Gene J Posted May 15, 2008 Share Posted May 15, 2008 My A/C has no leaks and the compressor works fine. But the shop said the evaporator is bad and gave me a VERY high repair estimate. Just how hard is it to replace? Quote Link to comment Share on other sites More sharing options...
lmdew Posted May 15, 2008 Share Posted May 15, 2008 The dash has to come out. Not to bad. What year? I may have one for you. If you pull one out from a yard, you will then know how to do it on y our car. Did the shop evacuate the system for you? R12 or R134? If you have never done this job, plan on a full day. Quote Link to comment Share on other sites More sharing options...
EVOthis Posted May 15, 2008 Share Posted May 15, 2008 if its just the evaporator and not the heater core.....the dash may NOT have to comeout......what kind of car is it? what year? what engine?.....there was a thread not to long ago about someone who did it on a forester and the dash did NOT have to come out......take a look at the related threads down at the bottom of the page..... Quote Link to comment Share on other sites More sharing options...
Gene J Posted May 15, 2008 Author Share Posted May 15, 2008 It is a 98 Legacy GT wagon with the beloved 2.5 liter. Quote Link to comment Share on other sites More sharing options...
EVOthis Posted May 15, 2008 Share Posted May 15, 2008 yeah the post i read a few weeks ago was about i think an 01 or 03 forester and he said he didnt have to remove the dash......as long as the AC system is recovered/discharged by the shop i dont believe its that hard of a job.....i was digging around in mine the other day in my 96 legacy because my water drain was clogged....according to the haynes manual you can get the evaporator out without removing the dash.....its right behind the glove box (at least it is on mine)...if you do happen to tackle the job yourself make sure you install a new reciever/drier..... Quote Link to comment Share on other sites More sharing options...
kamrows Posted May 15, 2008 Share Posted May 15, 2008 I don't know about the 98 Legacy, but if it's anything like my 2003 Forester, it doesn't require pulling the dash. Do a little research and find out how many years they made the same evaporator. I bought mine used and I wouldn't advocate that for your situation (98 model) unless you can get one in good condition. Here is my step by step instructions for what I did: 1. Evacuate R134A coolant (if the evaporator has a leak it might already be evacuated). 2. Remove glove box. 3 Remove heater blower assembly (5-6 screws and or nuts). 4. Disconnect plumbing at firewall (under hood) 5. Remove evaporator cover (will be on right hand side where the blower duct comes in). 6. Slide out old evaporator and replace with new (add a couple onces of appropriate PAG oil to new evaporator). 7. Replace all o-rings with new wherever connections where opened. 8. Replace receiver/drier with new. 9. Pull vacuum on system and look for leaks before recharging with appropriate R134A refrigerant. If you are mechanically inclined you can probably do the job in 3-4 hours maybe less depending on problems encountered. Good luck! Look here first and educate yourself before starting: http://www.autoacforum.com/ http://www.aircondition.com/tech/ Quote Link to comment Share on other sites More sharing options...
kamrows Posted May 15, 2008 Share Posted May 15, 2008 I just re-read your post and you said your mechanic told you there are no leaks but he wants to replace your evaporator, why? I'm just curious, how did he come to that conclusion? Quote Link to comment Share on other sites More sharing options...
Gene J Posted May 15, 2008 Author Share Posted May 15, 2008 I just re-read your post and you said your mechanic told you there are no leaks but he wants to replace your evaporator, why? I'm just curious, how did he come to that conclusion? He said the pressure was the same all the way through the system. Quote Link to comment Share on other sites More sharing options...
nipper Posted May 15, 2008 Share Posted May 15, 2008 Then its not leaking, its the valve thats bad (and forgive me im drawing a blank on it). The valve is stuck wide open. Without that valve you valve (eureka, expansion valve) the coolnat wont change state and you wont have AC. nipper Quote Link to comment Share on other sites More sharing options...
