A/C Help

[glenoweth]

Well It looks like i have some problems with the A/C in my car.
When I turn it on it feels like the heater is on burning me up...
even if i just turn on the fan hot air still blows out. Thank god is a vert because i would die....lol

I checked the pressure from the coolant and it hit 150 psi =( the res zone.
On the can it said if it shows 90-200PSI something mechanical was wrong.

before i start tring to fix it I was woundering if you all had some ideas on where to start 1st. The compresser seems to be moving not sure on the compresser's cluch (going out side right now to check this).


If there is something you all think i need to check please try and give me a idea on where to look in the car =) just to make sure i am looking at the right stuff. Thanks.

[gaindian]

Sounds like a vacuum leak.

[glenoweth]

Sounds like a vacuum leak.

Ummm how do i tell if it is or not?

[fast12]

Who needs a/c drop the top and roll down the windows. You should be use to it owning a 2nd gen.shiftin

[glenoweth]

Yeah but the 2ed Gen did not have leather seats ! llol And the family wants teh AC fixed haha. I can live with out it.

[gaindian]

Everybody feel free to correct me if I'm wrong, but mine was hard to find. Vacuum hoses get old and brittle because of the heat. Cracks develop and there goes the vacuum. Don't know of any other way than by inspection. Might be quicker to just replace the hoses. You can buy hose by the foot and cut to fit. Hope this helps.

[A79Classic]

When my 79 was being checked for vac leaks, he attached a vac hand pump.. the same thing that is used for bleeding brakes. He pumped the trigger and it pulled vaccume.. if it didnt hold or leaked out, then the hose or vac module that was being checked was replaced.. Maybe this will help..

[bobdec]

Glen, Sorry for long post...I'm new to this forum, since your sig is a 1995 Z I assume thats the one having the hot air problem. First your 150 lb on the A/C high side is a little low but it shows your A/C compressor and clutch are not the problem. Probably could use a can of 134, but not critical now. A plugged evaporator core would cause no cool air but that should give very high pressure readings and cause compressor over pressure cutoff, way over 150 lbs. See pics" http://shbox.com/1/ac_performance_chart.jpg " for normal pressures. There is a vacuum controlled blend air door in the ventilation system . The door blends the hot heater core air with cooler air (A/C or vent) entering the car. The Hot/Cool dial on the dash controls the vacuum to the door actuator. If stuck open the hot air will overpower the cooler A/C air resulting in constant heat. The source of the HVAC vacuum is a fitting on the pass (left) side of the intake manifold just behind the charcoal canister purge solenoid (CCP) pics" http://shbox.com/ci/ci259.jpg " Put a vac pump on that line going to the dash and make sure it does not leak (aka: cracked vac line). It could also be the hot/cold dial, or bad actuator on the door. Good luck chasing this down... Pictures courtesy of shbox.com site .... Bob D.

[outlaw77LT]

Miller Repair Service is a full service AC shop, and he gives 10% off labor to all Southeast CamaroZ members.

[glenoweth]

Glen, Sorry for long post...I'm new to this forum, since your sig is a 1995 Z I assume thats the one having the hot air problem. First your 150 lb on the A/C high side is a little low but it shows your A/C compressor and clutch are not the problem. Probably could use a can of 134, but not critical now. A plugged evaporator core would cause no cool air but that should give very high pressure readings and cause compressor over pressure cutoff, way over 150 lbs. See pics" http://shbox.com/1/ac_performance_chart.jpg " for normal pressures. There is a vacuum controlled blend air door in the ventilation system . The door blends the hot heater core air with cooler air (A/C or vent) entering the car. The Hot/Cool dial on the dash controls the vacuum to the door actuator. If stuck open the hot air will overpower the cooler A/C air resulting in constant heat. The source of the HVAC vacuum is a fitting on the pass (left) side of the intake manifold just behind the charcoal canister purge solenoid (CCP) pics" http://shbox.com/ci/ci259.jpg " Put a vac pump on that line going to the dash and make sure it does not leak (aka: cracked vac line). It could also be the hot/cold dial, or bad actuator on the door. Good luck chasing this down... Pictures courtesy of shbox.com site .... Bob D.



AWESOME post man very usefull... I will look in to this tomorrow. from what you are saying it does sound like my vacume has a problem...

[bobdec]

Glen, I may have jumped the gun on the blender door operation. Non climate control cars use a mechanical cable from hot/cold dial to control the door. The vacuum line actually goes to a block on the mode switch to control upper/lower/defrost positioning. If I have some time tomorrow I'm going to pull and plug the HVAC vacuum fitting from my manifold and see what the system does w/no vacuum. A question: to verify it's a hot/cold air flow diversion problem when the car (coolant) is cold do the vents blow 45-50 degree air w/AC @ max 7 RPM @ 1000.

[bobdec]

Glen, I was incorrect, on non climate controlled cars the hot/cold blender is controlled by a mechanical cable attached to the dial, not vacuum actuated. Today I warmed up the car, disconnected the HVAC vacuum line from the manifold, it took some time for the residual vacuum to bleed out of the HVAC lines. With no vacuum the circulation reverted to floor/defrost mode w/no flow through the dash vents. However I still could move the hot/cold dial and the air from the floor & defog vent would switch from hot to cooler outside vented temp. Operation of the A/C is not required to check this out. So if you can change air flow from floor to dash to defrost or combination your vacuum system, solenoids and switches s/b ok.

[glenoweth]

well i got back from my cruise lastnight ,and was going to take the camaro to the shop tomorrow to have it looked at. Well when i started the car to drive it around the block some I checked to see if the a/c worked. Ummmm the darn thing started working fine and when i checked the charge of the fluid
it said full normal on teh psi chart.... odd lol I guess I will have to wait till it brakes again to get it fixed Unless someone here know what it could be.

[coprunr]

dude, i have access to a a/c machine. bring it to the shop one day at lunch or after 5:00 and i'll check it out. i'm not hard to find , just come around the back and ask for Jesse. your right down the road from "The All New Landers McLarty" (what a joke they are....)

[glenoweth]

AWESOME ! you rock man !!!! thanks will do :D:D