| Author |
Message |
g
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 11, 2005 - 10:03 am: | |
I have an older dash air gauge with two indicators. The green is the total bus air (start up) and the yellow indicator is the set shut off at 120 psi. So, I had to rebuild the dash and need to reattach(not working when purchased) I have bus air coming to the gauge. It looks like the green side actually sends air over to the yellow side. Any ideas. There are no manufactures markings on the gauge. Just a port for yellow and a port for green.
FYI, original manual is no good for this question or I would not have asked!
Thanks
G |
truthhunter@shaw.ca
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 11, 2005 - 10:32 am: | |
The second indicator is for appied presure or shat you are putting on the brake application with the foot valve, useally. |
g
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 11, 2005 - 10:59 am: | |
Does the applied pressure port come of the main line? A loop as it were? |
RJ Long (Rjlong)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 11, 2005 - 11:01 am: | |
What you're holding is known as a "Dual Air System" gauge. Green is for the primary, yellow is for the secondary. Corrollary in the automotive world would be your dual master cylinder on the brakes.
There is what's called an "inversion valve" in the system, usually located on a rear bulkhead by the back axle. If you have a catastrophic loss of air pressure in the primary system, the inversion valve flips over internally and supplies air from the secondary system to the brakes to get you stopped safely.
That's the concept.
As for actually plumbing the gauge, I'd suggest contacting Bendix tech support, since they're the biggest supplier in the HD industry. There might be a schematic on their website, not sure, but here's the link:
http://www.bendix.com/troubleshooting
If you can't find one on the troubleshooting page, perhaps using the "contact us" link and asking for a schematic might get you what you need.
Another idea, if you have a transit agency nearby, is to talk to the shop foreman, and see if he'd help you figure out the plumbing by viewing one of their coaches either on a lift or over the pit, along w/ a technician who's familiar with the system. Six pack might help, too! Or a charter bus outfit.
Same idea, but at a HD truck dealer, since the plumbing is similar.
HTH,
RJ
PD4106-2784
Fresno CA |
g
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 11, 2005 - 11:28 am: | |
RJ, Thanks and I will check the sites and see what they have.
Regards,
Grant (Sacramento) |
Chuck Newman (Chuck_newman)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 12, 2005 - 11:54 am: | |
RJ,
I have two questions related to this issue:
1) My 102A3 and all the other's I've seen have a single needle 3-1/2" air gauge next to the speedometer. Apparently it is looking at primary air only. I plan to install a dual gauge to monitor primary/secondary air. My question: is this single system monitoring of air pressure common to busses? All the trucks I've seen and a past commercial motorhome I had all had/have dual system gauges.
2) I plan to install a separate brake pedal pressure gauge. Does that usually connect to one of the air out ports on the multi-port valve mechanically connected to the brake pedal (I can't remember the name of the valve)?
Thanks,
Chuck Newman
Oroville, CA |
Buswarrior (Buswarrior)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 12, 2005 - 3:31 pm: | |
Hello Chuck and Grant,
See my post over in the recent "air pressure" thread.
Chuck, your air gauge is not plumbed into half the brake system, unless someone has done some serious and arguably unsafe modifications to your under-dash plumbing.
On an older single circuit brake system, someone could try to use a newer dual needle gauge for a combined air supply and brake application gauge, however, the application would not move very far, as a typical stop at the stop sign only takes somewhere around 10 pounds of applied air pressure to stop. So, it wouldn't be very good at all...
happy coaching!
buswarrior |
t gojenola
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 12, 2005 - 9:58 pm: | |
I have a dual gage in my 4106 that I salvaged from a new flyer. I didn't intend using the secondary portion at all since I don't have a secondary air supply. I toyed with the idea of using it for a brake monitor, but ended up hooking it into the delivery side of the air throttle. Tells me a lot about the actual throttle position that I would not otherwise know. It helps a little with the black smoke and shift-point management (v730). Plus, its fun to watch..
tg |
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