| Author | Message | ||||
     Alan Dibley Frequent User Username: alsdibley Post Number: 315 Registered: 10-2009 |
Is there any authoritative data on the charge quantities for R134A and lubricant after conversion from R12? I've searched the forum and not found any, am I looking in the right place? There seems to nothing in the Tech library. I've made it work by guessing, but..... Alan D. | ||||
| Brian Vogel Grand Master Username: guyslp Post Number: 3210 Registered: 06-2009 |
Alan, This is generally determined by what the amounts were for the R12 system being converted. I've got some hard data from the SZ era when the refrigerant change took place, but I don't know whether it can be applied backward to the SYs or not. Brian | ||||
| Brian Vogel Grand Master Username: guyslp Post Number: 3211 Registered: 06-2009 |
Alan, In reviewing my archive I see I was mistaken. I have this information for the SY1 era cars and for the SY2 & SZ era cars.
Brian | ||||
| David Gore Moderator Username: david_gore Post Number: 4007 Registered: 04-2003 |
Alan, An alternative more efficient refrigerant replacement to R134a in Australia is available called "HyChill Minus 30" which I used successfully in my Toyota 4Runner 4WD with performance very similar to the original R12 refrigerant. https://hychill.com.au/en/products/minus-30 . | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 316 Registered: 10-2009 |
Hi David, Hycool is not available here, and a few others R12 replacements have become unavailable - unless someone knows better. I've looked for similar R12 replacement stuff available in UK, but there is nothing. Similar gas is available from France at high cost - I don't feel comfortable with relying on a "difficult" source, especially after the import problems introduced by Brexit. Conversion to R134A is a long-term solution, and I hope I need a long-term solution. Alan D. | ||||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 726 Registered: 07-2015 |
Hi , you can use propane for refrigerant ,cheap and works great also much better for the environment. Look on YouTube. Mike | ||||
| David Gore Moderator Username: david_gore Post Number: 4008 Registered: 04-2003 |
Michael, Propane is not a safe alternative refrigerant for R12/R134A in car airconditioning systems for one basic reason; it is a flammable gas and if the car is involved in an incident where the vehicle air conditioning system is compromised and the vehicle catches fire, it is highly probable the Insurer of your vehicle would deny responsibility for settling claims as a consequence of the vehicle being in an unsafe condition as a consequence of using a non-approved flammable refrigerant. The situation becomes worse if someone is seriously injured or killed in an incident of this type. | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 317 Registered: 10-2009 |
Brian, thank you. just what I needed (and a few other folk too, I suspect). Alan D. | ||||
| Mark Aldridge Frequent User Username: mark_aldridge Post Number: 745 Registered: 10-2008 |
Alan, my son has used this successfully in his cars https://www.ebay.co.uk/itm/353596840484?epid=10031188906&hash=item5254039a24:g:RGsAAOSwQZFeTrnL together with their leak stop. However I am not confident with hydrocarbons so I am using RS24. Mark | ||||
| Omar M. Shams Grand Master Username: omar Post Number: 2167 Registered: 04-2009 |
If I can reiterate - please do not use propane as a refrigerant in any car. Read every word that David has written above carefully. There have been many deaths because of this. All would have been avoidable. | ||||
| Robert J. Sprauer Frequent User Username: wraithman Post Number: 700 Registered: 11-2017 |
Compressor oil has to be changed to PAG 150 when converting. The system also has to be solvent flushed and the drier replaced. Ultimately the correct A/C volume of R134a is determined by your manifold gauge readings, but it is usually 80% of what the R12 quantity is. | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 318 Registered: 10-2009 |
Perhaps I should explain that it already has connectors, oil, dryer, O-rings etc. changed and an experimental dose of R134A, and it works. I just want a guide as to how much gas to put in - it's a lot more than a modern system. I will compromise on the pressure because it is a 50 year old car. Even with a few hundred grams it almost cools enough for UK conditions. Alan D. | ||||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 727 Registered: 07-2015 |
Hi hichill minus 40 is R290 is propane. https://hydrocarbons21.com/articles/2439/hychill_minus40-r290_the_solution_to_replace_r22 | ||||
| Brian Vogel Grand Master Username: guyslp Post Number: 3212 Registered: 06-2009 |
