On the CP-797, do you put oil in the hammer case?, there is a small plug up front.

C.P. recommends 3/4 oz. of SAE30 oil in the hammer (clutch) mechanism, and SAE10 for the air motor.

YOU WILL NEED TO DISASSEMBLE THE TOOL.
START BY REMOVING THE HAMMER CASE AND INSPECT THE ANVIL AND HAMMERS FOR DAMAGE, AFTER TRY AND TURN THE ROTOR SHAFT IF LOCKED YOU WILL NEED TO DISASSEMBLE THE AIR MOTOR AND INSPECT THE PARTS FOR WEAR OR DAMAGE.
FOLLOW THIS LINK TO VIEW THE PARTS SCHEMATIC.
http://etools.cp.com/cpvscatalogue/files/CA155616.pdf

It takes 70 cc of oil in the gear casing. Too much oil will snap the connecting rod. If it did not have oil in it there might be a leak somewhere

air tool oil, its a special oil, you can use marvel mystery oil also, but would go to auto parts store and get air tool oil

This is from the CP734H manual.
Check clutch oil once each month. Use 3/4 oz.
(22ml) of SAE#30 oil or equivalent.
Make sure the oil is non-detergent.

Get 4 quarts of JASO MA certified motor oil. I recommend synthetic , it will shift better when hot. Amsoil is a good choice. Place an oil pan under the front of the motor. Use a 6 point socket to loosen the bolt on the round finned oil filter cover on the front right corner of the motor and spin it off.Take the oil filter out of the cover and make sure you save the washer that will stick to the rubber seal. Pull bolt out of cover and replace o-ring. put bolt back thru cover, first slide on spring,then washer,and then filter and spin back onto motor pressing filter against engine case. Snug bolt but do not over tighten. Now remove bolt in the middle of the front/bottom of motor(large one in middle , NOT small one under water pump). Check aluminum washer,if bad replace.After oil has drained put bolt back in , do not over tighten.Take off fill plug on right rear corner of motor(by final drive shaft) Using a funnel pour in 4 quarts oil (3.9 is correct amount, 1/10th quart does not seem to bother anything). Put plug back in , start up, and check for leaks.

The oil seal on the sprocket shaft has probably gone bad. Remove the sprocket then clean the shaft to aid in removing the old seal. A screw driver and small hammer is used to pry the outer edge of the seal inward. Realize that you will butcher the old seal in the process of removal. The only other way to remove the old seal is to pull the engine and split the center case.

Stripping it? Do you mean your rounding the head of the plug? If that is the case, you'll need to use vise-grips or channel loc pliers to remove it.

Take a hammer and pound the plug as if you were pounding it into the drain hole, that will help to loosen the crud that is prevent its removal. Use good judgment when hammering the plug, don't cave in the oil pan.

Once you get it out, buy a new plug to put back in

Get a new seal before taking the sprocket off. Remove the sprocket cover plate. You will see two small bolts holding a lock plate on the sprocket. Remove the bolts, lock plate and sprocket. Clean the sprocket shaft so the new seal is not damaged when installing. Now just pry out the old seal any way you can with a screwdriver and small hammer. Install the new seal flush with the casing.

in a 4 cylinder diesel 2x cp 70 in front cp71 in the rear the reason why inline fuse blew cause by an electrical fault in the alternator thanks heaps after the alternator was replaced it work