bus wont build air pressure - Page 2
 

bus wont build air pressure

Started by goutoe, March 21, 2022, 06:00:02 AM

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goutoe

Thanks Dave, I bought some airline antifreeze that also has some lubricant in it, now I just have to figure out where I can pour it in to the system, I wanted to work on it after work yesterday but the weather wont cooperate! snowing now! but the weekend looks good I will tackle it then. Thanks for the help.
John & Linda 1977 AM General 6V92 turbo Detroit 3 Speed allison, 40 ft.

Tedsoldbus

Hey John,
Keep in mind 12 smart guys are helping you solve this. The 300 other views are people like me that don't have a clue, but we are watching with great interest because it can happen to any of us. Please don't forget to tell us what worked. Guys like me that have been a bus owner for a mere 2 years take notes....
Hope you get it figured out.
Ted
1980 shorty (35') Prevost
6V92  HT 740
Lake Nottely Ga
Bus name "debt"
Education is important, but having a Bus is importanter...

luvrbus

Pull the air intake from the compressor and be sure the compressor is turning after the 15 lb they can strip a drive key and still pump 15lbs of air and a plugged air intake will stop a compressor from building air too
Life is short drink the good wine first

dtcerrato

Ditto what Cliff said - that happened with our compressor - stripped drive and wouldn't pump above low psi.
Dan & Sandy
North Central Florida
PD4104-129 since 1979
Toads: 2009 Jeep GC Limited 4X4 5.7L Hemi
             2008 GMC Envoy SLT 4x4 4.2L IL Vortec

goutoe

Thanks Clifford, the intake would be the hose coming from the air filter housing, correct? I did connect to shop air yesterday, no leaks any where, I still can hear a very faint leak at the air governor coming from a small hole in the casting.
John & Linda 1977 AM General 6V92 turbo Detroit 3 Speed allison, 40 ft.

goutoe

Will I be able to see if the compressor is turning though the intake? how do I inspect the drive key?
John & Linda 1977 AM General 6V92 turbo Detroit 3 Speed allison, 40 ft.

luvrbus

You can see if the unloader valves are working through the intake to inspect the drive the compressor needs to be removed
Life is short drink the good wine first

goutoe

Thanks Clifford! Im going to power wash the compressor before I take the intake cover off, a bit cold for that today hopefully I will find a sticky valve but if I do need to pull the compressor it is very accessible.
John & Linda 1977 AM General 6V92 turbo Detroit 3 Speed allison, 40 ft.

RJ

Quote from: goutoe on March 27, 2022, 12:28:58 PM
. . .but if I do need to pull the compressor it is very accessible.

You have now discovered one of the advantages of having a V-drive powertrain! The alternator and air compressor are literally right there in front of you.

Not like the T-drive folk who have to become contortionists in order to access those items.

My guess is also the compressor drive may be stripped.

FWIW & HTH. . .  ;)

RJ
1992 Prevost XL Vantaré Conversion M1001907 8V92T/HT-755 (DDEC/ATEC)
2003 VW Jetta TDI Sportwagon "Towed"
Cheney WA (when home)

chessie4905

Yeah, but Cliff thinks T drive are the best.😉
GMC h8h 649#028 (4905)
Pennsylvania-central

Busted Knuckle

Quote from: chessie4905 on March 28, 2022, 07:50:18 AM
Yeah, but Cliff thinks T drive are the best.😉

You mean they are NOT? ;D
:D  BK  :D
Busted Knuckle aka Bryce Gaston
KY Lakeside Travel's Busted Knuckle Garage
Huntingdon, TN 12 minutes N of I-40 @ exit 108
www.kylakesidetravel.net

;D Keep SMILING it makes people wonder what yer up to! ;D (at least thats what momma always told me! ;D)

Glennman

Back in my previous bus days ('90s) I had a '68 GMC Fishbowl. We were parked in a Walmart lot in another state and had the same problem. It would only reach about 10-15 lbs. Turns out there was a truck supply outfit right across the street. I was able to get a new governor for about $15 and install it with an adjustable wrench in the Walmart parking lot. It's a pretty good chance that could be your problem.

goutoe

Glennman I have been suspicious of the governor all along I can feel a small amount of air leaking from a small hole in the casing of the air governor I will check the intake as Clifford says, but I will try a new governor before I pull the compressor, My problem now is time to work on it !! hopefully this weekend I will get it figured out, Im also in the middle of installing a washer and dryer in the bus! and my wife is redoing all of the upholstery! I would love to post some pics of the progress but havent been able to figure that out yet!!Thanks to all of you for your help and concern! you guys are awesome, bear with me with your help I will get this Fixed!
John & Linda 1977 AM General 6V92 turbo Detroit 3 Speed allison, 40 ft.

chessie4905

Be careful with new governor. There are 4 holes, I think, and a set of Allen threaded plugs. Be sure to get them installed in same ports as old one.
GMC h8h 649#028 (4905)
Pennsylvania-central

goutoe

well back to work on the bus today, checked the intake hose it was clear, took the intake housing off ran the engine no movement on the valves still only 15 psi so next is to pull the compressor, never done that before, I suppose it is on a spline? what do I look for next?? is there a key way?
John & Linda 1977 AM General 6V92 turbo Detroit 3 Speed allison, 40 ft.