I really don't get the push to replace R134a with anything else. The AC in our cars can and does still blow bone-chillingly cold air with a properly charged R134a system. I am with Alan in that if you're going to do conversions on these cars (and you have to as time marches on) using the most commonly available and most likely to continue to be commonly available refrigerant for automotive (and other) purposes. From what I understand even R134a is being phased out sometime in the reasonably foreseeable future for something that's even less potentially environmentally damaging if released into the atmosphere. But I can't remember what that one is called. It's been a couple of years since my last heavy-duty AC refrigerant research. | ||||
| David Gore Moderator Username: david_gore Post Number: 4009 Registered: 04-2003 |
Brian, My experience of a company car fitted with a standard R12 system later recharged with R134a revealed a marked decrease in the effectiveness of the system in our hot summer climate after the conversion. Your climate is such that this problem rarely, if ever, is likely to be noticeable. For this reason, the non-flammable "Hychill" refrigerant was widely used here when recharging R12 systems showing their age. The market for Hychill here now would be almost entirely for classic and collectable vehicles kept and maintained by classic/historic vehicle custodians. . | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 319 Registered: 10-2009 |
The new gas is R1234YF. Who thinks up these names? I suppose it is based on the chemical formula, but can't see how. See more gen on https://refrigeranthq.com/r-1234yf-refrigerant-fact-info-sheet/ It is now mandated for new cars in the EU. https://refrigeranthq.com/r-1234yf-refrigerant-fact-info-sheet/ Alan D. | ||||
| Brian Vogel Grand Master Username: guyslp Post Number: 3213 Registered: 06-2009 |
Alan, And if conversion to such is an option, that's how I'd go. I knew that R134a was being phased out, but if it's that far along in being phased out where you live then it makes sense to get what is, and will likely remain, legal and easy to obtain for a couple of decades, at least. Brian | ||||
| Larry Kavanagh Frequent User Username: shadow_11 Post Number: 784 Registered: 05-2016 |
I'm presuming that the various o-ring seals for use in R134 systems are also suitable for use with R1234YF? | ||||
| Omar M. Shams Grand Master Username: omar Post Number: 2168 Registered: 04-2009 |
Dear Alan, We need to all see the big picture here. You want your air conditioning to work and for it use R134 and for the system not to fail. You are happy for reduced efficiency given your geographical location. This is what I would do - I would evacuate the system to as much a vacuum as I can. If it has enough oil in the system I would simply introduce R134a gas into the system noting the maximum quantity allowed from the notes above. I would introduce half the quantity and work my way up using 200 PSIG as the maximum discharge pressure until it cools adequately to your satisfaction. This method allows the system pressure not to exceed 250 psig (when hot) and the refrigerant quantity to be adequate for your needs. | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 320 Registered: 10-2009 |
Omar, that is almost exactly what I have done. It has 800grams of R134A instead of the quoted 1050 grams, and it reduces the temperature quite enough, I think, for UK conditions - there hasn't been any weather hot enough recently to test it in real life. I removed the Throttling Valve from the circuit as being a PITA and it doesn't really do the job of keeping the cabin temp where it should be without manual intervention. So, because my Citroen CX25GTi has automatic cabin temperature control, I am partway through fitting that feature to the Bentley - it is easier than trying to get the temperature probe in the Throttling Valve mod kit to be attached and wrapped to that inaccessible tube below the expansion valve. More info if and when it works. Taking the cars round to the local R134A shop had all the staff out to see them, either for a demo of "up-and-down" suspension or to gawp at a classy motor. Alan D. PS. Some years ago I accidentally bought an industrial size vacuum pump with metering down to 0-10Torr. It is a monster and lives on a trolley but it has a lot of SUCK in capital letters. The local A/C shop can't match it. | ||||
| Robert J. Sprauer Frequent User Username: wraithman Post Number: 701 Registered: 11-2017 |
Cooling is relative to ambient temp. I large fan should always be placed in front of the condenser to move air like on the hiway when performing A/C work. | ||||
| Omar M. Shams Grand Master Username: omar Post Number: 2169 Registered: 04-2009 |
That's an interesting take Robert. I usually do the opposite. I try to simulate a traffic jam at the height of a summer day with the bonnet closed and do my AC settings under these conditions. This is when you have the most difficult conditions for the AC system. If it cools under these conditions it will always cool. | ||||
