4wd light flashing on dash

hi, the 4wd light on the dash is flashing on my wifes jimny so trying to sort it out with out taking it to a garage, i have done a bit or trawling on google and these forums about the problem and all say its the vacuum system failing.

so it was in getting the clutch replaced and i asked the mechanic to have a check while he was under, he cant see any visible leaks in the pipe work but said there wasnt even any suction out of the control box.

so is it worth checking any thing else before i start ordering parts? i know there was a detailed bit on this forums about the vacuum system and to check the little filter on the system if doing them doesnt fix it am guessing i will need spares.

I also got a garage to check the hubs and they weren't engaging either even when rigged up to a vacuum system so is it posible to just take them off and soak them in oil try free them up and put them back on or again is it better getting replacements, she wasn't intrested in the manual lock hubs so would need to be auto 1's again

sorry for babbling on but i dont really know alot about these jeeps and trying to get it sorted incase there is a bad winter this year and the wife wants the 4wd working as we moved out to the country last month. Aslo trying to keep it as cheap as possible so is ther any opinions on getting stuff from ebay? the shop was Cam Suzuki he had alot of stuff in and tihnk he offers a warranty on parts bought

cheers guys any input welcome and will try keep you posted if i get it fixed

what year and engine do you have

if it a single cam engine like mine there is a vacuum pipe coming of the inlet manifold down by the fues box near the battery check that for splits then follow the pipe work down to the valves and have a look at them pipes

the hubs shouldnt be stuck its normaly the vacuum system that givs the problem

its the 1.3 petrol 03 plate. i shall check the hubs non the less its just 6 torx bolts i guess they just pop off after that

yes thats right
is say its more if an air leak/split pipe some where

lets hope so

will the splits be seen quite easily? or can u rub like fairy liquid on them to finbd leaks easier?

also to find the leaks would i just turn engine on put in 4wd and might feel them?

project90 wrote: will the splits be seen quite easily?

Yes in the rubber, especially if you flex it

project90 wrote: or can u rub like fairy liquid on them to find leaks easier?

No it is a vacuum system so no bubbles will blow + see below

project90 wrote: also to find the leaks would i just turn engine on put in 4wd and might feel them?

No, the system only applies vacuum for a few seconds not all the time.

Most likely place for total failure is the pipe from the manifold to the valves, as markyp2000 says.

You could disconnect the pipe at the manifold and plug the engine end, then remove and manually lock the hubs and replace them carefully and it will work, but this is really only a temporary measure.

Get something that will suck a vacuum about 50ml worth- I have a 100ml syringe.
Whip a wheel off and you will see 2 pipes to the hub, disconnect them and apply your vacuum to the spigots you should hear the hub click into place as you suck on each spigot in turn (it only works once in each direction, keep swapping over.)

If that works you can try the same procedure at the rubber pipes where they come out of the valve block.


Mine had a leaky "unlock"valve. This prevented any vacuum forming in the "lock" circuit.