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Super Select vacuum hose replacement

Posted: Mon Feb 06, 2012 4:32 pm
by pierreandre
I had all the 4x4 switches replaced 2 weeks ago and this solved half the Super Select problems. All selections (2H, 4H etc) now works perfectly when the vehicle is cold.

The main problem still remains: After driving for a while in 2H, either the orange light starts flashing, or 4H selection doesn't work. When driving in 4H, the front green lights start flashing, which normally also leads to the orange doing its thing.

Mitsu did find one leak on the vacuum hose and fixed it by cutting the hose shorter. The theory was that the hole was very small and only started leaking as the hose heated up.

The problem is better, but still there. My feeling is that if one hose had a leak, there may be more. Should I replace them, and with what? Or is the problem with the solenoids?

Re: Super Select vacuum hose replacement

Posted: Mon Feb 06, 2012 6:42 pm
by 4ePikanini
sounds to me the vacuum pipes are incorrectly configured. get a friend with a pajero to compare pipes ;)

Re: Super Select vacuum hose replacement

Posted: Tue Feb 07, 2012 7:33 am
by pierreandre
I doubt they are incorrectly configured. Everything works perfectly when cold. Its only after continuesly driving for 20-50km that the problems start.

Before Mitsu fixed the leak they found, it wouldn't go into 4H when hot. Now, it won't go out. I know the actuator has two pipes, one to open and one to close. Perhaps there is a leak in the other one as well. I don't have a vacuum pump to test it, so that's why I thought it would be easier to just replace it all.

Re: Super Select vacuum hose replacement

Posted: Tue Feb 07, 2012 8:42 am
by 4ePikanini
Mine was incorrectly configured. One of the hoses was swapped with the diff breather.

The ecu only kicks in the orange center diff orange light after 5km-50km.

It may or may not be your issue but you definitely have a vacuum issue. It could be that the hoses are too old and they collapse when warm allowing the vacuum to keep it collapsed while the vacuum diaphragm slowly loses the vacuum on its side and releases the actuator rod.

Re: Super Select vacuum hose replacement

Posted: Tue Feb 07, 2012 11:25 am
by pierreandre
Scary stuff.

I agree, everything points to faulty pipes. I'll check the configuration, but I have a feeling that replacement is needed.

I'll see if I can get a set out of Mitsu.

Re: Super Select vacuum hose replacement

Posted: Tue Feb 07, 2012 11:37 am
by 4ePikanini
no need to get them from mitsubishi. Just get a few meters from your local hose store and cut to length.

Re: Super Select vacuum hose replacement

Posted: Sun Feb 12, 2012 5:59 pm
by Zabwan
Hello.
I did have a similar intermittent problem with the super select system.

It turned out to be the solenoid coil breaking down and its resistance value changing as the vehicle warmed up.
After about 5km of driving, the front diff would start trying to engage, making a slight grating sound.
As the 4by system is a fail safe system ie it will always fail into 4by mode, the slowly degrading resistance in the solenoid coil allowed the vacuum to slowly escape, and so produced the problem.

A simple multimeter on the disconnected coils to check if the resistance is in the range of 36-40 ohms @ 20degrees celcius
per coil will eliminate this possibility

Re: Super Select vacuum hose replacement

Posted: Mon Feb 13, 2012 7:24 am
by pierreandre
@Zabwan: Thanks, this sounds like a real possibility. I will definately try that. I've checked all the hoses, and I don't think there are any leaks. The only thing left is the solenoid.