07 M2 parking brake light and low air buzzer issue???

[RETIDEPXE]

I had a freightliner dealer in Columbus tell me they did not have time that day to install mine (4 hrs. to close) so I went to their parts department, bought one and installed it in their parking lot before I left. No one said anything.

 

[Skyline]

awayne,
When ya get back to your computer hope this helps,,and don't ask me why I still have this in the truck with me but I do..
Numbers on old valve is..
SWB A12-19777-203
Part # on my invoice is....
NGR/27SWB303R SWITCH-AMU Park. NO PSG
Cost was $53.41
Hope it helps ya.

Mine reads SWB-A12-19777-003 and not 203, but I assume they are the same. I bought the left one yesterday, installed it today, did not work (being the wrong one), reinstalled the old to return it for the correct one after reading this thread, put it on the ground, moved the truck forward 5 feet and drove over the new unit. At least I am home and its Friday! Stupid does not even begin to describe the feeling. Be safe out there. Lenny

 

[Slo-Ride]

Mine reads SWB-A12-19777-003 and not 203, but I assume they are the same. I bought the left one yesterday, installed it today, did not work (being the wrong one), reinstalled the old to return it for the correct one after reading this thread, put it on the ground, moved the truck forward 5 feet and drove over the new unit. At least I am home and its Friday! Stupid does not even begin to describe the feeling. Be safe out there. Lenny

Not sure what ya mean by the left one..The valve that caused my troubles was located closes to right side of the truck..With-out crawling under I beleive it is the last one and kinda standing alone..Not connected to the larger block of valves.???? Maybe thats reason for different part#.??

1 bright side to ya running over a new part is ya didn't pop a tire...

 

[RETIDEPXE]

Just an update....

I replaced the AMU for the parking brake and it resolved the issue. I did it myself in about 1 hour and could actually do it quicker now that I have done it once. Beats paying Freightliner $100+ to do it.

Congrats Awayne on DIY. I posted on another thread hear somewhere about this. When replacing the "rack" of AMU's, place a wide enough slide clamp on them to squeeze them together tight so the rubber gaskets are well seated. Oh, and before using the clamp, be sure the retainer clips are installed correctly (easy to misalign them) and give them a light tap to make sure they are seated well. Leave the clamp on while you bolt the angle iron bracket back on to hold them in place. I too had problems with mine until i tried this some 500,000 mi.s ago and haven't had a problem with them since. My theory is moisture finds it way into the AMU's causing most of the problems, along with the gaskets giving way. Use info at your own risk.

 

[Skyline]

I had the low air buzzer last year and replaced the big square valve on the driver side that fixed the problem. Now my brake lights started giving problems on my way home and has completely stopped working. I have checked everything that I can. Does this valve also double as the brake light switch? Any input would be greatly appreciated.

Those AMU's go out on a regular basis. They are junk. Mine costs $249 plus labor. It goes out every 6 months to a year. I have to have mine checked in a couple of weeks. It is going AGAIN. It has not been six months, the warranty should cover this one.

 

[fr8hlr521]

Had a similar problem on our 08. It was a corroded ground wire to the rear lights at the back left corner, just under the box, by the ICC bar. There may also be a fuse block underneath the truck near the tranny for the box lights and rear lights. Our has one there.

 

[Skyline]

Thanks. Working my way through it all.

 

[RETIDEPXE]

Yes, if I remember correctly the brake lite switch AMU is different then the low air warning buzzer. I've had to replace my brake lite switch once in 1.1 million mi.s on my '07. REally a safety issue because the cruise will not disengage when you hit the brakes, spooky feeling. I pulled the cruise fuse 'till the brake light AMU was replaced.

I also had a wire corrode somewhere between the body module under the cab and the brake lites, never could find it. Freightliner Texarkana charged me $1,000 to fix one wire and killed my batteries to boot, and I've been patching up other corroded wires where they probed a test lite hole and didn't bother to seal up with liquid tape afterwards smh.

 

[KSommers]

CHECK THE BRAKE FLUID LEVEL

Hello everyone. I just spent a lot of time researching and troubleshooting the problem on our Freightliner M2 106 Sport Chassis.
The brake light and buzzer would come on while driving. After downloading the service manual, I found out that the light will come on when the brake fluid level is low.
The level was right at the sensor so when I would turn left or brake a little hard, the fluid would slosh away from the sensor causing it to set off the alarm.
The fix was so simple it was a little embarrassing how much time I spent on it.
Hope this helps.

Have a good day.