| Brian Vogel Grand Master Username: guyslp Post Number: 3214 Registered: 06-2009 |
Omar, I'm with you on this one. When there's a massive ram supply of air being pushed through the AC condenser and radiator that's when both are having "the easiest time of it" for doing what they're supposed to do. I imagine that on the hottest days in Dubai it's entirely possible that the supplemental electric fans could come on to get additional air flow through the condenser when stuck in traffic, after the car is hot, anyway. But in most of the world, from everything I've been told, the supplemental fans never come on in practice. There's actually a current topic about those on rollsroyceforums.com. Brian | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 321 Registered: 10-2009 |
And on the topic of electric fans, I once had a Spirit with one of them. It didn't work and the reason was that the commutator on the 'pancake' motor was completely worn away. It is difficult to see how that could happen considering that they only run occasionally and anyway the wear would stop when the track was nearly gone because the motor would stop working - until one realises that the fans turn all the time the car is moving, the airflow over the blades makes it so. Was this original fitment? Do they wear quickly on all cars with electric fans? Alan D. who has gone off-topic again. | ||||
| Brian Vogel Grand Master Username: guyslp Post Number: 3215 Registered: 06-2009 |
Alan, It's your topic, as the OP. And as far as I'm concerned, once the core question has been answered for any topic, it can go in any direction the participants wish and not be hijacking. The nature of conversations is that they meander. And this one is doing the natural thing, since your initial query has been answered. Brian | ||||
| Mark Aldridge Frequent User Username: mark_aldridge Post Number: 746 Registered: 10-2008 |
Alan, the fan on my Spirit seized, presumably through salt etc. Mark | ||||
| David Gore Moderator Username: david_gore Post Number: 4010 Registered: 04-2003 |
Brian/Alan, The auxiliary condenser fan can rotate of its own accord even when the A/C system is turned off from the normal airflow through the radiator whilst the vehicle is moving. Even though the fan is not powered in this situation, the brushes will still be subject to wear from induced rotation. If the car is being used in a dusty or polluted environment, this wear will be exacerbated.  | ||||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 2466 Registered: 09-2004 |
IMO the use of a pusher brushless fan unit may well help in adverse conditions. On the subject of refills with air con gas the more modern air con machines do the whole change and refill automatically. To check any time use the sight glass. | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 322 Registered: 10-2009 |
My T now has automatic cabin temperature control. Switch to any of the cooling positions on the "Upper" switch and the compressor clutch is cycled to maintain a fixed temperature - I have it set to 21C, colder than that gives a "thermal shock" when leaving the car and hitting the heat. I used a needlessly complex temperature controller, the system needs a simple on/off without PID algorithms or anything fancy. I hid the works in the cavity/glove-box? immediately above the passengers feet and ran the wires through a hole I discovered in the bulkhead in a convenient place - I enlarged it a bit and shrouded the 4 wires in spiral binding. It works OK if the upper and lower heaters are left full on for a few minutes to cook the inside of the car (30C+) and then the Upper is set to cool. The compressor starts and in a minute or two turns off when the cabin temp gets down to 21C. I didn't do any real data collection. Now I need a heat-wave to do a real-life test. Alan D. | ||||
| Larry Kavanagh Frequent User Username: shadow_11 Post Number: 785 Registered: 05-2016 |
Well done Alan. I'm also about to replace my compressor and other components and convert to R134A, I have had all the new parts sitting in a box for more than a year but other more urgent stuff had me sidetracked. Your endeavours have given me the inspiration to start soon. | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 323 Registered: 10-2009 |
