I've a pain in my head now... [Vacuum Hubs]

Are your wheel bearings ok? Knackered ones can affect the seals. Also are the spirits blocked with crud? Vac hubs are greased and clean?

The release action is the one that depends on the wheelbearing outer (inner I suppose as it is the one on the inside nearest the swivel housing) seal to the stub axle.
A small amount of leakage is tolerable, provided the vacuum tank is full (empty :dry: ) so you get maximum vacuum applied to the hubs.

(don't sit there ticking over going 4wd-2wd-4wd-2wd as it takes a few seconds to replace the vacuum in the tank)

Did you check the front wheelbearings for play as j99pre is suggesting?

I suppose sand/mud could wear the seals, but that would soon destroy the bearings too.

@j99pre

Wheel bearings okay. No play when rocking at 12-6 and 3-9 with the wheel on. No noise either (pretty quiet at 70mph considering).
Spouts/Spigots are okay I think; I gotten an air line at them and there is flow
Vac Hubs are greased. Not sure with what, looks like bog standard lithium grease.

Now, from what I can understand there is no seal on the hub side of the outer wheel bearing? I can see the bearings through the grease when I pop the vac hub off.

Correct, there is no seal on the outside, as the vacuum passage to release is through the roller bearing :ohmy:
Vacuum passage to engage is between the CV stub and the inner bore of the hollow stub axle.

With the black outer hub removed, there is a seal on the black hub that runs on the polished surface of the extended lip/shell of the hub nut (needs a peg spanner to undo)
Release vacuum goes outside the shell through small holes in the black hub, engage vacuum goes inside the shell.

The extended shell is one reason why you can't just bolt SJ hubs on, so we fit spacers to move the hub outwards.
Don't grind the shell down to fit the SJ hubs, as new nuts are hand made from pure unobtanium, and are stupidly expensive, and the hubs still jam because the jimny CV has a circlip and thrust washer that the SJ doesn't.

I take it you have a pdf manual? They are easy enough to find online, I think there are links posted on here.





If you do go for manual hubs, make sure that you get all the conical washers from the bolts, these are also made from unobtanium


EDIT: if the black hubs are not tightly sealed to the rotating hub, they will leak vacuum and never release, but will engage as the rubber seal is internal around the lip/shell.

facade wrote: The connector just releases somehow and pulls off. It is obvious after you cut it off what you should have done :pinch: .

I spent about half an hour trying to disconnect the oxygen sensor on the RAV4. Couldn't do it, squeezed/pressed/pulled, stuck screwdrivers down the sides etc.

Cut the wire and lifted it up where I could see it, got both hands to it, and it just slid apart :ohmy:

I don't understand why the connector is made like this. A simple plug would have done. I took ages getting mine off but when I found the right knack it was not too bad.

Nice explanation facade.

So glad I fitted manual hubs.

Final piece of the puzzle.

Vac Hub gasket isn't in great shape (honestly, why did I not check this sooner). Going to try to bodge one up out of some thin sheet rubber just for the fun of it tomorrow.

Soap bubbles helped confirm this.

If that doesn't work I'll get some shiny gaskets of the t'internet or off Suzuki.