Jake brake, anti-lock brakes, '05 Int'n'l Dump Truck

[Jack-the-Ripper]

This is the newest vehicle I own; lots of computer stuff!

The Jake brake isn't working. Its activation switch gives an incorporated flashing light instead, when activated.

The manual says that during the need for ABS activation, the system will override the Jake. I suspect there may be a connection.

The ABS light for the 4400 series truck should come on with the key switch, flash during initial system startup and checks, then go out. Instead it just comes on and stays on. The Jake problem had a couple of intermittents, then refused to work, all about the same time as the ABS light issue. I started looking at the instrument lights when I got a check engine light that coincided with a cooling water leak from the "plastic" overflow tank that I first spotted on the ground. There are no trailer ABS issues.

The overflow tank has a low radiator water switch. The water/antifreeze was still between the sight marks (as I recall) and shouldn't have indicated (I don't recall a cooling water light ever showing). After the radiator tank replacement, the check engine light is now off, yet Jake and ABS still remain inactive.

Otherwise the truck seems to operate just fine.

I'm suspecting there might be some coincidental "connection" for all this through the computer(s). I've read on line that there might be a way of resetting some ABS units with a magnet (it trips an internal "reed" switch)(not necessarily or specifically for my truck yet). I've also read that trouble codes might be available either through a flashing ABS light (when some obscure button is pressed) or through the electronic odometer when some cruise control buttons are pressed (although some opine that this is only for engine problems).

I've done the usual Google searches to get this far. I've briefly searched the maze of wires and hoses on the truck to check for broken wires.

The very busy dealer is 60 miles away and I'm trying to avoid the long truck drive, getting back home after leaving the truck, and then having to reverse the logistics to pick it up again.

Any ideas or suggestions for where else to look?

[Steven Walters]

Check All fuses! Is there any way coolant leak shorted any wires/connections out? I had abs issue and it was ignition fuse. I'm not familiar with int call service Ask how to check sencers on each wheel usually just ohm meter check resistance.

[Willyr]

I would suggest a different forum for this question. (sorry Lavoy, dont mean to trample on rules here)

The place I recommend is....
http://www.thetruckersreport.com/trucki ... -wheelers/

I frequent this forum quite a bit with the name lovesthedrive. You are dealing with truck owners and the mechanics. If it were a freightliner I may have a clue, yet since it is a pornstar, I cant help you. Pornstar refers to the International line of trucks (prostar). Lots of plastic, not much to them.

Good luck!

[mapaduke@yahoo.com]

I'm not an expert but I have a 01 International with abs no jake and one of the sensor bracket on the rear axil rusted enough that it lost contact with the rotter .I never new that they weren't working until it went in for state inspection. The light on the dash was very dim. Now that they are working I can hear the solenoids clicking in an out when you start it up.
Hope this helps Ron

[Jack-the-Ripper]

Great suggestions, one and all. I know that asking here is a long shot but there's so much talent, I thought I'd give a try.

The coolant just dripped straight to the ground. It doesn't seem like it should have any connection to the Jake (but always good to keep in mind). In my years of troubleshooting I like to put everything strange and coincidental on the table and sort it out from there, even if it doesn't make sense at first.

My thought was somehow(?) the coolant triggered the check engine light, and somehow (again) the engine computer and ABS computer "tripped" over each other(?) and got into a "lockup mode." (Like too many apps open at once on my laptop can do.) The ABS should only override the Jake during a wheel lockup - so I'm thinking the ABS computer(?) is stuck in that mode thereby holding off the Jake. I'm strongly influenced by the fact that ABS doesn't go through its startup routine either. I can't help but think that its probably something simple for someone who knows all the systems (like an Int'n'l mechanic).

As with lots of us here I suppose, I hate to pay someone else for what I usually can fix myself, and then they get the learnin - not me!

I think I've found the ABS computer under the hood on the fire wall next to all the air hoses right behind the clutch (that statement makes me feel like I should go back to playing with Leggo's). I'll try the fuses, relays, ohm meter test, and the other truck site. And spend some more time on my back underneath her looking for some obvious break - on a nice sunny day!

All in all I've been happy with the truck so far (plastic not withstanding) - its a step up from my first one, an '82 GMC General - what a beater - but a good one to learn about shifting, and a strong "heart."

The '05 has a strong DT530 and 10 speed, and its nice that the dash board doesn't fall off and the A/C works. Sure makes it easy to haul the 450s around.

Thanks again for the input.

Ralph

[digitup2]

Try your ABS relay Jack I don"t know if it is a five prong or a four prong relay plug but replace it with the same relay unit and see if things change good luck .Digitup.

[leadfoot1954]

you can also check under dash for a contact switch on clutch pedal;i have driven pete's and kw's that had this switch go bad and disable the jake brake.computer thinks clutch is disengaged and won't close circuit.also try wiggling all abs leads at each wheel,as they get dirty and send a fault code

[Jack-the-Ripper]

Thank you all for the fine suggestions.

I replaced the "plastic" overflow tank for the cooling system which cured the leak but did nothing for the ABS light or the Jake, at a cost of about $300 for the part - ouch! At least my labor was free.

The ABS computer was indeed on the fire wall, between the fuse box and the "air brake manifold." The fuses and relays all checked out OK. I had to remove the computer and clean off all the dust before I realized it simply has a row of lights along its top edge to indicate the various trouble states. It showed a right rear wheel sensor problem.

I checked the sensor at the wheel, at the computer through the sensor's wires, and the resistance of the wires otherwise disconnected, all for opens, shorts, grounds and proper resistance - all was within spec. I took the wire from the left rear wheel sensor and put it on the right rear wheel sensor. If the RR wheel sensor was bad, I should now have shown a LR wheel error - I did not. I reversed the wiring to the LR wheel sensor and showed no problem. I reconnected everything to "factory" and held a magnet briefly next to the "reset" word on the computer. The lights made the computer seem like it was briefly having a seizure. After all this, the ABS light on the dash remained dark, I could again hear all the relays as the ABS self-checked, and my Jake worked again.

In conclusion, apparently any trouble condition of the ABS system locks out the Jake Brake,

I apparently "fixed" the problem, but never noticed a direct cause and effect relationship with anything I did,

I hate it when this happens, yet I accept it. I've had this happen before in my life, and attributed it to my "magic healing hands" - hardly a proper topic for a PhD Physics thesis topic. Realistically I attribute the "fix" to moving everything around, and good fortune.

I didn't mention that the AC (air conditioning) light has also remained on. My AC mechanic friend did a thorough diagnostic of the system - we've got the AC working fine and have yet to determine why the light stays on.

I had found a chart on line that explained the ABS system computer and its vagueries. I've yet to purchase the manuals necessary to understand all the truck's systems. For now it is running fine, and cool. Can't ask for much more.

Again, thanks for all the suggestions, encouragement, etc.