Author Topic: Governor  (Read 9221 times)

Offline John316

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Governor
« on: October 12, 2008, 06:55:25 PM »
How do you adjust the air governor. We want our air to stay between 115 and 120. It doesn't kick the compressor on soon enough when we are in traffic. It drops to maybe about 100 then the compressor starts and brings it up. I want it to kick the compressor on between 110 and 115 to bring it up to 120 or 125. I know that is a little tight parameters, but in traffic you don't want to get at all low. I just don't know how to adjust the governor. I think that there is two screws on it, but I haven't looked closely yet.

Any suggestions of pointers would be great. I am still learning. :)

God bless,

John
Sold - MCI 1995 DL3. DD S60 with a Allison B500.

Offline white-eagle

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Re: Governor
« Reply #1 on: October 12, 2008, 07:02:23 PM »
i haven't had a problem with my governor and i'd be a little concerned about having my compressor running each time i hit the brake.  i've been in some traffic jams, but no problems or even close.

i'm sure that didn't answer your question, but i think it obviates the need for doing anything.
Tom
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Offline niles500

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Re: Governor
« Reply #2 on: October 12, 2008, 07:06:12 PM »
To adjust the D-2 take the cap off the end, free the locking nut and rotate the set screw (I think clockwise) to increase the set PSI - max PSI is 130 PSI +/-    HTH
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makemineatwostroke

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Re: Governor
« Reply #3 on: October 12, 2008, 07:41:29 PM »
John316; what you trying to do can not be done with a governor adjustment if it set at 120lbs it will not kick in till around 105lbs.The only way is take it to a air brake specialist and he can do with the unloaders on the compressor but it won't be cheap     

                                have a great evening

Offline buswarrior

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Re: Governor
« Reply #4 on: October 12, 2008, 09:24:25 PM »
Your typical air system governor will operate the air system over a 20 to 25 lb spread between compressor cut-out and cut-in.

The numbers you quote sound fine to me, and your air system is functioning normally.

Now, as to what your air consumption rate might be....

Often, those unfamiliar with air brakes use far too much brake pedal, and hence, too much air waste, for a lot of stops. Try to feather back on the pedal and at all times of brake pedal use, you only squeeze down the absolute minimum to get the job done. The amount of pedal used to hold the bus stationary is often the worst waste of air.

Does the system leak? With the air system full, with the parking brake released, and foot on the brake pedal to the floor, turn off the engine and watch the air gauge. If it stays still for one minute, great. If it is dropping, not great, go get those leaks fixed, they all add up to compressor run time, and air not being available for the brakes.

Or, another way, your air system should stay full/within the governor range running down the interstate indefinitely unless there is some air consuming feature operational.

Way too many busnuts have been fooled by someone into thinking air leaks are acceptable. Constant cycling of the compressor shortens its life, and depending on where the air is leaking, and the rest of the air system maintenance, leaks could be dangerous as the brakes could be compromised under the right failure conditions.

Good for you in wanting a good supply of air!

happy coaching!
buswarrior
Frozen North, Greater Toronto Area
new project: 1995 MCI 102D3, Cat 3176b, Eaton Autoshift

Offline BJ

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Re: Governor
« Reply #5 on: October 12, 2008, 10:39:31 PM »
 ;D taint nothing wrong with your air system. If it ain't broke don't mess with it  ;D

Offline Sojourner

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Re: Governor
« Reply #6 on: October 12, 2008, 10:53:46 PM »
Read the link about D-2 Governor:
http://www.bendixvrc.com/itemDisplay.asp?documentID=2382

You can change pressure setting but the pressure range between cut-in and cut-out is not adjustable.

FWIW

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Dreamscape

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Re: Governor
« Reply #7 on: October 13, 2008, 02:53:07 AM »
Leave it alone! ;)

The more your compressor runs to keep up with such tight settings will just cause more condensation, which is water.

The settings you have are just right, I would suggest not to mess with it!

