A/C leak detection

[WildBillyT]

Any tricks? System seems to hold pressure on the low side with the engine off but loses it when the system is turned on, so I'm guessing a high side leak? It's hard to hear a leak with the fans on and engine running.

[BonzoHansen]

dye

[WildBillyT]

Is that it, or is there a way to hook it up to compressed air and look for a hiss?

[Stevoone]

I've seen other techs use leak detectors. The one we have at the shop is really touchy and I never use it, i'd rather use dye unless its a larger more obvious leak. similar to these (ours is really old) http://www.amazon.com/s/?ie=UTF8&keywords=r134a+leak+detector&tag=googhydr-20&index=aps&hvadid=9398123557&hvpos=1t1&hvexid=&hvnetw=g&hvrand=185628947288401707&hvpone=&hvptwo=&hvqmt=e&ref=pd_sl_5ka58bgawy_e


The main problem I could see with using compressed air would be the moisture you would let into the system. Unless you can vacuum it out for a long period of time you may create more problems.

[BonzoHansen]

Is that it, or is there a way to hook it up to compressed air and look for a hiss?

no. dye or an ac sniffer

[MyFirstZ]

I've never found an a/c sniffer that is accurate.

If you can see all the areas that the high and low pressures line bolt to that will use o-rings to seal you can try spraying windex or some sorta of soapy water to see if it bubbles otherwise dye is the best.

You can also have a cracked evaporater and be leaking in the heater box sometimes you can see dye where the drain tube would leak out to.

[WildBillyT]

Dye it is. Thanks fellas.

[WSex]

what are your running numbers on the low and high?

[sweetbmxrider]

Dye or a sniffer is what I do.

[greenformula92]

Put the Dye is and then use the A/C, go for a ride and really let the A/C run. after your drive look for the dye. Mine is leaking out of the A/C compressor out of every nook in the casing itself. and it is super obvious and easy to see. if its leaking in a tight spot a blacklight might help

[MyFirstZ]

Black light and yellow tinted glasses you get in a kit and it will be clear as day

[1984camaroz28]

Black light and yellow tinted glasses you get in a kit and it will be clear as day

x2 ...

[WildBillyT]

Didn't even get that far. It's the A/C box itself.

[MyFirstZ]

A/c box ?

Talking about the evaporator? Curious

Pictures or anything

[BonzoHansen]

I'm guessing evaporator?

[WildBillyT]

Yeah, that's what I meant.

http://i211.photobucket.com/albums/bb278/SprayedLT1/Engine%20swap%20project/heaterbox-1.jpg

Not my car, and this is hacked up, but the dye/oil is leaking on the heat sheild near the toe pan.

[MyFirstZ]

Glad you found it.

Not sure if that only houses the evaporator or not

Think that is your tev (thermal expansion valve) where the connection is made might also have a connection inside

Just remember follow the leak from the highest point

[WildBillyT]

Didn't know the car had no motor. Little hard to diagnose using dye that way but glad you found it.

No, it has a motor. This pic is not my car, just a good shot of the area.

[MyFirstZ]

Yeah I fixed it and edited haha

Not your car but still a 4th gen like in the picture ?

[WildBillyT]

Yeah I fixed it and edited haha

Not your car but still a 4th gen like in the picture ?

Yes. 1995 Trans Am.

[BonzoHansen]

I might have an evap for you out of a 99

[WildBillyT]

Let me know if you do. I need to check compatabilitiy, too.

[BonzoHansen]

check it I'm 99% sure I still have it

[sweetbmxrider]

Its not that bad to do. I used to have a couple but I think I scrapped them.

[LTb1ow]

I have one from my 95

[MyFirstZ]

Jersey mike has one still in the 2000 ta

[WildBillyT]

Its not that bad to do. I used to have a couple but I think I scrapped them.

Is it an under dash/gotta pull a ton of parts deal or just a PITA in the engine bay?

[LTb1ow]

I am gonna assume the whole HVAC box needs to come out, which means dash coming out etc.

[sweetbmxrider]

Is it an under dash/gotta pull a ton of parts deal or just a PITA in the engine bay?

I am gonna assume the whole HVAC box needs to come out, which means dash coming out etc.

Should just be the top cover on the engine bay portion of the box? Or the whole firewall side of the box if it doesn't separate, I can't remember atm. The heater core and blower motor are inside the car. I may be wrong though as AllData says;

Remove or Disconnect

Discharge refrigerant into a recovery station.
Right-hand instrument panel sound insulator panel.
Heater hoses at heater core.
Instrument panel compartment.
Heater Core.
Air conditioning evaporator temperature sensor.
Temperature control cable at temperature valve case.
Bolts/screws (48) located in engine compartment from temperature valve case (42).
Temperature valve case (42).
Slide case (42) downward to disengage upper case clip.
Remove from under the instrument panel.
Thermostatic expansion valve.
Important

Remove perforated section of heater and air conditioning evaporator module as one piece (it will be reused).
Water can leak onto carpeting when doing this procedure. It is recommended that a mat be placed on passenger side floor.
Using a small hand saw, remove perforated section of heater and air conditioning evaporator module.
Important

This piece of material is required to keep condensate from draining inside vehicle.
Bolts/screws (41) retaining air conditioning evaporator (3).
Air conditioning evaporator (3) from heater and air conditioning module (11).
Slide evaporator (3) to the left, then pull out through the opening enlarged in step 11.
Install or Connect

Transfer condensate screen to new evaporator (3).
Install new evaporator core gasket in same position as original with appropriate adhesive.
Air conditioning evaporator (3) to heater and air conditioning module (11).
Insert evaporator (3) into module (It) through the opening enlarged during removal, slide to the right until fully seated.
Bolts/screws (41) to air conditioning evaporator (3).
Thermostatic expansion valve.
Apply sealer GM P/N 3012078 (do not use epoxy glue) between evaporator (3) and evaporator upper and lower case (44 and 45) just behind thermostatic expansion valve to prevent air entry from the engine compartment into the passenger compartment.
Position perforated section of heater and air conditioning evaporator module and use epoxy glue to adhere it to module. After epoxy dries, use thumb to grade sealant on inside and outside to ensure water-tight seal.
Temperature valve case (42).
Install from under instrument panel.
Slide case (42) upward into position until upper clip engages.
Engage snap on left edge of temperature valve case (42) to distributor case (46).
Bolts/screws (48) to temperature valve case (42).
Temperature control cable at temperature valve case.
Air conditioning evaporator temperature sensor.
Heater core.
Instrument panel compartment.
Heater hoses to heater core.
Right-hand instrument panel sound insulator panel.
Fill radiator and bleed cooling system.
Refrigerant oil into evaporator (3), if necessary.
If installing new evaporator (3), add 89 ml (3 fluid ounces) of polyalkylene glycol (PAG) synthetic refrigerant oil, GM P/N 12345923.
Tighten
Bolts/screws (48) evenly to compress flange seal.

[LTb1ow]

AFAIK, you cannot split the HVAC box in the engine bay, it needs to come through the firewall to be split in two.

[Jersey Mike]

Jersey mike has one still in the 2000 ta

This. Let me know if the other two fall through and it's yours.

[sweetbmxrider]

AFAIK, you cannot split the HVAC box in the engine bay, it needs to come through the firewall to be split in two.

Yeah thinking about it, I think you are right. That makes things worse :lol:

[V]

pulling the dash is easy after you've done a dozen or so

[deadtrend1]

pulling the dash is easy after you've done a dozen or so

Yeup, ive gotten good at it. Hardest part is trying to not crack the dashpad. If you need a hand lemme know.