It's on a '64 GM PD4106.....located on the engine firewall to the left of the oil pressure sending unit and the low oil pressure switch. It's wired along with the stop light switch circuit. When you apply the brakes, it get's 12 volts just like the brake lights. The air line curving beneath it tees into the left side and then provides air to the stop and fast idle solenoids....on the other side an air line exits, turns 90 degree down and is the straight line you see behind the curving air line. I can't follow the straight line because is dives through the firewall and I don't feel like jacking and blocking to see where it goes. I see no reference to it in my manual or supplement, but I know the later model 4106s had some alterations in some areas. Any ideas?
(https://lh5.googleusercontent.com/-cCV2bgNeDr0/TmKhxkoE-PI/AAAAAAAABD8/1A7GOXQ5W7k/s288/IMG_20110903_131639.jpg)
FWIW,
#674 does not have that....
TM
Thanks, I may try troubleshooting by killing the power to it and see what happens.
FWIW, another '64, #??? doesn't have it.
My 4106 has two of these one controls the fast idle the other is the engine governor control. I don't think it will run without it. the 62 4106 also had two.
Papatony - Maybe you're confusing the "bwze mystery valve" with the two standard solenoid valves which are located further towards the driver's side?
Ted
I'llheck it again
I didn't get a chance to do any further troubleshooting. I may get some time this week.
I think that the fast idle only works when you are sitting still. Maybe that "do-dad" is what makes that work on your bus. If you release the parking brake or put it in gear it will return to regular idle speed.
No, I wrestled with that a few months back. There's a pressure switch that works with park brake valve located in the tool bay beneath the drivers seat that controls the fast idle relay.
This thing only sees power when the brake foot pedal is pressed and the stop switch closes.
Could it have been for a trailer brake controller? Perhaps the line that disappears, terminates at the rear bumper?
In my bus manual - an MCI, but still - there is an option for Expello moisture ejectors on the air tanks. The moisture ejector is air-controlled by a Skinner valve that is controlled by the brake light switch. I bet that's it, if you have a moisture ejector or used to have, anyway.
Brian
Len, the line is headed back towards the front, so I'm thinking that may not be it.
bevans6, that makes a lot of sense.....now I want to block and jack just to see where it goes.... ;D
Bill -
I'm not sure what that is either, my '64 didn't have it.
Perhaps a call to Luke, with a request that he look at this thread, might help solve the mystery before you start crawling around underneath?
1-888-262-2434 between 9 - 5 M - F Eastern.
FWIW & HTH. . .
;)
Long shot here, how about supply to an air actuated toad braking system?
TM
DON'T MESS WITH IT IT FOR THE EJECTION SEAT
:o
Rick 74 MC-8
passenger Air Bags.....
I followed RJ's suggestion and gave Luke a call earlier today. He must have gotten busy because he never got back with me. Anyway, I decided to try to trace it out myself. The air line that exits this device on the right runs through the firewall and makes it way up to the center chase in the ceiling of bays of my '06. From there I have no idea where it ends up because I can't easily remove the chase cover to follow it any farther. I assume it must exit the chase near the fuel tank compartment, but I can't see to know for sure. I did get my wife to apply the brakes for me and it is definitely a solenoid of some type because it engaged once. Now I got her to apply the brakes a few times, but it only felt like it engaged the first time, but I could be wrong about that. So, I'm still confused........most of me says if it ain't broke don't fix it, but then what if it does break and I don't know what the heck it is.......;D
Talked with Luke today and he had one of his mechanics call me back. He and I talked for about 10 minutes or so and couldn't come up with an explanation for this solenoid valve. So when I got home today, I decided to jack up the front end so I could get a better look at where the line looked like it was headed and found where it exited the chase that runs down the middle of the bus.........but the end of it is plugged. Also, right by where it exited, there is a spot on the wall beside the wet tank where it looks like something used to be mounted. The studs are still there, but whatever it was is gone. So I guess that means that the mystery is for the most part solved. :)
That probably would have been the moisture expeller valve mounted near the wet tank like that, operated by the Skinner valve. Cool...
Brian
Yeah, I thought so too. If so, wish they wouldn't have removed it..... ;)