Originally posted by Big Jim:
About an 1/8" hole would probably not hurt the operation of the thermostat and some are built that way, but I have an alternative suggestion.
This is a trick another technician taught me years ago to help fill the cooling system more easily. With you fingers, gently force the thermostat slightly open. Insert a plastic spray wand from an areosol can (such as one left over from an expired can of WD40 or choke spray) into the thermostat opening forcing the thermastat to not fully close. Clip off the wand so that it doesn't interfer with installing the thermostat (about an inch long piece will usually do).
This keeps the thermostat from fully closing while you make the initial fill. Once the coolant warms up enough for the thermostat to open, the small piece of plastic wand floats away into the coooling system where it will do no harm.
Since learning this trick, I have seldom had trouble getting all the air out of a cooling system.
A similar and probably even less intrusive than a piece of plastic would be to use an asprin or two. They just dissolve in coolant when the fluid reaches them.
However, as you said, one or two small holes probably wouldn't hurt either.
TB
"Seems like our society is more interested in turning each successive generation into cookie-cutter wankers than anything else." -- Jato 8/24/2004
| 
