Fuso Canter Transfer Case vacuum actuation

[SkiFreak]

Can anyone confirm or deny this?

I cannot comment on the FGB71 setup, as I have no personal experience with that model, but on the FG84/FG140 with a 4M50 engine, there is a dedicated vacuum pump at the front of the engine.
As to your second question... there is only one vacuum source, which things like the brake booster and exhaust brake draw from. The brake booster has it's own circuit, as does the exhaust brake.
As you have noted, the actuating solenoid for the exhaust brake can be triggered by different electrical events, like depressing the clutch peddle or accelerator and be enabled/disabled from the exhaust brake stalk.

 

[OzWanderer]

Hi All,

Re: disengagement mechanism

Before I go and start taking the vacuum relays circuit apart and probing around why the disengagement does not work, I wonder if the disengagement is done by a kick-back mechanism in the transfer case which only works if the truck is moving?

The reason I ask first, is because it is not easy to move the truck by anything more than 2 or 3 meters as there are other works going on around it at the moment.

cheers

 

[BigSkyBrad]

It’s vacuum both ways – the actuator sucks one way to push in the transfer engagement shaft (and hold it there), and sucks the other way to draw it back out again (and keep it out). Is yours engaging , but not disengaging ? - which could be the engaging solenoid is working but the disengaging one is kaput.

There may be a natural kickback out of engagement, but that’s just gears who don’t want to be engaged if they can help it! The vacuum keeps the shaft engaged – if there is no or poor vacuum, a grindy noise can be heard as the gears are semi engaged and fighting.

Even on a good day, vacuum systems suck!

 

[SkiFreak]

Even on a good day, vacuum systems suck!

I totally agree.
In my opinion, a positive connection is a much more reliable system.

I can only assume that Fuso went with the simplicity of pressing a button to select 4 wheel drive and low range, opposed to having to include a mechanical changer, which takes up more space in the cab.
I like mechanical connections to things, so I am happy to sacrifice a bit of cab space in order to have this functionality, which my FG84 has.

 

[OzWanderer]

True. Not being a mechanical minded person, don't even know how to start.

 

[Aussie Iron]

I totally agree.
In my opinion, a positive connection is a much more reliable system.

I can only assume that Fuso went with the simplicity of pressing a button to select 4 wheel drive and low range, opposed to having to include a mechanical changer, which takes up more space in the cab.
I like mechanical connections to things, so I am happy to sacrifice a bit of cab space in order to have this functionality, which my FG84 has.

Well that was a step back for Mitsubishi then..

Dan.

Back to what I said in post #8. A real step Backwards.

Dan.

 

[BigSkyBrad]

...and why have a push-button system to use from the comfort of your cab, when you have to get out in the rain and mud to turn the hub locks!

 

[OzWanderer]

Wait until the day everything is done with APPS.... Multiple points of vulnerability.

 

[Aussie Iron]

Wait until the day everything is done with APPS.... Multiple points of vulnerability.

Will never happen on a vehicle I own so no problem to me. And saying that I will be more than happy to drive around you if you are suffering problems caused by computer/APPS usage in a vehicle.

Dan.

 

[OzWanderer]

Will never happen on a vehicle I own so no problem to me. And saying that I will be more than happy to drive around you if you are suffering problems caused by computer/APPS usage in a vehicle.

Dan.

I actually look forward to the day when we have 4 separate electric motors on each wheel, that would be real 4x4, but that may be anathema. No diff, no locks, no transmission, few mechanical parts. Everything electronics, just swapping electronic cards in and out when faulty. And plenty of range...that'll be the day. I heard that Tesla is getting there ?! But their car can't take corrugations, I don't think. Anyway, we sidetracked.

 

[OzWanderer]

Hi,

Been busy for a while trying to sort out the fitting out and "engine sys" problems, but now is the time to update the situation.

The disengagement problem turns out to be just a matter of driving the vehicle for a short distance after pressing the button, then it takes effect.

Now I have also drawn what I can of the complete system diagram, and your comments are welcome, but bearing in mind, I am not a mechanical or fluid engineer !

I think the system works this way, solenoid A and B would flip flop, out of steps, between connecting the vacuum or air to the top and bottom lines of the actuator. What I don't quite understand is, why an air bottle is needed ? Perhaps to filter out the dirts from outside, instead of just letting the lines hanging in the air.

Perhaps I interpret it all wrong.

Here is the diagram.

 

[Aussie Iron]

Your drawing makes sense even though I can't tell you if it is what you have. I will agree that if you followed your vac lines then it is right.
Then that bottle doesn't vent to air. Outlet lines A2 and B2 vent and take in air as they cycle. By making it a closed circuit you don't get any foreign dirt/dust/ water into the valves. The bottle is there to make up any difference in the volume in the valves as they cycle. Each solenoid valve must then also have a spring in them to be able to cycle to the other position (maybe reverse the polarity in the coils to make them shift to the other position "NO" they wouldn't).

If your system is working now then you have it right.

Can you post a picture of 4WD Actuator as in is it one actuator or two as in the earlier models. How many lines does it have running to it/them.
Just interested.

Dan.

 

[OzWanderer]

Here is the photo of the actuator after I have cleaned and lubricated it with Lanotec and Inox. It was rusted and with dirt inside the rubber cover through and through. The actuation arm is actually pitted, to give you an idea of how rusted it was.