I just purchased my 1st Skid Steer (CASE 1530). During the initial inspection I noted three gauges along the right side of the cab, an Amp Gauge, Hour Meter & a gauge labled Vacuum. I asked the owner about the vacuum gauge and he said he really did not know the specific function. He said that the gauge was not functioning when he bought the skid steer and, because it did not seem to impair the unit's operation he never saw fit to get it repaired. Since I'm still on the hunt for manuals for my 1530 I was wondering if someone it the forum might be able to tell me what the purpose is for the vacuum gauge.