in my pictures.

Here is some more good information from an old Nazel catalog I have. You can find me Matt Harris, on Facebook where I posted the entire catalog in my pictures.

thank you so much it's really useful information... :-)