The International Cessna^® 170 Association

Have a friend with oil leaks at the upper pushrod tube housings on orginal O-300 . What is the tool number to re crimp them ? Can it be used with the cylinder installed. Any advise would be apreciated.

The tool (Burroughs 4915A) and less expensive copies(about $35 I think is what I paid for mine) are sold by El Reno 800-521-0333 (and others) and the repair can be done in situ. All you must do is remove the rocker covers, rocker arms, and pull out the pushrods. (Do this carefully so as not to extract the tappets in case you have the old style. This may be done by rotating (twirling) the pushrod until it releases from the socket of the tappet. Another method is to apply low-pressure air to the upper end of the pushrod, injecting air thru the hollow pushrod to "break" the oil-suction at the tappet.)
Keep the pushrods in order, so they can be reinstalled exactly in the same location as they came out.

Don't get carried away with the tool. It only takes a little bit to fix the leak. (Similar to torqueing a bolt...just because a little torque is good...doesn't make a lot of torque better.) You don't want to overdo it.

Don't know the tool number. Yes it can be used by removing the push rod. Be careful not to pull the lifter out of place when removing push rod. Might want to plan on doing them all. unless you are sure this is the only one.

As for the tappet (lifter body) issue, see:
http://cessna170.org/phpBB2/viewtopic.php?t=3027

Thanks to all for the info. I will pass it along.

There may be an issue with the center cylinders (nos 3&4) removing their rocker arm shafts. Sometimes the cylinder base nuts must be loosened to get enough clearance to slide the shaft out past the adjacent cylinders.