I should clarify that part of the reason for going to an automatic cabin temp system came from the decision to dispense with the complicated Throttling Valve and use the temperature controlled switch replacement kit (££££), because: A) It is close to impossible to install the switch with the probe end down behind the hydraulic reservoir (it might be different on other cars), and B) It doesn't control the cabin temp, it is still necessary to switch the cooling on and off manually. I've ordered a simple adjustable temperature switch for a few ££, and will replace the complicated microprocessor-controlled box installed at the moment. The total real cost should be much less than £20(GBP) (say $30) even if you have to buy all the spade and bullet connectors and cable. The most expensive part is a DC-DC sold-state-relay to take the spiky switching load away from the tiddly relay on the controller board. Plus a few hours work, but we all love working on our treasures. Don't we? I have not altered any original wiring, so any future purist can revert to 1970s technology if needed. With hindsight I would not have bought the valve kit and saved a lot of money. Blanking off the valve body is not rocket science. The expensive bit of the kit is the temp-controlled switch. Anyone want it for postage cost. Alan D. | ||||
| Mark Aldridge Frequent User Username: mark_aldridge Post Number: 747 Registered: 10-2008 |
Alan, is your car a Shadow1 or 2 ?The cabin temp control appeals with a Shadow 1 where the aircon is basically a manual fridge . Presumably this could be controlled with a relay and adjustable temp switch. can you give part details and suppliers for the parts you have used. I have already fitted the throttle valve temp kit, but this does not control cabin temp on a Shadow 1. Mark | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 324 Registered: 10-2009 |
Hi Mark, mine is a T not a T2, so the original control is manual, as you say. The controller is any of the units on Ebay (there are other sources) such as HCRM01 (a very basic unit with no indicators but it would work) or W3002, W1209S, W1401 or W3230 and others. They vary in presentation, features and enclosure or lack of it. I've ordered a W3230 to replace the "posh" one I fitted first. To protect the relay output points I use a SSR-40DD (Ebay again) solid state relay. Massive overkill current-wise (40Amps!!!) but it will last forever and I didn't have anything less brutal - I think 25Amp versions are made, maybe less. I interrupted the compressor cable at the compressor input - this preserves the fusing, pressure switch if there is one and so on. Wires run back to the hole in the toe-board, hidden where possible There are two wires from the redundant Throttling Valve socket, one to provide 0volts, the other to provide 12volts from the three points that provide voltage on any of the "Upper" cool switch positions. To make it easier to wire up I put bullet connectors near the toe-board. Because the temperature is not easily variable - you must push a "SET" button followed by a "-" or "+ button and "SET" again - it is not practical to vary the temperature set, but in practice I find on the CX it stays at 21C. So the whole lot could be put in the engine bay but I suspect the electronicals would have a short life. Alan D. Roll on heat waves! | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 325 Registered: 10-2009 |
I've just received a W3230 and the output relay is rated at 20Amps so I will try it without the SSR. It is a neat package and I would like to have it visible but it's difficult to find an oblong space hat would look right. In the little shelf/cavity above the passenger's feet (RHD) is convenient but hidden. Alan D. | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 326 Registered: 10-2009 |
While I was having lunch it occurred to me that the 12volt supply should be taken from the feed to the compressor. What a twerp, it's obvious and does away with the complication of tapping into the ex-Throttling-Valve socket, and hence, one wire. Alan D. | ||||
| Mark Aldridge Frequent User Username: mark_aldridge Post Number: 748 Registered: 10-2008 |
Thanks Alan,I await results. It would be a great improvement on the T1& Shadow1. I may be able to adapt this to control the temperamental system on my 1990 Mulsanne as well, by controlling the water valve. Mark | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 327 Registered: 10-2009 |
The cubby-hole is officially called "The Parcel Shelf". If there is a convenient earth point around wherever you decide to mount the unit or run the wires there is no need to fiddle about with any connectors into the Throttling Valve plug. I've tried it and it works. The system Mk2. uses a W3230 available from an Ebay near you. It uses two wires from the compressor plug : 1) Disconnect the live feed to the compressor and extend that wire with a spade connector through the toe-board. 