Posted by chriscase on Thursday, August 31, 2006 at 8:56PM :
In Reply to: Temp gauge posted by Robert N. on Thursday, August 31, 2006 at 11:21AM :
Careful when heating those parts, they are soldered together. The bulb on the end is full of ether, that expends when heated, making the pressure gauge on the other end read higher. To remove the bulb, first remove the small freeze plug in the top of the head, just above the bulb. Then you can push the bulb out with a "pry bar" (expendible screwdriver).
But, if yours is stuck on high, I'd start at the dash end. Pull the cluster, disassemble the gauge from it, and inspect for wasp nest or other debris blocking the needle/gauge movement.
The whole ssystem can be "rebuilt" by adding a new bulb from a $20 gauge. Just put the new bulb in salted ice water, to 'freeze' the ether, then cut the capillary tube on the new one, and solder it to the old capillary near the gauge, so it don't show under the hood. I used one of the red crimp connectors with the red plastic peeled off as a splice- it was already tinned. Once it is sealed together, without plugging it with solder, put the end in boiling water to calibrate- bend the gismo that makes the needle move. I used needle nose and a pair of "inside out" snap ring pliers that spead things apart. Fiddle with it to get it to read 212 in boiling water, and 140 in hot tap water.
CAREFUL! I did heat some water in the microwave that was plenty hot, but didn't boil- until I inserted the bulb, then it exploded into boiling steam! I guess it does take some kind of point for the steam to form on. Must have been the cleanest coffee mug I ever washed...
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