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All

I drove the wife's 1998 Z28 convertible this afternoon and the AC isn't quite up to par. The air blowing out the registers is cool but not as cool as my truck. AC probably needs recharging but if it needs recharging does that mean there is a leak?

I live in Rockwall - anybody with any AC experience live out this way and want to lend a hand?

Thanks
Stacy

whitehooptie

iTrader: (2)

Just for starters, look in front of the condensor under that black plastic piece. You'd be suprised at what you would find in there. Plastic bags mysteriously work their way in there, in front of and between the radiator and condensor.

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I checked that already and it is clear....

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Okay so I am going to tackle this one on my own. I went to Harbor Freight and bought a R134a AC Manifold Gauge set for $29.99. It is on sale for $49.99 but their website has it at $29.99 AC Manifold Gauge Set - Harbor Freight so they matched the price on the web!

I then went to Pep Boys and bought 2 12 oz cans of DuPont Suva R134a refridgerant as well as a can of Supercool R134a Oil Charge + U/V Dye which is 4 oz as well as a can tap dispenser (to hook the can to the Harbor Freight AC Manifold Gauges). I also bought one of those AC Thermometers. I figure I would add the Oil Charge/Dye and then add one can of the DuPont R134a.


I did not buy any of that R134a with leak seal or anything else because I have heard others with more experience than I refer to them as "DEATH CANS" - I don't need anymore headaches with this AC system. I guess the question I have is will it hurt anything to add more oil to the system by using the Supercool Oil Charge + UV Dye? I figured that if it had a leak, I would want to add back some oil (just in case) as well as the dye to find the leak.

Does anyone know the static pressure specification for the AC system when it is not running? Does anyone know the high and low side readings that should be posted with the car and ac running?

Thanks
Stacy

LoudGM

iTrader: (12)

High and low side Pressures will depend on temp out side, how clean both coils are, temp hitting the evap coil, ect... Best way to recharge would be to pull it all out, pull a vacum and recharge it with factory wieght specs.

LoudGM

iTrader: (12)

PS. I'm in mesquite if you need help with vacum, and I also have 134a.

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Thanks LongGM - I am just across the bridge/lake so I may take you up on that offer especially if I have to replace some parts and vacuum down the system! For the meantime, I decided to add some R134a and see what happens.

Outside Temp: 104 degrees
Humidity: 60%

Based on this chart that I got on-line AC Performance Chart, it says if the temp is between 100 and 110 with humidity higher than 20% then I should have the following readings:
Here are the initial readings without adding anything:It appears that there are definitely some issues, so I added the 4 oz Super cool (2 oz of lube and 2 oz of R134 plus green dye) and got the following readings:Better but not exactly where it needs to be based on the numbers from the chart, so I added some DuPont R134a. I probably added 10 oz because there was still some in the can but the numbers got considerably better:Static Pressure remained at the 90 psi both Hi and Lo when I checked it again after shutting everything off.

Obviously the air is WAAAAAAAaaay cooler coming out of the registers and there is noticeably more condensation on the lines and the top of the dryer. So I guess we'll see what happens. I will keep checking the register temp by leaving the thermometer in there and will check for the green dye especially around the compressor since I have read that the seals can go bad on these.

So now for the really stupid question - where is the f'ing compressor on this beast? I assume it is underneath since I can't readily see it from the top especially with all this plastic shrouding on the intake - I am use to old muscle cars and IF they had AC, the compressor was a big monster that was readily found.

Thanks....

whitehooptie

iTrader: (2)

Bottom passengerside

rsscoggins

Thanks, that's what I figured. I need to get under there and see if I see any of the dye that may have leaked out.

cooter brown

iTrader: (1)

Thanks for posting up this thread - I'm fixin to have to do the same thing (or close to it) to mine. Seems that the compressor to condensor line 'moved' somehow downward and started rubbing on the sway bar. It was about 98 outside, I'm cruising along and the A/C had the car nice-n-cool when all of a sudden, nothing but hot air starting coming out. Found the hole in the metal part of the hose right on top of the sway bar - new hose = 110.000!!!!!

00pooterSS

iTrader: (40)

The 134 that has the dye should be plenty of oil for just a recharge, the system only holds about 8oz, you dont want to add an additional 50% of the total oil charge on just a top off. In most cases you dont add oil unless its been flushed. I would take that super cool stuff back, and you did good by not getting the leak sealer etc. Stick with straight freon or freon with dye only. Dye is oil with UV reactive dye in it.

Edit: Nevermind just noticed you already added it, if you have too much oil it won't cool as much as its capable of cooling but will be ok.