1983 300sd with hard brakes among other probs. I've fixed cooling and charging systems and now on to the vacuum sys. I pulled the line off coming out of the vacuum pump, started eng, plugged in vac gauge and I get 0 inches of vac. Rev it up and I get 0. Before I order a kit for it, I want to know how to check the check valve coming out of the pump and are there any tricks to rebuild a pump? Thanx

 

Found another vacuum pump at Pull-a-Part for $20.It pulls 22 inches..HA!!