kamrows Posted May 15, 2008 Share Posted May 15, 2008 He said the pressure was the same all the way through the system. Was that the static pressure? If so, that is normal. When he said it was the same, was the engine running or was he just measuring the static pressure of it with the compressor off? When an A/C system is off, the low pressure side and high pressure side will reach equal pressure and that is what the A/C people refer to as "static pressure". If on the other hand, they are the same when the compressor kicks on, that can be a number of things. What was the pressure low or high? I would have your shop explain to you how the pressure being the same means your evaporator is the problem. It might very well be but have them tell you more... Here is how I determined mine was bad: 0-PSI on low side and compressor not running. Added one 12 oz can of R134A refrigerant with UV dye. Compressor ran intermittently until it didn't cool anymore. With UV light, I could see dye dripping out of condensation tube on firewall after running A/C for a while. No leaks anywhere else. My evaporator leak was pretty severe and there weren't any other symptoms so it was fairly easy to diagnose. Once I pulled the evaporator, it was pretty easy to explain why it leaked (full of leaves, sand & debris which, is usually what causes corrosion). Most modern A/C shops have electronic leak detectors and maybe that is what they used in your case. Now it is conceivable you have the same problem I had but I would try and get more info from your shop before tearing into your car and or do some more research on those links I posted earlier. Remember, knowledge is power! Quote Link to comment Share on other sites More sharing options...
Gene J Posted May 16, 2008 Author Share Posted May 16, 2008 Does that valve turn on and off somehow or is it fixed in place? I know the A/C control needs to be taken off and cleaned or replaced. The buttons seldom stay where I want them. Pepsi syndrome.... Quote Link to comment Share on other sites More sharing options...
nipper Posted May 16, 2008 Share Posted May 16, 2008 http://www.wisegeek.com/how-does-air-conditioning-work.htm Best explination i can find. i always assume the basics, but the mechainc did have the car running and the ac compressor engaged when he checked the system? nipper Quote Link to comment Share on other sites More sharing options...
uniberp Posted May 16, 2008 Share Posted May 16, 2008 Then its not leaking, its the valve thats bad (and forgive me im drawing a blank on it). The valve is stuck wide open. Without that valve you valve (eureka, expansion valve) the coolnat wont change state and you wont have AC. nipper Expansion valve. It's in the case right alongside the evaporator coil. The entire case can be pretty easily lifted out of the dash with the glovebox cover removed. Be sure to lubricate the (green,(i forge the compound) new) orings with compressor oil when reinstalling. Quote Link to comment Share on other sites More sharing options...
samneric Posted May 1, 2011 Share Posted May 1, 2011 (edited) Was that the static pressure? If so, that is normal. When he said it was the same, was the engine running or was he just measuring the static pressure of it with the compressor off? When an A/C system is off, the low pressure side and high pressure side will reach equal pressure and that is what the A/C people refer to as "static pressure". If on the other hand, they are the same when the compressor kicks on, that can be a number of things. What was the pressure low or high? I would have your shop explain to you how the pressure being the same means your evaporator is the problem. It might very well be but have them tell you more... Here is how I determined mine was bad: 0-PSI on low side and compressor not running. Added one 12 oz can of R134A refrigerant with UV dye. Compressor ran intermittently until it didn't cool anymore. With UV light, I could see dye dripping out of condensation tube on firewall after running A/C for a while. No leaks anywhere else. My evaporator leak was pretty severe and there weren't any other symptoms so it was fairly easy to diagnose. Once I pulled the evaporator, it was pretty easy to explain why it leaked (full of leaves, sand & debris which, is usually what causes corrosion). Most modern A/C shops have electronic leak detectors and maybe that is what they used in your case. Now it is conceivable you have the same problem I had but I would try and get more info from your shop before tearing into your car and or do some more research on those links I posted earlier. Remember, knowledge is power! Excellent thread and suggestions. I have a '98 OBW 215k miles that was not blowing 100% cool when I bought it - Last August. The guy who sold it said it wasn't so it is a known issue. It got worse over winter and blows warm now. I put a can on freon in to no affect. I put my gauges on it yest - 100 psi on low and high. With the compressor hub spinning and without it spinning (ac on or off). I just ordered a new AC Compressor kit from napa inc the drier and expansion valve. Could it also be the evap leaking if I pull it out covered in leaves and debris? It definately has charge because it let out a hiss if I opened the gauge valve for a second. What are the number of causes for static pressure with the A/C on again???? Expansion valve stuck open? Comp not working? Steve Edited May 1, 2011 by samneric Quote Link to comment Share on other sites More sharing options...
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