2) Run a wire via a new spade connector from the compressor clutch through the toe-board. These two wires will be joined by the relay to run the compressor. Wire 1 is connected to the live feed (12volts) on the W3230 or the controller of your choice, AND to one leg of the output relay. Wire 2 is connected to the other leg of the output relay. Find an earth point and connect it to the -ve terminal on the controller. When any "cooling" position is selected on the Upper Air switch, wire 1 becomes live with 12volts. The controller wakes up and decides if the temperature is above the set point. If so it switches the relay on which switches the compressor clutch on. If not, not. Bob's your uncle. There is a trivial set-up to perform. By pressing the SET key quickly the target temp can be adjusted by the "+" and "-" keys. By pressing SET for a few seconds the internal parameters can be set. The important one is the first one, set by default to H for heating. Press "+" or "-" to change it the C for cooling, then press SET again. If I find a W3230 manual I will post the source here. If anyone else finds one, please ditto. There are several other parameters like time delay before switching the relay and hysteresis around the setpoint. There are Youtube videos of varying quality which describe the essentials. I will post a new item describing the parameters and how to set them later, if anyone needs it. Alan D. | ||||
| Mark Aldridge Frequent User Username: mark_aldridge Post Number: 749 Registered: 10-2008 |
Alan, where did you mount the temperature sensor on your T1. Mark | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 328 Registered: 10-2009 |
Mark, it is to the left of the oblong vent (RHD car, remember). It sticks out of the "crease" where the two pads above and right of the passengers knees meet in a corner. The wires to the sensor are pushed into the gap and the head is a centimetre out into the air. I estimate that because the vent blasts out cold air it draws the ambient air with it and this draught from the volume in the passenger foot-well flows over the sensor. As I've said, when we have the next heat-wave there will be an opportunity for fine tuning. But it's September, so.....?? Alan D. | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 329 Registered: 10-2009 |
The ideal place to put the control box is in the recess left when the ashtray is discarded. Putting it in the "parcel shelf" is not ideal. The temperature could be twiddled without crawling or fumbling. The wiring could be hidden behind the left trim panel on the side of the aircon switch box. BUT, I can't see how to remove it. The tech manual is vague - it says lever it off with a wedge-shaped thing. This is serial no 10630 and I can not find it in the Parts Cat. Any guidance about where to lever in which direction would be welcome. Alan D. | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 330 Registered: 10-2009 |
The panel needs brute force applied to the upper edge. A corner comes out and the rest can be encouraged to follow. Held in by spring clips and 50 years of .... what?? Just being there. (Who has seen the Peter Sellars film "Being There"? Magic. If you haven't, you should.) The final (probably) version of the cabin temp control now sits (or will soon) in the space left by the ex-ash-tray, with a matt black surround. Two wires to the suppressor clutch and one ground wire to the body ground immediately below the ex-ash-tray casing. There is a channel from the ash-tray recess forwards to the space at top front of the footwell. Then a hole in the toe-board. The NTC (Negative Temperature Coefficient) resistor, in a little SS tube, sits in the airflow out of the footwell. Patent not pending. Alan D. | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 331 Registered: 10-2009 |
Hi Y'All. Here is the installed final (probably) version of the automatic cabin temperature control. It only comes into play when the cooling function is selected. Two wires from the compressor clutch and one earth from the earth point below the ash-tray case plus the twin wire to the sensor (not quite visible at the top of the pic) wedged between the cheeks of the trim pads to the right of and above the passenger footwell. Alan D.  | ||||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 728 Registered: 07-2015 |
That looks really er,, cool lol | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 355 Registered: 10-2009 |
Thia has now been tested during a longish drive on one of the rare heat-wave days in UK. It worked fine, with the cabin temp showing as 29C it slowly brought it down to 23C in about 10 minutes, but there was only 800grams of gas in it. I have now put in the recommended 1.05 kg and it seems to be a bit better with the air temp at the big vent at 13c on full-speed fan. More info when the next heat-wave arrives. | ||||
| Alan Dibley Frequent User Username: alsdibley Post Number: 356 Registered: 10-2009 |
Incidentally the controller can be found on Ebay by searching W3230. Alan D. |
Original SY/SY1 R134a Conversion Charge Levels