The following Bendix link is one I found the other day and it has been most helpful.

https://www.bendix.com/EN-US/SERVICE/LIBRARY/Pages/SDSheets.aspx

Everything about Bendix applications that most of us have is there.

By the way, if you have a manual it should describe how do adjust your govenor, mine did.

HTH,

Paul

Offline John316

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Re: Governor
« Reply #8 on: October 13, 2008, 09:16:43 AM »
Thanks guys for the input. Yes we do know how to use the air brakes (read books and looked at courses, talked to truckers and busers, and we have gone through all of the DOT book on CDL etc.). That makes sense about the parameters. We haven't had a problem yet, but I didn't want to have any problems with running out of air. We don't have any major air leaks (we are finding them and fixing them), except for overnight, when the air bleeds down a ways.

Just shows how much I know about the governor ;D. The 120 is fine but if I can't adjust the parameters that is okay.

I was also wondering if I could bump the governor to 130 or will that be hard on the air components?

Buswarrior, great words of wisdom. I will check on if we have any leaks the way you described, I don't think we do but we'll see. I agree with what you say about the least amount of pressure on the pedal to do the job, but there is a lot of times that little car that thinks they can squeeze in the gap right between your bumper and the car in front :(. Our dryer purges rarely as we are driving on the interstate so that is also a good sign.

Sojourner and Dreamscape thanks for the sites, good info.

God bless,

John
Sold - MCI 1995 DL3. DD S60 with a Allison B500.

Offline buswarrior

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Re: Governor
« Reply #9 on: October 13, 2008, 09:22:35 AM »
Yes, you may up the cut-out to 130 lbs with no ill effects.

Mine is up close to that, and a great number of the newer equipment are leaving the factory up at 130 lbs.

Designed use standard for the components is 150 lbs, with the burst point way up over 300, so you'll be fine at 130.

happy coaching!
buswarrior
Frozen North, Greater Toronto Area
new project: 1995 MCI 102D3, Cat 3176b, Eaton Autoshift

luvrbus

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Re: Governor
« Reply #10 on: October 13, 2008, 10:04:16 AM »
John, one thing about going from 120#s to 130#s it will help find the weak points in your system on a 20+ year old bus, shoot man it may help by creating others for you to repair (did for me)    good luck

Offline Utahclaimjumper

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Re: Governor
« Reply #11 on: October 13, 2008, 11:05:16 AM »
Pulling water and other waste out of your tanks also makes a huge difference in available when needed, any water in the tanks displaces air that you may need.>>>Dan
Utclmjmpr  (rufcmpn)
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Offline John316

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Re: Governor
« Reply #12 on: October 13, 2008, 12:55:18 PM »
Thanks I will adjust it up to 130.

Dan our tanks are very clean. I have drained them regularly and I haven't gotten anything yet.

I checked and we don't have any leaks in the system.

God bless,

John
Sold - MCI 1995 DL3. DD S60 with a Allison B500.

makemineatwostroke

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Re: Governor
« Reply #13 on: October 13, 2008, 01:07:35 PM »
John316; i don't know what make or model of bus you have but before i started changing the air pressure there may be a reason the air pressure is set a 120lbs consult your owners manual. have a great day

Offline Hartley

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Re: Governor
« Reply #14 on: October 13, 2008, 02:02:56 PM »
I would hesitate to fool with the pressure.
You will find a nasty series of problems if the air-bleeder for the filter/drier
is weak. The pop-off ( over Pressure valve ) may get tripped because of a weak spring (old) and won't kick back in until (and if) the presure drops to almost nothing. I had the same problem when I ran my air pressure to 130 psi and it went away when I went back to the 120 psi. The other thing to remember is that old air tanks get weakened by internal rust. Demanding that they hold more pressure than they normally hold is pushing the chance of failure way up.

If you blow a tank you are in a heap of trouble that you really don't
want to deal with on the road.

The older coaches have some quirks especially after years of use and abuse.

Good Luck.....

Now if I could figure out where I parked all will be great...(hehhaaa)...
Never take a knife to a gunfight!

 

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