Vacuum Switch and Filters

Looks like the switch has gone so it stays at max impedace even with vacuum so flashing 4wd light.

The mice have eaten both little filters.

Switch £80 and filters £10 each.

Can you make filters from foam off a sponge.

Getting at the vacuum switch on a 07 is virtually impossible.


Reading Kirkynuts sticky is tempting!

Just fit a switch, its a piece of p*** to do, I fitted a metal toggle for about £3.

I thought flashing 4wd light meant it does not sense enough vacuum, so that should point to a leaky vacuum system?

Not a piece of piss to do at all. It took ages to get it off. I could then get at the electrical connections which I thought I had got to but it seems not and it did switch to making a circuit at 15kPa bit a below half the 40kPa number in the workshop manual, that's not the problem.

The vacuum reservoir is holding its pressure. Will test the solenoid / vacuum valves for leakage next.

I can find no leaking flexi tubes.

The across the axle metal tubes were new in the summer so will check again but they should be fine

There are three filters one on the vacuum switch and one on each of the two solenoids/ vacuum valves.

They are relitivly small and not made of much. One is not eaten by the mice.

auchenblae wrote: Can you make filters from foam off a sponge.

I should think so, as I understand it the filters are there to damp out pulses in the vacuum, if you can find some similar foam then it should work OK.

There should only be 2 filters, one on each solenoid valve.

They are to stop water, dirt and dead things getting into the vacuum lines, so anything that lets air through will do.

(When you apply vacuum to one side of the hub, air goes into the other side, to push it over, through one of the filters.)

The third filtery thing is likely the non return valve in the line from the manifold to the vacuum tank.