I picked up a new vacuum gauge from HF about 8 months ago. Never had the need to use it. I recently rebuilt the carb in my 58 Burb so I decided to see what the vacuum was like.

The gauge seems to work ok. It registered a pretty steady 18 inches of vacuum. My problem is that the gauge doesn't go down to 0. Right out of the box it says 10 inches. The vacuum reading was actually just below the peg past 28 inches. I subtracted the 10 to get the 18 reading.

There doesn't seem to be any adjustment. Does anyone know if there is a way to 0 the gauge. I thought it might work like a compression gauge where you have to release the pressure between cylinders. There isn't anything in the very limited instructions that came with it. I'm confused!

Thanks

Larry