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rebuild my A/C on my S3 turbo

1736 Views 11 Replies 7 Participants Last post by  mieczkow
I have just bought a 1983 esprit S3 turbo. The A/C is out of order. The compressor doesn t work at all and there are leaks of gas from everyparts. I would like to rebuild it completly. It used to work with r12 gas which is no longer available. Is it possible as i m going to change every parts to rebuild it for the r134 gas? Will it work propertly?
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An a/c system is quite a simple system...all it has in it is a pump (compressor), a condenser (in front of the car), an evaporator (in your HVAC system by the heater core), and an expansion valve (in front of the evaporator) to make it all work. There is a dryer to leach out ("filter" out) the moisture inside your system so it won't ice up. The fluid you pump through your system only gives you the efficiency of the system. R12 is much more efficient. It will cool, just not as much. To make 134 work as well as R12, you'll need larger evaporator and condenser.
From the experience with others who have converted to R134, you may not be satisfied with the cooling of that refrigerant in the Esprit.

Several have gone back to R12 if they can find it.

Others have used refrigerant blends such as Freeze12 (don't know if that is available in France, ask around at restoration shops with a lot of older high-end cars).

WELCOME, BTW, what year is your Esprit? :up:
Thanks a lot for these explications. So i need first to find a compressor that works with old R12 gas.
Thanks a lot for these explications. So i need first to find a compressor that works with old R12 gas.
The compressor is a rather common Sanden 508. There are versions of the 508 for both R12 and R134.


Actually, none of the A/C components are really exotic. Most pieces were used in other cars and are readily cross referenced.

A good A/C shop could probably make you new hoses as well (R134 uses a more robust barrier-type hose), if you wanted to go really crazy replacing EVERYTHING.
I have just bought a 1983 esprit S3 turbo. The A/C is out of order. The compressor doesn t work at all and there are leaks of gas from everyparts. I would like to rebuild it completly. It used to work with r12 gas which is no longer available. Is it possible as i m going to change every parts to rebuild it for the r134 gas? Will it work propertly?
My 88 is an R12 system that was minimally converted to R134 - not everything was swapped out and yes, old R12 hoses supposedly allow the R134 to permeate slowly out. It works 'good enough' once I ignored the 2.4 lbs calculated R134 amount (it was too high a pressure, ventilating to atmosphere twice). Use 2 cans (24 oz) and it seems OK. Use at your own risk - every car is 'special'.

The tradeoff of staying with R12 is this: if your system is leaking, you can still buy R12 through a licensed AC company,but it's like $90/lbs (vs. R134 @ $15/ 12 ozs). Slow leaks with R134 are cost-wise more manageable, but with existing R12, it's going to hurt.

Also, have your compressor double-checked - my compressor wasn't 'working' because a loose wire prevented from running.
How can i check my compressor? I mean it s impossible to refill the system with gaz because there leaks from everywhere.
If i have to change the compressor is it possible to do the job without taking the engine out of the car?
And just remember that even a system in perfect working order doesn't work that well compared to newer vehicles.
R-12 availability

I have just bought a 1983 esprit S3 turbo. The A/C is out of order. The compressor doesn t work at all and there are leaks of gas from everyparts. I would like to rebuild it completly. It used to work with r12 gas which is no longer available. Is it possible as i m going to change every parts to rebuild it for the r134 gas? Will it work propertly?
Don't change from R-12! Your AC system was not designed for 134! Don't use any R12 substitutes (like "Freeze"), just GENUINE R12
R12 is plenty available on eBayin US, just expensive.
R12 is readily available in the U.S. - what was prohibited was the manufacture of R12 so there is an existing stock which is legal to use.

When I bought my car it had been converted to R134 and it was almost useless. The AC shop immediately recommended going back to R12 which I did and the AC is just fine - and I live in Florida. Definitely stay with R12 if at all possible in France.

Leaks can be detected with dyes or sniffers or both. If it is leaking "everywhere" just trash the old components and build a new system from scratch. As several have mentioned there is nothing particularly exotic about the Lotus AC. You can probably salvage some parts (condenser, evaporator, etc.) and just replace all the hoses, drier, compressor, etc. A properly functioning AC system with R12 will cool the Esprit just fine. And a properly installed system will NOT leak. I have owned vehicles which are over ten years old and have never required any servicing. A new system with new connectors, new compressor, etc. will not leak so don't worry so much about the cost of R12. If you can afford an Esprit you can afford to pay a few more bucks to get the AC right - in the long run the cost is minimal when extended over time.

And unless you are really experienced and have all the proper gauges, vacuum pumps, etc. I really recommend you have a professional re-do your system.
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Thanks Tom. I totally agree with you ; i want to rebuild it perfectly for the next 30 years. As i have already rebuild the heater cause the matrix was leaking i have change the evaporator. I must find now a condenser ; it is obsolete at Lotus but i found in France a compagny which sells a lot of models for the condenser and for hoses.
Echangeur Condenseur - catalogue de pièces détachées pour climatisation, ECOCLIM
But i don't know what it looks like...
Jim Knowles had a condenser custom built here in the states. Perhaps he can provide some info on the dimensions required.
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