Fixing the Air Conditioning - What a Nightmare!

[Gregski]

In this episode of the "What a Nightmare" series, The Greg tackles the air conditioning system on his beloved 1997 Chevy Tahoe 4WD four door, with no rear air.

The Problem: warm air coming out of the vents when the AC is on.

Troubleshooting: with the car off and not driven for a couple of hours I hooked up my trusty Harbor Freight special AC gauges and the reading was 0 on the high side (red hose) and 0 on the low side (blue hose).

By the way the hoses will only hook up to the right inlets as they are of different sizes. Also the vertical high pressure nipple (if you will) is physically "higher" than the horizontal low pressure one which is below or "lower" on the hoses on top of the AC compressor.

Normal reading would be around 125 per side with the system equalized after the vehicle has been sitting for about an hour (to be on the safe side)

So I am [ahem] low on AC juice, actually I am completely out, which unless someone "evacuated" my system when I wasn't looking, means there is a leak somewhere.

 

[Gregski]

only me

OK, so why the post? Well on one of my many trips to AutoZone or as a veteran like me gets to call it AZ for short, I noticed this time of year they have their AC displays right in the middle of the store, and what caught my eye was the little R-134a HIGH & LOW SIDE SERVICE PORT REPAIR KIT for $3.99 mind you.

So I bit, hook, line and sinker since I thought my low side schrader valve had a slow leak which I attributed to me topping off the system over the years and pushing it in and out, in and out, maybe some debris got in there, who knows, all I know when I would remove the dust cap there would be a bit of pressure there.

Anyway I replaced the low side valve with a new one, went to replace the high side, and no go. The little silver tool they give you to unscrew the old valve would not fit. So I shined my trusty flashlight into the hole, an sure enough it don't look like the low side at all.

So this kit, even though I specifically asked the AutoZoner who assisted me if it would fit my WHITE NINETY SEVEN CHEVY TAHOE VEE EIGHT FIVE POINT SEVEN LITTER FOUR WHEEL DRIVE FOUR DOOR WITH AC IN THE FRONT ONLY - does not! So don't buy it, don't try it... and yes sure as sh!t it's the high pressure valve that won't hold a 35 PSI vacuum and has a leak.

 

[Gregski]

the right kit

as I type this I think I have found the right replacement valves by Santech/A/C System Valve Core and Cap Kit for $6.99, but could someone educate me on why there are 3 valves

 

[Gregski]

AC Repair DVD

by the way I highly recommend the AutoZone AC Repair DVD with host; Bruce Bonebrake. He demos everything on a Chevy 1500 truck with our 5.7 liter engine in it. It is by far the best $7.99 I have ever spent on any AC repair.

There is a lot of specific information, and I have watched it at least three times. The first time I just watched in awe as he tears down our system and explains it part by part. The second time I really listened to what is being said and took notes. An the third time I focused on the text messages that pop up on the screen as he talks really fast and it is difficult to absorb all of it at once.

 

[lesterl]

In this episode of the "What a Nightmare" series, The Greg tackles the air conditioning system on his beloved 1997 Chevy Tahoe 4WD four door, with no rear air.

The Problem: warm air coming out of the vents when the AC is on.

Troubleshooting: with the car off and not driven for a couple of hours I hooked up my trusty Harbor Freight special AC gauges and the reading was 0 on the high side (red hose) and 0 on the low side (blue hose).

By the way the hoses will only hook up to the right inlets as they are of different sizes. Also the vertical high pressure nipple (if you will) is physically "higher" than the horizontal low pressure one which is below or "lower" on the hoses on top of the AC compressor.

Normal reading would be around 125 per side with the system equalized after the vehicle has been sitting for about an hour (to be on the safe side)

So I am [ahem] low on AC juice, actually I am completely out, which unless someone "evacuated" my system when I wasn't looking, means there is a leak somewhere.

If someone evacuated the system, wouldnt it read near -30 (I actually get around -28 and keep it at that for an hour before a recharge with the vac pump running.)

 

[lesterl]

as I type this I think I have found the right replacement valves by Santech/A/C System Valve Core and Cap Kit for $6.99, but could someone educate me on why there are 3 valves

I think this is the kit you want. 3 cores, 1 low side, 1 high side switch, cycling switch, and high side port with the rubber looking valve in it.....

I have been thru both kits, and they are pretty cheap to buy.... Good luck.

 

[Gregski]

If someone evacuated the system, wouldnt it read near -30

correct, good point

 

[lesterl]

My 'hoe had sat in a field for 6 years before I got 'er, I evacuated the system for 90 min and recharged, been running cold ever since......