Glad you found the leak. I had a similar problem on a VW with vacuum locks where the vacuum pump would run for 2 minutes before timing out. All locks worked normal and there was no vacuum leak. Took pump apart and found bad solder joint on printed circuit board at switch relay. Re-soldred joint and fixed problem. Just thought I'd mention it in case someone gets a problem similar. Thanks for telling us the solution to your problem. We all learn a little more when someone fixes something.