Sourcing the vacuum leak

Any way to plug off/isolate a few sections and narrow the search?
Cheers Steve

Hi Steve, I could not draw this circuit on paper if my life depended on it. There are pipes and hoses everywhere around the tanks and boosters and all of various sizes, but I do get your idea and it is very good. Will have to sit and stare at it for a while to see what the next move is.
Thanks for the suggestion.

A little bit of hose in the ear works wonders for finding vacuum leaks

As Steve has said, block off some of the vacuum doohickies

I would start with the hoses into the power boosters

Just pull them off and shove a good size bolt in the hose, you can test this for leaking with a bit of pressure if you like, Im not a betting man at all but if I was I would put some money on them been crook

The other thing I have had on a Isuzu is the exhaust brake diaphragm, same result every time you have no accelerator and the switch is on

Paul

Thanks Mrs, I did forget all about my piece of garden hose hanging up on the wall just for such an ocassion. I took a phone call today with an offer of a proper mechanics stethoscope. This should help me hear as both lug holes will be plugged when testing. I will knock up some round blocks of wood as some of the hoses are 20mm bore or bigger so that will block them as needed. This will be an exercise to be done once we come back from our little weeks holiday away in our van from this weekend.
I'm having so much trouble regulating Dee's governor she is over revving so much and I'm not that far behind her but keep it well hidden until we are on the road.