Replacing air hub pipes with silicone hose.

I was lucky, ooky_123 kindly gave me a set he removed from his car.

What happened with mine was the engage valve leaked when off, the spring inside must have gone weak. This stopped any vacuum building in the tank.
When I put it into 4wd, the engage solenoid operated, and the engine could build a vacuum and suck the hubs on, but it took 2 or 3 seconds to do so.
Going to 2wd, the leaky engage valve prevented any vacuum forming and they wouldn't come off.

I removed the panel with them on, squirted mighty GT85 (the mechanics best friend) into the pipes of the engage solenoid, and operated it from a battery about 100 times. This has freed it off and it is working now, but likely to seize again any minute I suppose.....

From memory, both valves take vacuum at the side port, and keep this sealed when off. There is a path straight through from top to bottom when off, (a filter goes to the bottom) this lets air INTO the hub so the hub is free to move. When you engage or disengage, the required solenoid connects the vacuum port to the top port, applies a vacuum to one side of the hub, and the air going into the other pipe pushes the hub over with a nice clack.

What ages / models have vacuum operated freewheeling hubs fitted?

Si

On all UK spec jimnys(1998 on)

One working solenoid.
[ I think ]
The air path changes when attached to a battery. Will refit it to the car soon.
Hopefully the familiar clonk, clonk, click, click of the 4wd will return.
Thanks to all.

Az1987 wrote: On all UK spec jimnys(1998 on)

Not on mine! It's a 1999 Soft Top.

Si

All fixed and working fine.
What a difference fixing the solenoids has made, the hubs are very quick to engage and disengage.
Let it snow, let it snow, let it snow.:laugh: