The Mitsubishi Pajero Owners Club®

[hedne]

Hi, i have problem disengaging my car from 4WD to 2WD. Today I checked the vacuum pipes but i am not sure how to understand the result...Any help would be welcomed.

When in 2WD and I take lose any of the blue or yellow pipe from the actuator I can hear a distinct sucking noise, like they are working well and doing their job.

When in 4WD I can hear a distinct sucking noise when removing the blue pipe, but nothing when removing the yellow. It seems like this is in order, that this is how the actuator should work?

THEN there is another third vacuum pipe that goes all the way to the axle. When pulling this there is no distinct sound either in 4WD or in 2WD. Could this be the culprit? What does this 3rd pipe do without any vacuum in it?

[Google]

[hutchy]

pull back the rubber boot on the actuator and see if it will move by hand it may just need a good lube up

[Mark3]

There should be vacuum at one or the other but not both at same time!

Your problem is most likely down the twin VSV' s on the drivers side inner wing behind air filter.

There job is to supply vacuum to one side or the other of the diaphragm housing to engage or disengage front diff, the non vac side should be open to atmosphere and when they fail you get vacuum at both sides at same time so it either won't disengage.

There cheap cheap cheap from a breakers and easy to fit  

[hedne]

folks, I think I have come close to the solution. When I switched the blue and yellow pipe the actuator went alive, though not fully. When I compared the vacuum strength between the yellow and blue solenoid I noticed that the yellow pipe was much weaker than the blue. Tracking the pipes I found the yellow pipe goes down to a sort of metallic can. This can doesn’t seem to produce vacuum any more, as I would suspect it should do? The blue pipe goes away to the motor somewhere and produces a lot of vacuum. The pipes are actually intersected but it distributes more to the blue because it is straighter I think. The yellow pipe actually drain vacuum then because the can isn’t working.

Could this be the problem, is the can supposed to produce vacuum?
Very thankful for any ideas before I buy a new one...

[hedne]

Well, I think maybe I was a little bit hasty, the can is probably for storing vacuum and not creating. After thinking it through, it does seem like the blue solenoid is the problem. It doesnt shut when in 2H, then it probably takes vacuum from the yellow pipe too and it gets too weak.
i will order new solenoids and see if it works.

[trekker]

Yes, I'd say you're on the right track there.

In time, that tank also need a clean and paint to avoid pin holes developing.

[hedne]

For update, I think the problem is almost solved. I switched the source vacuum pipes between yellow and blue to get the stronger vacuum current into yellow, then blocked the blue solenoid with a plug. Now it goes into 2WD without any complains, and the green light stops flashing too. So the problem must be the blue solenoid or the cable leading to it. This is good enough for me anyway, I will keep it like this until I get hold of new solenoids.



Thanks alot for every help I have received here!

[hutchy]

deffo sounds like you got it...i always keep a spare set in the shed just in case...as they are expensive from the dealer

[KEVINBUK]

Is the "third pipe" you mention in your first post the diff breather ? How/where does it end at the opposite end to the axle ?

K  

[hedne]

[RogC]

Have a look here
I did some fault finding on the solenoids this explains how they work

Super select Solenoid fault finding