You may need to remove the guage from the console. If the front and back halves of the console do not come apart, you will need to remove the hose from the 1st stage, remove the compass, and push the gauge through the circular opening where the face of it sits. A hot water soak will help soften the plastic/rubber a bit to aid the procedure.
Once out of the console, you can use a couple of wrenches to separate the hose from the gauge. One wrench to stabilize the gauge and the other to turn the fitting on the end of the hose.
Between the hose and the gauge is a part called a "high pressure spool" it is a small metal piece that has a tiny o-ring on each end that seals the hose-gauge junction while allowing the gauge to swivel around. The o-rings wear out and typically cause bubbling at the hose-gauge junction.
Spools are relatively inexpensive ($1-$5 depending on where you buy them), but there are a few things to watch out for....the spool will most likely stick in either the gauge or the hose end, just grab it gently with a needle nose plier and pull it out. There are generally 3 different types of spools and they are generally not interchangeable, be sure to purchase the correct one. Most spools use size 003/90 shore o-rings....the o-rings can be replaced but it can be a pain in the arse to remove and replace them. There is a tool that facilitates the installation of the o-rings but it is not really worth the money for the one or two times in one's life that they will perform this maintenance. Some will say it is not worth the time and effort to replace the spool o-rings, but it is possible to do if you can't obtain a replacement. Use some silicone or O2 friendly grease on the spool ends before reinstalling/reattaching the hose.
-Z
