| Author |
Message |
Lin (66.245.216.207)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 02, 2004 - 8:40 pm: | |
A couple of weeks ago I posted a question on a different board about my GMC Superiors air system. It seems that in the years I have had it, the system always aired up to 90 psi and I had never thought to question it. When I mentioned it, I was told it should be at 120 psi and that I should do something about it. Well I did. I found that my compressor had a governor/release system that was adjustable. There is an about 7/8 inch plug on the right rear. This had a spring and a plunger beneath it. When the set pressure is reach, air is released through this mechanism in rapid short bursts. If one tightens the plug, increasing the spring tension, the release pressure is raised.
Now the new question. I have tightened it to the point that it vents at about 120 psi, but find that in the range from 100 psi to 120 psi, there is leakage through the system. It is not massive. I do not think that it adds much to the work of the compressor, but I can hear and feel it if the engine is off. Is this something that is okay to ignore, or is there an efficient fix for it? Efficient means I have no desire to change the compressor over it. |
TWO DOGS (65.177.145.73)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 02, 2004 - 9:37 pm: | |
D-2 air govenors are about 25.00......good to have a spare....all I have ever installed were pre-set at 120....is that where the leak is ? |
Lin (66.245.216.207)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 02, 2004 - 9:57 pm: | |
Does that mean that I have just been removing the inards and that there is a whole unit I should be taking out? Visibility is very limited so I have been using the peek-and-feel method> |
TWO DOGS (63.185.81.90)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 02, 2004 - 10:54 pm: | |
yeah.....go into a truck supply or even a truckstop and tell them you want to buy a d-2 air govenor |
BrianMCI96A3 (67.77.37.160)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 03, 2004 - 9:57 am: | |
"...air is released through this mechanism in rapid short bursts."
Well, that statement doesn't sound quite right to me ...
What year is your Superior?
Depending upon the year of your bus your air system may not have an air dryer, that MIGHT be the reason for the pulsing of the governor...
While 120 psi is normal system pressure in a modern air system (certainly anything newer than 1975)... I wouldn't neccesarily be surprised if an older vehicle has something different, nor would I be at all surprised to find that someone in the past turned the governor down to 90 psi because of the air leak you are hearing at 120!
Because as Two Dogs mentions the D-2 governor is very inexpensive I would recommend replacing it, that is the mechanism you are dealing with.
It is held to the compressor via two bolts and can be replaced in under 15 minutes in most instances .
Brian |
TWO DOGS (63.185.72.198)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 03, 2004 - 12:58 pm: | |
HERE ...is the secret tho...once you get those two bolts off....LOOK at the unit & plug the SAME holes in the new unit...then put the two bolts in...& it's done |
Lin (66.245.216.207)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 03, 2004 - 5:31 pm: | |
Well, I finally got a little more sense and checked online to see if could match a picture to what I have. It appears to be a Midland "18500" governor. It does not look like it is interchangable with a D-2. Does anyone have any experience with one of those? |
BrianMCI96A3 (67.77.37.160)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 03, 2004 - 7:54 pm: | |
Midland, in my opinion, is a lesser product, but they do well enough I suppose, if you take it to the your local truck parts place the counterman should be able to determine if the Bendix D-2 or other replacement governor will fit your application.
Brian |
Henry R. Bergman, Jr. (Henryofcj) (63.224.197.10)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 04, 2004 - 7:06 pm: | |
No disrespect intended and I know that with my coach, I try not to mess with the air brake system. Instead, the local heavy duty truck mechanic air brake specialist does it and I just pay him the $bucks$. Good luck. |
BrianMCI96A3 (67.77.37.160)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 04, 2004 - 9:42 pm: | |
Well, Henry, under normal circumstances I'd have to agree with you, an amateur fooling around with the brake system can be a real disaster but in this case, as a diesel mechanic, I'd have to believe that this particular job requires a relatively low skill level. I trust that Lin will insure that he matches the old governor port for port and tightens the bolts that hold it properly.
Brian |
Lin (66.245.216.207)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 05, 2004 - 12:05 am: | |
Yes, it's probably better that I don't mess with many things that I do. I usually find that out when I am deep into it. I was able to order a replacement governor. This one is no longer made so a had to pay about 4 times the cost of a D-2 including delivery. It is due in tomorrow, and I hope it's the right one. Anyway, switching it out looks pretty straight forward though I have said that before and been suprised. But if it requires a low level of skill, I'm right for the job! |
Niles (4.4.124.153)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 05, 2004 - 12:41 am: | |
Lin,
If it required no skill at all - I'd come help you out (wink,wink) - LOL - Niles |