jdoyle

iTrader: (27)

Techers,

what is the rule of thumb for time between rear end fluid/coolant changes? Once a year?

Do our A/C systems have filters that we can change out without having to recharge the system like the say 2001 xcab silverado? if so, where are they?

this one is the weird one.
i drive from home to school alot and it is a little longer than a 2 hour drive, going about 75 the whole way. my a/c when i leave either place is AWESOME, fan blows very well and the air is very cold and i am very happy. but about an hour into the drive or so, the air will still be cold, but it is not coming out nearly as fast, not fast enough to keep me from sweating. any idea what is causing this and how to fix it? i understand that the compressor gets hot while driving which makes it harder for the compressor to cool the air, but damn. this is not the first time this happens either, once she cools down, she is good to go again with the good fan speed and air temp.

the compressor has very little use on it.

Thanks,
JD

EDIT: let me know if you need any other info.

Luder[PAK9]

Rear end = every 15k miles
Coolant = if you're using dexcool or other extended life = 5yrs/100k miles. Regular green = 2 yr/30k miles.
A/C is completely sealed. No filters that you can change.

Can't help with the a/c problem. Does the fan speed stay constant, or does is blow less strongly after 1 hr as well?

9000th01ss

iTrader: (10)

Sounds like your AC evaporator coil might be icing up. Caused by obstructed airflow, dirty fins on it, low or improper freon charge.
Get a cheap thermometer to put in the vent and see if at any point it blows below 34*

I say this because I've experimented a lot with automotive AC, I worked for a AC company and the truck they gave me had no ac so I put r22 (house freon) in it and it would blow in the 20* range until chunks of ice and fog would start coming out of the vents, then it would stop blowing. The evaporator was icing up because I could shut the compressor off and it would blow cold for another 15 minutes afterward, and when I'd stop it would drip water forever.

That refrigerant you get at the auto parts store that improves ac performance actually has a small amount of r22 in it, thats how it gets it to cool better.

Also in the system I put in my personal truck I put an old style adjustable compressor cut out switch on it so the vent temp gets in the 30's, sometimes it ices up too and does the same thing you're describing.

The most common problem you probably have is low refrigerant, it wouldn't hurt to pull the blower assembly out to be sure it's not full of leaves, etc. I guess it could be your compressor cycling switch too, but the '98 and up F Bodies seem to work off the liquid line so I don't really think that would do it. There is no low side compressor cycling switch on these cars.

jdoyle

iTrader: (27)

thanks for clearing that up. after about an hour, the air is still cold, but its definitely blowing weaker, its like the ac isnt even on.

this might help:
start trip: air blows hard, like a leaf blower to the face. very cold air.
1hr into trip: air still very cold, but its like the leaf blower was replaced by someone blowing thru a straw, so its not getting on me at all.

jdoyle

iTrader: (27)

9000th01ss

I think it could maybe be low refrigerant, not saying you are wrong, cuz you know more than i do. When i got the car the a/c sucked, so i got a new GM compressor (cuz i knew the old one was bad, had it recharged with the dye, and after a while, the dye was very obviously everywhere around the comp) and took it to a reputable place and everything turned out great. i do not drive the car very often, but i make sure that a/c system gets exercised at least like once a week to a week and a half, never letting it sit longer than that, cuz i know the freon can leak out and i do not want that to happen.

could you give me any more info on the blower assembly? dont know where it is and such.

do you think it could be from doing a few "highway bombs" a few times during a 2-2.5 hr trip with the ac on max?

Thanks for the help!

9000th01ss

iTrader: (10)

just a quick reply