What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[Geotrash]

Is the consensus to not add any oil unless replacing large parts?

That's my understanding. In the video I linked above, he speaks to that at about 7:30.

 

[89Suburban]

From all I've read, the gauges on those cans are a gimmick and it's easy to overcharge the system with one, so I bought a set of gauges, a postal scale and a vacuum pump, and learned to do it by weight, which is what GM specifies. My 2007 Yukon XL Denali w/ rear A/C takes 40 oz. Took me about an hour to do the job - 45 minutes of vacuum, and 15 minutes to charge the system. It was empty due to a leaking Schrader valve on the low pressure port, which I fixed, so I didn't have to worry about recovering the old refrigerant. If it still had the refrigerant in it, I would have taken it to a pro to have the work done so they could recover it for recycling. As the system was charging, I kept a thermometer in the dash vent and once I'd added the 40 oz., the temperature was 1-2º colder than spec.

Apparently, not doing it by weight has implications with these trucks because the compressor sits low in the system, where excess liquid (like having too much oil in the system) will accumulate and can eventually take out the compressor. Dunno how true that is in practice, but it's what I was told by a mechanic friend.

Anyway, I did the job 2 years and 20K miles ago and it's still blowing ice cold with no other problems. This video was the guide I used. Good luck!

That gauge set is nice. Has the window in it and purge valve so when you hook up a new can you can purge the air out of the line and see the fluid in the window.

 

[89Suburban]

Is the consensus to not add any oil unless replacing large parts?

Yes sir.

 

[89Suburban]

My parking brake warning light disappeared off of my gauge cluster. Is there a sensor for this on the pedal assembly somewhere or a way to troubleshoot that?

Any insight on this guys? The light comes on during the key on test cycle. But when I set the parking brake it is not lighting up.

 

[George B]

Any insight on this guys? The light comes on during the key on test cycle. But when I set the parking brake it is not lighting up.

There must be a switch on the pedal assembly.

 

[wjburken]

Any insight on this guys? The light comes on during the key on test cycle. But when I set the parking brake it is not lighting up.

You may have a bad parking brake sensor switch that's not detecting when the brake is engaged.

 

[Doubeleive]

Any insight on this guys? The light comes on during the key on test cycle. But when I set the parking brake it is not lighting up.

apply the parking brake, then look down around the assembly there is a switch they used to be a push button but it's probably a contact switch, might be hard to see but it's there. check it to see if it's stuck or if the contacts are dirty, got bent, etc.

 

[wjburken]

Any insight on this guys? The light comes on during the key on test cycle. But when I set the parking brake it is not lighting up.

It should look something like this if I'm not mistaken.

 

[89Suburban]

There must be a switch on the pedal assembly.

You may have a bad parking brake sensor switch that's not detecting when the brake is engaged.

apply the parking brake, then look down around the assembly there is a switch they used to be a push button but it's probably a contact switch, might be hard to see but it's there. check it to see if it's stuck or if the contacts are dirty, got bent, etc.

It should look something like this if I'm not mistaken.
View attachment 366307

Thanks guys I'll take a look under there and see what the deal is when I get a chance.


GD door lock just stopped working on my D/S/F door. She's been a real B*TCH this year so far with things breaking.

Fuel pump replace, rebuild rear axle, 2 fuggin DL actuators in 3 months. Both of those are only a couple years old too.

 

[Doubeleive]

It should look something like this if I'm not mistaken.
View attachment 366307

probably depends on the year they changed the parking brake design, not sure what year, my 12 is a push to engage, then push to dis-engage, the older one's have a traditional pull handle release with cable.