R134a A/C Receiver Dryer and Pressure Switch Cross Reference

[Dermot]

S4, S4s, GT3 from 1995 on were fitted with R134a freeon filled A/C system.

I have converted my compressor from the old banned R12 to R134a. Looking at the parts manual that calls for a different receiver dryer and high/low pressure switch. I think some of the older absorbents are incompatible with R134a.

Could someone with the later R134a system have a look to see if there are any markings on the receiver dryer and switch. I want to see if they are just generic items and I will see if I can get a cross reference. The drier is in the front right, it is black with a sight glass on the top. The switch is screwed into the drier. Lotus wants about

[gghc87]

Sorry for asking but is there any reason for not using the RS24 drop in gas which replaces the R12. I had this put in on the old system on my HC and its been fine without any other expensive changes to the system

Edited March 21, 2007 by gghc87

[chandrab]

Parker-Hannifin is the world's largest manufacturer of reciever driers. If you go on to their website (http://www.parker.com/), they have a PDF catalog of components and you should be able to match up an S4 reciever drier. You should be able to parker components at any auto store.

For my 91SE (R-12, but now R134) I was looking for a reciever/drier but couldn't come up with an exact replacement. Parker had an identical unit except the fittings used O-Rings and the Esprit wanted a compression type of fittings. I hear adapters exist but couldn't located any. The only alternative was to change the AC hoses, but that looks to be a bear.

I'd be interested in any interchanges also for the SE.

-Chandra

91SE

[scoule]

R-49 is another drop in replacement for R-12 (in addition to RS24 mentioned above) .. seems a cheaper option that changing components?

[Dermot]

Sadly by compresser was converted when it was being overhauled without me knowing.

Chandra, what receiver drier did you end up putting back in. Did you change the pressure switch. Lotus list three receiver driers (1) SE/early S4, (2) S4/S4s and then (3) GT3/V8 Does anyone know if the pipe fittings are the same ?

I have emailed Dave Massey but he is out today.

Dermot

[gghc87]

Dermot

When I had my system repaired it turned out to only have a leaking pressure switch so this was replaced and all was fine. i spoke to Lotus at the time and having removed the old pressure switch and taken off the adapter. We then attached the old adapter to the new switch. Then refitted it to the compressor. Lotus told me that the pressure switch on my car was not a seperate listed item so the air con company managed to find a switch in there stores that matched the old switch for size and pressure. From memory only one pressure was shown on the old switch but i will try to find the old invoice and see if it says the value.

(THE NEW SWITCH WITH THE REUSED BRASS CONNECTOR)

found this photo of the new switch I took at the time

edit .... not sure any of this is of any use at all as on my system on the HC the pressure switch was located on the air compressor not the receiver..... C

Edited March 21, 2007 by gghc87

[chandrab]

Dermot, the conversion was done by a P.O., but it looks like all the R-12 components stayed the same. My friend who is a MB/BMW mechanic has done many conversions on those cars and typically there is no problem once you change out the oils+R12.

I believe the S4/GT3/V8 use a O-Ring fitting R/D and the SE uses a compression fitting R/D. If so, you you are in luck as the O-Ring types are easy to find. I was just told today by JAE (Lotus parts supplier in CA) that the parker units have conversions fittings for both types. It should be an easy matchup from the Parker catalog from what I remember.

I ended up putting a R-12 Lotus R/D that I got off Ebay. Seems to work OK.

There are people on the US list that have replaced their compressors with the Sanden 508 R-134 units as replacements if that helps. There is an A/C shop in TX that is very helpful when it comes to AC parts for the Lotus. I'm sure someone on the US Lotus Esprit list could help.

-Chandra

Sadly by compresser was converted when it was being overhauled without me knowing.

Chandra, what receiver drier did you end up putting back in. Did you change the pressure switch. Lotus list three receiver driers (1) SE/early S4, (2) S4/S4s and then (3) GT3/V8 Does anyone know if the pipe fittings are the same ?

I have emailed Dave Massey but he is out today.

Dermot

[Artie]

Dermot, the conversion was done by a P.O., but it looks like all the R-12 components stayed the same. My friend who is a MB/BMW mechanic has done many conversions on those cars and typically there is no problem once you change out the oils+R12.

I believe the S4/GT3/V8 use a O-Ring fitting R/D and the SE uses a compression fitting R/D. If so, you you are in luck as the O-Ring types are easy to find. I was just told today by JAE (Lotus parts supplier in CA) that the parker units have conversions fittings for both types. It should be an easy matchup from the Parker catalog from what I remember.

I ended up putting a R-12 Lotus R/D that I got off Ebay. Seems to work OK.

There are people on the US list that have replaced their compressors with the Sanden 508 R-134 units as replacements if that helps. There is an A/C shop in TX that is very helpful when it comes to AC parts for the Lotus. I'm sure someone on the US Lotus Esprit list could help.

-Chandra

I just flushed the system and used an Interdynamics R134a conversion kit 19 months ago. The freon is cool and the A/C system cools well. Not as efficient as my more modern cars but I understand the system wasn't that efficient to begin with.

Artie

[igreenrover]

Guys, did we ever find out if the AC driers listed are interchangeable? I.e. Can I just drop in a later drier into my SE (?) or are the pipe fittings different? I need to convert from R12 and I want to replace my existing one.

Or, if possilbe is there a unit I can source that will do the job?

Gareth

S4, S4s, GT3 from 1995 on were fitted with R134a freeon filled A/C system.

I have converted my compressor from the old banned R12 to R134a. Looking at the parts manual that calls for a different receiver dryer and high/low pressure switch. I think some of the older absorbents are incompatible with R134a.

Could someone with the later R134a system have a look to see if there are any markings on the receiver dryer and switch. I want to see if they are just generic items and I will see if I can get a cross reference. The drier is in the front right, it is black with a sight glass on the top. The switch is screwed into the drier. Lotus wants about

[rene1993earlys4turbo]

A air conditioning system is a closed loop Refrigerant those not live the loop if there are no scape if you have a leak in the system and you see bobbles in the glass in top of your dryer you are bringing in air from outside into your system once air is inside it contaminates the refrigerant when that happens your superheat gets efected dont put more refrigerant into the system becouse you can destroy the valves inside your compressor also water form the air that now is inside with your refrigerant will oxided the alumminun and cooper in the system. The best thing to do is to evacuated the system change the dryer because now you have the dryer with slush and contaminants lots of mechanics that learn A/C in class they dont have the minimun idea how superheat works fixt the leak retofit the R12 Refrigerant vacumm the system to "0" and start all over charge system acording to the pressure of the manufactory recuarament do not attent this if you dont know what you are doing please becouse the system my explode in your face or destroy the compressor. GOOD TOOLING

[claimchaser]

You can also buy Freeze 12 available on e-bay (like everything else) it's also a direct replacement for R-12 and requires no mod's or license to purchase (like R-12)

Good Luck!