Mechanical Oil Pressure Gauge ?

[HDDOC]

Anyone happen to know why motorcycle oil pressure mechanical gauges are filled with fluid. Could one remove the fluid and still have a good reading?  I have one that is old and now has motor oil in it.  Thanks Doc

[Ken R]

Anyone happen to know why motorcycle oil pressure mechanical gauges are filled with fluid. Could one remove the fluid and still have a good reading?  I have one that is old and now has motor oil in it.  Thanks Doc

Doc, I've always wondered about the Glycerine in the gauges, myself.  It is said to be for dampening vibrations. 
About 4 years ago, my HD oil pressure gauge leaked all the juice out.   It still functioned (dry) for three more years without issue.  I replaced it for other reasons. 

Ken

[96dynabagger]

Interesting, my HD gauge leaked all over too (in just a few months).
Replaced it with an Accel unit and its been fine ever since.

The fluid helps to prolong the life of the brass tube inside from pressure pulsations.

[HDDOC]

I just got another one from Warner. works good , will see how long it lasts with no fluid in it.  Thanks Doc  $6.00 could not help it.