exhaust brake problems

T

Turtle59

Intrepid Wanderer
G'day blokes and blokettes

Well after some driving and thinking I came to the conclusion that the exhaust brake isn't working on my truck.

So I look at the manual I purchased, then go look at the truck and find that the manual is nothing like the truck. Bugger!!!

So I look further. The fuse box. Hmmmm no fuse in the exhaust brake spot... so I think an easy fix... insert appropriate fuse, start the engine, and hey presto... the exhaust brake is on all the time and the lever on the steering wheel makes no difference, regardless of where you put it. The light comes on in the instrument cluster and doesn't go off unless I pull the fuse.

What is going on here??? Anyone got any suggestions for me of what to do to fix the problem???

Anyone got a manual for sale? Digital is good or book.
 
K

kerry

Expedition Leader
On mine there's a switch on the dash to turn it on so it can be used to warm up the truck. Hit the accelerator and it goes off. Release the accelerator and it comes back on. Maybe there's a problem with that switch or that circuit.
 
pugslyyy

pugslyyy

Expedition Vehicle Engineer Guy
Hmm, initially I was thinking it was a throttle sensor problem but if the lever on the steering column doesn't turn it off then probably something else going on - that should be a hard off switch for the exhaust brake. This of course assume you don't have the exhaust brake engine heater switch on (which is an excellent way to warm the truck up, btw).
 
K

kerry

Expedition Leader
I've thought more about this. There are two activating systems--the warm up and the 'back off the throttle going down the road' systems. Both of those systems read info from the accelerator pedal to engage/disengage the exhaust brake. So if there's nothing wrong with the pedal position sensor (ie the truck is running fine otherwise), I'd look for the electrical device closest to the exhaust brake as the cause of the problem. I'm not exactly sure how it's activated but for some reason I think that vacuum is involved. I'd suspect that the electrical solenoid which opens to send vacuum to the brake to activate it, probably gets the signal from both systems and is stuck open, always feeding vacuum to the brake.
 
T

Turtle59

Intrepid Wanderer
Thanks for your feedback so far blokes.

Here is what I am thinking... Tell me if I am off the track or in the ball park.

On the accelerator pedal there is a grey circular electronic type gadget with wires coming out of it (whatever it is called). the wires disappear up under the dash... where do they go? There must be a module, controller or whatever they might call it in that line somewhere, then from there in which order does the current travel, fuse, hand lever, preheat switch,?????
I am lost at the moment as to how to advance from here to check where to look next to solve this issue.

Who the hell would know.

I went to see an auto electrician yesterday, he said he has never worked on one of these in his professional life and knows little to nothing of where things are situated on the vehicle and that I would be better off finding someone who has some knowledge with them, or go to Mitsubishi.
 
T

Turtle59

Intrepid Wanderer
kerry said:
I've thought more about this. There are two activating systems--the warm up and the 'back off the throttle going down the road' systems. Both of those systems read info from the accelerator pedal to engage/disengage the exhaust brake. So if there's nothing wrong with the pedal position sensor (ie the truck is running fine otherwise), I'd look for the electrical device closest to the exhaust brake as the cause of the problem. I'm not exactly sure how it's activated but for some reason I think that vacuum is involved. I'd suspect that the electrical solenoid which opens to send vacuum to the brake to activate it, probably gets the signal from both systems and is stuck open, always feeding vacuum to the brake.
Click to expand...


G'day Kerry,

Thanks for taking the time to try to help me out here.


It sounds like you may be on to something there, but where would I find this solenoid so I can test it???
 
K

kerry

Expedition Leader
Go to the exhaust brake, see what activates it. I'm guessing it's a vacuum line which should lead away from there to a solenoid. Check the operation of that solenoid. You may be able to locate that solenoid by having someone install/remove the fuse while you listen for it's movement.
 
T

Turtle59

Intrepid Wanderer
kerry said:
Go to the exhaust brake, see what activates it. I'm guessing it's a vacuum line which should lead away from there to a solenoid. Check the operation of that solenoid. You may be able to locate that solenoid by having someone install/remove the fuse while you listen for it's movement.
Click to expand...

Great suggestions thanks.

I will look into it today.
 
SkiFreak

SkiFreak

Crazy Person
Sorry Turtle, I did not look at your signature....
I have seen electronic manuals for your model on eBay for about $20. That's a real bargain, as getting them from Fuso will probably cost you about $300.
 
blackduck

blackduck

Explorer
Turtle
youll have to excuse Owen he's getting old and his eyes don't work that well anymore :wings:

Ive got the 649 manual tell me what sections you want and pm me with your personal e mail and ill sendl them to you
I would post them here but im not that clever
 
pugslyyy

pugslyyy

Expedition Vehicle Engineer Guy
I like the digital over the paper version anyways. I can research what I want to do on my computer, and if necessary print off a few pages that I don't have to worry about getting dirty/greasy for doing the actual work.
 
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