im doin the valve seals soon and i heard it is useful to hit the retainer on top with a socket to break the keepers loose. i also heard that you can remove the keepers by giving the socket a good whack. what i want to know is should i tap them before or after the cylinder is compressed. i dont feel comfortable doing it before because i dont want to drop a valve. will it be just as effective to tap it when the cylinder is compressed or what. Also does it matter if my engine is at tdc or can i just stick the compressor adaptor in each hole without worring about piston location.
Thanks

 

i use a piece of pipe with a cap screwed on it as my special tool, but only with the heads off the engine, not sure if i'd do it with air holding the valve in place. using the special tool you can strip a set of heads in a few minutes, fast and easy

 

thanks but i need to know with the heads on what to do i dont want to drop a valve, but i do want to loosen keepers so they come out easy...