I run a VAC gauge in my 4Runner.
Its wired into the dash.

Every oh 5-10 years or some 100K miles, the meter seems to give up the ghost and the meter will no longer read "full range". It seems to get stuck and only move in 1/4 of the dial and not the full dial.

Am I just wearing them out? Is this "normal" as a mech gauge simply "metal fatigues" the spring?

These are Autometer Sport Comp gauges.
Tho #3 replacement is the liquid filled pro comp one.
The fluid should dampen out the occasional fluttering I get.



Being Hauled out of storage
Interior reeked of mouse piss and mold
Hence the bag over the stick shift - the knob plastic was all sticky...

 

Here is another pic of Gauge #2

It now will only read between 15 and 0 - even on full deceleration with the throttle closed

 

I would venture at @ 100,000 miles and that time frame just plain wearing them out

 

Maybe not.

I use the "plastic" tubing to connect it to the manifold.
BUT - the plastic - running across the dash, in the sun, deteriorates in the UV exposure.
So it dries out and "cracks".

I think I get a small piece of something in there that "stops up" the gauge.

I dug out the #1 gauge, and checked it with a hand pump vac meter. It worked fine.
A few more checks and - thats strange - the hand pump gauge is now acting wonky.

After banging it around a bit, it then clears up and works.

So I may swap back #1 into the dash (dated 1990 btw)

And since I didn't open the new #3, I can return that for a "boost" gauge (for the Subaru - which in fact, does have a turbo).

And Summut Racing has free returns - oh YEAH