Page 1 of 1

GMC Savannah Bus - A/C - FIXED

Posted: Mon Jul 23, 2012 12:55 pm
by asample
Sorry I have not posted this earlier. Wanted to make sure that it stayed fixed and I have not spent much time in the office since my last post with being out of town to help my sister celebrate her 50th wedding anniversery, then took an Alaska cruise. The day we got back our daughter, son-in-law and grandkids spent a week with us.

Anyway, back the subject.

The underhood label from the bus manufacturer called for 5.5 pounds of refrigerant, which we were charging to. The first two compressors would not develope pressure or suction on the bench. The third compressor, a different manufacture, would develope pressure and suction on the bench but still got same results as far as pressures and air temp when installed.

We decided to slowly add refrigerant to see if anything would develop. It slowly started to cool and pressures came to normal. It finally functioned well after charging with 10.5 pounds or refrigerant.

Live and learn I guess.

Re: GMC SAVANNAH BUS AC -- FIXED

Posted: Mon Jul 23, 2012 12:58 pm
by brianp87
funny you say that just had a 2011 ambulance in that after its new motor was onde at ford it wouldnt cool. They charged to label and it was wrong also . Guess they should have tried it on a road test.

Re: GMC SAVANNAH BUS AC -- FIXED

Posted: Mon Jul 23, 2012 12:59 pm
by brianp87
Nice job finding it

Re: GMC SAVANNAH BUS AC -- FIXED

Posted: Mon Jul 23, 2012 2:10 pm
by liljoe
brianp87 wrote:funny you say that just had a 2011 ambulance in that after its new motor was onde at ford it wouldnt cool. They charged to label and it was wrong also . Guess they should have tried it on a road test.

I have found that over half of the labels on the ambulances I service are incorrect......... The funny thing is that the labels are put on by the ambulance factory and not by Ford/Chevy/Dodge.......

Re: GMC SAVANNAH BUS AC -- FIXED

Posted: Mon Jul 23, 2012 2:12 pm
by brianp87
Exactly they dont even know how much it takes and they built it. But if the dealer would have tried it they would have known it wasnt cool. Doesnt take long in arizona to tell.

Re: GMC Savannah Bus - A/C - FIXED

Posted: Mon Jul 23, 2012 5:58 pm
by brother bubba
Seems like an old fashioned sight glass would be helpful on these after mod systems. Seems like I remember a church bus a few years back. Thanks for reminder .........

Re: GMC Savannah Bus - A/C - FIXED

Posted: Tue Jul 24, 2012 1:32 am
by steven kiser
:lol: :lol: :lol: sometimes the shop with the guy that just adds until it gets cold wins. Doesn't it stink when we have to revert to cave man tactics. Glad this one has been put to bed.

Re: GMC Savannah Bus - A/C - FIXED

Posted: Tue Jul 24, 2012 5:02 am
by liljoe
steven kiser wrote::lol: :lol: :lol: sometimes the shop with the guy that just adds until it gets cold wins. Doesn't it stink when we have to revert to cave man tactics. Glad this one has been put to bed.
I even look like a cave man....... I like to try to charge by specs, but sometimes on custom stuff, it just don't work that way. Sometimes you just have to use your experance and gut to fix things.....

Re: GMC Savannah Bus - A/C - FIXED

Posted: Tue Jul 24, 2012 5:07 am
by ricmorin
I did one once on a firetruck. It had a sight glass and I used that instead of the spec decal. It definitely took more than the label said. Good find.

Re: GMC Savannah Bus - A/C - FIXED

Posted: Tue Jul 24, 2012 6:36 am
by asample
Glad I'm not the only one that has been stymied by this situation. Just wish it hadn't taken me so long to find the solution. When the first two compressors could not be coericed to produce suction and vacuum on the bench it just seemed logical to suspect the compressors.

Lessons like this are learned well and remembered.

Thanks for the advise and encouragement.