One diagnostic tool I've been using a lot lately is a borescope that can be inserted into cylinders, radiators, transmission housings, etc. Mine plugs into a USB port on my laptop and gives a full screen picture of whatever I'm looking at, and it has a variable-intensity LED light built in. It fits through a 5MM hole and has a 36" probe with a 6 foot USB cable attached. Mine cost $48.00 on E Bay, with free shipping!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!