A/C Overhaul - MR2 Owners Club Message Board
 2Likes
  • 1 Post By R.O.B.O.
  • 1 Post By Bigbacon
 
LinkBack Thread Tools
post #1 of 12 (permalink) Old April 20th, 2017, 10:01 Thread Starter
Registered User
 
Join Date: Dec 2016
Posts: 193
OldTrader Rating: (0)
Garage
A/C Overhaul

I still want to get the A/C working in my '85, since I do drive it every day. I don't even have the belt on the compressor right now because there is no freon in the system and the compressor won't engage.

What do I do to get it working on the new R134a stuff? How much cost am I looking at?
achulz is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old April 20th, 2017, 10:24
Lifetime Gold
 
Join Date: Jan 2007
Location: Ithaca, NY
Age: 64
Posts: 10,771
OldTrader Rating: (3)
First you need to find if there are leaks in the system, and fix them. You may find that the long tubes that run through the tunnel are perforated, and they are not so easy to find anymore. I suggest that you deal with this first, because there is no point in going ahead with the refrigerant conversion until you can get a sealed system.
rmeller is offline  
post #3 of 12 (permalink) Old April 20th, 2017, 11:24 Thread Starter
Registered User
 
Join Date: Dec 2016
Posts: 193
OldTrader Rating: (0)
Garage
Quote:
Originally Posted by rmeller View Post
First you need to find if there are leaks in the system, and fix them. You may find that the long tubes that run through the tunnel are perforated, and they are not so easy to find anymore. I suggest that you deal with this first, because there is no point in going ahead with the refrigerant conversion until you can get a sealed system.
I have some doubt that they are perforated, since the rest of my car is pretty much rust free. Though I know the freon is quite corrosive so I'll have a look this weekend. After I make sure the system is sealed, should I just get the new R134a stuff along with whatever oil it needs (and some R12 to R134a adapter fittings)? I know the R12 oil is not compatible with R134a, but I found some stuff online that will apparently allow the conversion?
achulz is offline  
 
post #4 of 12 (permalink) Old April 20th, 2017, 14:03
Registered User
 
Join Date: Jan 2011
Posts: 1,348
OldTrader Rating: (12)
Like rmellet said first thing is to make sure it's sealed up.

There is a lot of line in the mr2 ac system.
Generally in the ac field we use nitrogen to pressure test the system to identify leaks.

There are several ways to find leaks like the soap bubble method or just listening for the "hiss". You can also add a bit of refrigerant in with the nitrogen and use a sleak detector. There is also the UV dye that will show up under a special UV light.

This is step one. Identify if the system is leaking and fix it.

The line set in the tunnel is aluminum and in a foam jacket so it shouldn't be that susceptible to corrosion but it is possible.

The schrader valves in the service ports should be checked they can get old and leak.

I have seen more than one automotive ac compressor leak due to the compressor shaft seal being old or worn into the compressor shaft. If that's the case it is easier to replace the compressor than to repair it. They are a pain to service and seldom does the repair work.

The r134 conversion is fairly straightforward I have done a few write ups in the past concerning the procedure, but in order to do this type of work you really need to have a few HVAC specific tools such as a gauge manifold, vacuum pump and access to refrigerant and nitrogen.

It's do-able but may be one of those jobs you want to outsource to a local garage
escargo likes this.
R.O.B.O. is offline  
post #5 of 12 (permalink) Old April 20th, 2017, 15:56
Lifetime Gold
 
Join Date: Jan 2007
Location: Ithaca, NY
Age: 64
Posts: 10,771
OldTrader Rating: (3)
Quote:
Originally Posted by achulz View Post
I have some doubt that they are perforated, since the rest of my car is pretty much rust free.
The tubes are aluminum, and have their own modes of corrosion.

