Suck Gauge -- Vacuum?

[dresslered]

For several years I have been running 5 gauges with the fifth being a vacuum gauge. This was added due to the various vacuum accessories (E-brake, 2-LO, as well as all the HVAC controls) and the ease at which it is to knock a line loose inadvertantly. For years the gauge has always sat at around 26-28 in-Hg. However, over this past week, I have noticed a several inch drop (24-25) in vacuum and a longer temporary drop (10 in-Hg) in vacuum during E-Brake engagement than normal. Everything appears to be working properly, but with the gauge I am able to notice this subtle change. Obviosly, I need to check out all my connections (including the gauge itself), but do the vacuum pumps wear out themselves? Any other ideas? The truck just turned the clock at 100k miles. TIA



David

 

[nickleinonen]

but do the vacuum pumps wear out themselves?

they can... if the checks [might be a reed valve] don't seal well, you can get poor performance