A/C Evaporator died..
Thread Starter
Le Mans Master
Joined: Sep 2001
Posts: 7,928
Likes: 1
From: More cowbell...
St. Jude Donor '04
A/C Evaporator died..
Well, last year when I was replacing my opti, as I was lifting the AC stuff off to the side a bit, I killed my evaporator (hissing, and white stuff was coming out of the black foam that goes into the evaporator housing).
So, now I need to 1) replace the evaporator, 2) convert to 134a.
Replacing the evaporator doesn't look too bad, but I have no idea what I need to do to convert to 134a. What all needs to be replaced? O-rings, and then pull a vacuum, then charge with the 134a? Any tips?
So, now I need to 1) replace the evaporator, 2) convert to 134a.
Replacing the evaporator doesn't look too bad, but I have no idea what I need to do to convert to 134a. What all needs to be replaced? O-rings, and then pull a vacuum, then charge with the 134a? Any tips?
Safety Car
Joined: Sep 2002
Posts: 4,030
Likes: 6
From: Maryland
Originally Posted by MarkLT1
Well, last year when I was replacing my opti, as I was lifting the AC stuff off to the side a bit, I killed my evaporator (hissing, and white stuff was coming out of the black foam that goes into the evaporator housing).
So, now I need to 1) replace the evaporator, 2) convert to 134a.
Replacing the evaporator doesn't look too bad, but I have no idea what I need to do to convert to 134a. What all needs to be replaced? O-rings, and then pull a vacuum, then charge with the 134a? Any tips?
So, now I need to 1) replace the evaporator, 2) convert to 134a.
Replacing the evaporator doesn't look too bad, but I have no idea what I need to do to convert to 134a. What all needs to be replaced? O-rings, and then pull a vacuum, then charge with the 134a? Any tips?
Tips: keep your R12, as long as it is not leaking from somwhere you can't find. Costs too much to switch and it isn't any cooler.
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
http://www.epatest.com
Take test 609
It's done on line and is an open book test.
Once you have been certified, you can purchase R12 from any supplier or on E-bay. You only need about 2.5 lbs for the Vette.
Take test 609
It's done on line and is an open book test.
Once you have been certified, you can purchase R12 from any supplier or on E-bay. You only need about 2.5 lbs for the Vette.
Safety Car
Joined: Oct 2000
Posts: 4,236
Likes: 355
From: Albuquerque, NM
Try to keep the R12 if you can. R134a is 10% less efficient. Call around to shops that work on automotive AC. Usually you can still find R12, although it is expensive. The good thing is it's not something you'll need to replace frequently.
One tip when replacing the evaporator core: be EXTREMELY careful when you remove the large black plastic evaporator core housing not to damage the heater core hose fittings. It doesn't take much sideways pressure to break a solder joint where the brass hose fittings join to the body of the heater core. I replaced my evaporator and was a little too harsh getting that housing out of the car. As a result, I broke a solder joint on the heater core and caused a heater core leak. Then after replacing the evaporator core I had the pleasure of doing the heater core. Trust me, you want to avoid having to do the heater core!
Also, if you haven't replaced spark plugs in a while this is a wonderful time do to it, as the evaporator core housing is out of the way and that dreaded passenger side rear plug is perfectly accessible. The fuel filter and passenger side O2 sensor are also a little more accessible.
One tip when replacing the evaporator core: be EXTREMELY careful when you remove the large black plastic evaporator core housing not to damage the heater core hose fittings. It doesn't take much sideways pressure to break a solder joint where the brass hose fittings join to the body of the heater core. I replaced my evaporator and was a little too harsh getting that housing out of the car. As a result, I broke a solder joint on the heater core and caused a heater core leak. Then after replacing the evaporator core I had the pleasure of doing the heater core. Trust me, you want to avoid having to do the heater core!
Also, if you haven't replaced spark plugs in a while this is a wonderful time do to it, as the evaporator core housing is out of the way and that dreaded passenger side rear plug is perfectly accessible. The fuel filter and passenger side O2 sensor are also a little more accessible.
Thread Starter
Le Mans Master
Joined: Sep 2001
Posts: 7,928
Likes: 1
From: More cowbell...
St. Jude Donor '04
Ok, so I got the cert, so I can now buy R12.
Now I just need to know exactly what I need to do this.
From what I understand (since the system is already drained), the first step after replacing the evaporator, is to pull a vaccum on the system. I have seen ~$20 vacuums online for this- are these the way to go?
Then, it looks like the next step is to hook up a can of R12, and start filling the system, with the engine/AC off. Once I get as much as will go just under the vaccum, I then run the AC at full blast, and fill in the rest of the 2.5lbs of R12. Does this sound about right? Anything else I need to do this job? Any steps I have messed up, or out of order?
-Mark
Now I just need to know exactly what I need to do this.
From what I understand (since the system is already drained), the first step after replacing the evaporator, is to pull a vaccum on the system. I have seen ~$20 vacuums online for this- are these the way to go?
Then, it looks like the next step is to hook up a can of R12, and start filling the system, with the engine/AC off. Once I get as much as will go just under the vaccum, I then run the AC at full blast, and fill in the rest of the 2.5lbs of R12. Does this sound about right? Anything else I need to do this job? Any steps I have messed up, or out of order?
-Mark
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
You should also replace the Accumulator and orfice valve (Expansion Valve). You can use a 3 inch drywall screw to remove the old orfice valve. Autozone sells the orfice valve for around $2.00.
You also need some 525 viscosity mineral oil.
Most stores don't carry it but you can still get it on the Internet.
Add 2 oz of oil to the Accumulator, 2 oz to the Condenser and 2 oz to the Evaporator.
Pull a vacuum on both high and low side for a couple of hours. Shut the pump off. The low pressure gage should show at least 28 inchs of vacuum. Let it sit for a couple of hours. If the reading changes, you have a leak. If no change in the gage reading, you can charge the system.
If you're not sure about the charging procedure, you can replace everything then take it to a AC shop and have them evacuate and charge the system with the R12 that you provide.
You also need some 525 viscosity mineral oil.
Most stores don't carry it but you can still get it on the Internet.
Add 2 oz of oil to the Accumulator, 2 oz to the Condenser and 2 oz to the Evaporator.
Pull a vacuum on both high and low side for a couple of hours. Shut the pump off. The low pressure gage should show at least 28 inchs of vacuum. Let it sit for a couple of hours. If the reading changes, you have a leak. If no change in the gage reading, you can charge the system.
If you're not sure about the charging procedure, you can replace everything then take it to a AC shop and have them evacuate and charge the system with the R12 that you provide.
Last edited by Hooked on Vettes; Mar 22, 2005 at 07:57 PM.