You can pretty much assume that the system leaks, though. Otherwise, you would still have refrigerant in the system.
rmeller is offline  
post #6 of 12 (permalink) Old April 20th, 2017, 22:14
Registered User
 
Join Date: Oct 2008
Location: East Bay , SF Bay Area
Posts: 2,089
OldTrader Rating: (9)
I have brought back A/C in a couple of 80's cars, and it was an ordeal with both of them. I love the Craigs list big lie "A/C just needs a charge" nonsense. you are dealing with a lot of components that need to be all clean and functioning and don't like sitting for ages in an uncharged unused system,. --high pressure switches, low pressure switches, the evaporator, various sensors, the condenser, the compressor itself, receiver drier, tons of O rings etc etc., Just know what you are possibly in for a lot of work, and you may find out why so few 80's cars have working A/C at this point in the process.
andyS is offline  
post #7 of 12 (permalink) Old April 20th, 2017, 22:26 Thread Starter
Registered User
 
Join Date: Dec 2016
Posts: 193
OldTrader Rating: (0)
Garage
Quote:
Originally Posted by andyS View Post
I have brought back A/C in a couple of 80's cars, and it was an ordeal with both of them. I love the Craigs list big lie "A/C just needs a charge" nonsense. you are dealing with a lot of components that need to be all clean and functioning and don't like sitting for ages in an uncharged unused system,. --high pressure switches, low pressure switches, the evaporator, various sensors, the condenser, the compressor itself, receiver drier, tons of O rings etc etc., Just know what you are possibly in for a lot of work, and you may find out why so few 80's cars have working A/C at this point in the process.
Is there any way I can cannibalize a working A/C system out of another car? Or do those long aluminum condensor pipes make that a no-go?
achulz is offline  
post #8 of 12 (permalink) Old April 21st, 2017, 08:07
Lifetime Gold
 
Join Date: Jan 2007
Location: Ithaca, NY
Age: 64
Posts: 10,771
OldTrader Rating: (3)
Yes, you can, but we are warning you that it is not so simple. I tried for years to find a set of AC tubes for one of my cars, and eventually gave up. One problem is what whenever I worked out a deal with a member who was breaking down his car, he would mysteriously disappear.

I sold an 86 with working AC to Markie last summer, so I know that they exist somewhere.
rmeller is offline  
post #9 of 12 (permalink) Old April 21st, 2017, 11:09
Registered User
 
Join Date: Jan 2011
Posts: 1,348
OldTrader Rating: (12)
Rather than trying to source 30 year old lines from a doner car you could just buy some aluminum line set and hand bend new ones if you needed to.

If that was your plan if attack however if would be easier and smarter to use copper lines, they are easier to find in various sizes, less prone to corrosion and it's way easier to solder connections on copper vs aluminum
This is why all the line sets in commercial and residential ac systems are made from copper. It is more expensive though.

There is one common point in this thread: this is not easy work and if you do decide to tackle this expect to be working on it for a while and replacing many various items.
R.O.B.O. is offline  
post #10 of 12 (permalink) Old April 21st, 2017, 19:20
Registered User
 
Bigbacon's Avatar
 
Join Date: Jun 2010
Location: Capon Bridge WV
Age: 35
Posts: 3,947
OldTrader Rating: (11)
pay to have someone do it. they have the tool to figure out what is good and what isn't. It will cost you though. I wish I still had the reciept from my 88 that PO left. I believe he spent like 800-900 dollars to get the AC system fixed up and working again. A lot of stuff was replaced, including the compressor. that was in 2009, luckily it is still working today.

this was from a completely rust free car.
achulz likes this.
Bigbacon is offline  
post #11 of 12 (permalink) Old April 24th, 2017, 08:43 Thread Starter
Registered User
 
Join Date: Dec 2016
Posts: 193
OldTrader Rating: (0)
Garage
Eh, might as well just rip it all out then. I bet I can save maybe 50 or 100 pounds with all that stuff gone. I always have my windows rolled down anyway, listening to that sweet, sweet 16V sing.
achulz is offline  
post #12 of 12 (permalink) Old April 24th, 2017, 09:31
Lifetime Gold
 
Join Date: Jan 2007
Location: Ithaca, NY
Age: 64
Posts: 10,771
OldTrader Rating: (3)
Make sure that you keep the AC controller. That is also the controller for the radiator fans.
rmeller is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the MR2 Owners Club Message Board forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: (0 members)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome