Looking at a 96 12V down south.
Looking at the dash, I saw a gauge.
The owner didn't know what it was so I made him look more closely at it. He checked it out and it appears to be a vacumn gauge.
At idle, the gauge reads 25PSI.

WHY would you need one? Just to measure how much the vacumn pump makes?

He said one of the indicators said "better economy" etc..

I'm baffled. Anyone have an idea?

 

Sounds like some idiot put one on to measure his fuel economy like you would a gas

Only one way to find out...except the guy probably couldn't tell you where it's hooked into!

Chris

 

prolly not 25psi ......vacuum should be measured in inches of mercury, in Hg, 25 in Hg sounds like what a normal vacuum should be through the pump..... but i dono can you get him to send you a pic?

 

Yes, it says HG, just asked.

It is T'd into the vacumn lines. Double-U Tee F?

 

I've seen people install vacuum gauges when using vacuum over hydraulic trailer brakes.

 

hmmmmmm how far down south are you talking?

 

He is correct. If you've ever driven a truck with vaccum over hydraulic brakes, you'll know if you have a leak this way. Does it also have a red light. To my knowlege, by law, it has to have an alarm with both a visual and audiable alarm in case the vaccum drops to a very low value.

Also see if there is a pull handle under the dash somewhere. This would be the lever to manaully actuate the trailer brakes.

 

yup, ive got a vacuum guage in my truck for my vacuum over hydraulic brakes. Infidel nailed it.

 

The '96 was the last of the vacuum-boosted brake systems - be handy to know the health of the aging vac pump when towing\hauling and on trips.

As mentioned, sounds like a gasser fuel economy gage, which may be what was available to the PO

 

The proper way of typing that in a family friendly forum is: Whiskey Tango Foxtrot. Kind of like that song on the new Bloodhound Gang's album.

Looking for a backup truck?

 

Tow truck for next years pulling season