| Author | Message | ||
     Alan H Olden Yet to post message Username: alan_olden Post Number: 1 Registered: 5-2009 |
My RR is a 1981 Silver Spirit which I purchased earlier this year (am now 3rd owner) and after having the suspension / steering serviced and adjusted I am now working on the A/C. It appears that there is a very small leak and the R134 refrigerant remains under pressure for about 2 months. My local air con mechanic suggests either the receiver dryer needs replacing and/ or the compressor (Delco type) needs retrofitting. I can get new receiver dryer ex UK for about $500 landed and have it fitted. My question is whether anyone knows where to source a replacement / swap compressor. The RR service garage in Sydney suggested I invest up to $5k to have a complete overhaul! This is obviously expensive and I something I am trying to avoid. Any suggestions welcome. Many thanks Alan Olden | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 461 Registered: 6-2006 |
Hi Alan, any suggestions . . . keep away from main agents! I'm not sure what you are saying here: You have a small leak. My local air con mechanic suggests either the receiver dryer needs replacing and/ or the compressor (Delco type) needs retrofitting. Are these sentences connected? I'd be of the opinion that if your gas leaks out in two months , it's not a small leak! If your air con system is dirty outside, get everything washed off and get some UV leak detector dye in the system. A leak that large will show up pretty quickly. Our receiver dryers over here cost between £100 and £240 depending on the chassis number. Probably about £50 shipping. Not sure what that works out to in aus$ You shouldn't need a complete overhaul unless somebody has stuck 134a in on top of 12, without an oil change etc. A complete system change in not normally needed unless it's suffering from 'black death'. However saying that, it is very helpful in maintaining marble tiled offices with three office staff to one mechanic in the manner they have become accustomed to.  | ||
| Larry Halpert Prolific User Username: larry_halpert Post Number: 125 Registered: 9-2003 |
I don't know how this compares in cost, but no matter how high shipping can be made from the US to Australia, it would be tough to rack up the cost of the UK or dealer prices: Send your current old one to Classic Auto Air in Tampa, FL (813-251-2356) http://www.classicautoair.com/Other_Models_Air_Conditioning_AC.html They will replace the dessicant with the newest that works with both R12 & R134, and make sure there are no leaks - for $58. Also, for new replacement, here are a couple of choices as I don't know which VIN number you have: -A/C Accumulator Drier: Four Seasons/Murray #33176 or Ready-Aire #3596N fits cars with chassis numbers 8671-16930 Rolls part CD6302, and verified on '84 Spirit VIN#9542. It is about $30. A different accumulator was used in some cars during this production range, so just be aware to be sure. -A/C Valve-In-Receiver Unit: Four Seasons/Factory Air #38601 or Ready-Aire #3600 VIR assembly fits cars with chassis numbers 1001-8670. Available here: Summit Racing. for $59.69. Rolls part number UD22494. http://www.summitracing.com/parts/PLR-3600/?image=large There is also a repair kit for this unit giving you new dessicant bag & o-rings which is Four Seasons #34218. Larry http://mutley.hypermart.net/RollsSubstituteParts.html (Message edited by Larry_Halpert on 08 October 2009) | ||
| Bill Payne Experienced User Username: wimpy Post Number: 27 Registered: 1-2007 |
Regardless of system ills, contact the previous owner(s) to ascertain who did the change over from R12 to R134 and find out if the system was flushed. If not, have it flushed! But first: As mentioned earlier, do the dye to find leak source. Compressor going south can cause this kind of leak. Rule of thumb. Pull a vacuum for at least 30 minutes to insure leaks are non-existent, after replacing parts. Replace the orifice tube & dryer anytime you go into the system. | ||
| Omar M. Shams Frequent User Username: omar Post Number: 73 Registered: 4-2009 |
Alan, As others have said - I will reiterate the importance of finding the source of the leak and plugging that. Without ensuring a leak-free system, you are on a hiding to nothing. Leak detection is an art in itself, but experienced AC shops can assist if it becomes too daunting for the DIY man. Once you are confident that you have found the leak and cured it, note the wise words of Bill's rule of thumb above. We tend to use nitogen to pressurise the system when we want to check for leaks to see if the system holds static pressure overnight. The slightest drop in pressure and it is back to leak detection again. | ||
| Gus Brogden Frequent User Username: gus Post Number: 59 Registered: 2-2008 |
If your A/C mechanic says either the receiver or the compressor need changing, I say you have the wrong man on the job. It's not difficult to find and repair a refrigerant leak, but the "shotgun" approach to replacing parts is an expensive way to do it. However, if components were replaced until the leak stops, it would be costly but successful. If the compressor worked without seizing with 134 previously, it will work fine now, and shouldn't require an oil flush. Dont get anyone to do your work unless they will accurately diagnose and quote it for you. Changing the dryer every time you repair leaks or open sealed systems is a must. Dye and a UV light and dry nitrogen under pressure with soap bubbles are ideal ways to search for leaks. Pay particular attention to any areas that are oil stained. DO NOT run the system with nitrogen in it!!! Proper evacuation with a vacuum pump to 50 microns before charging with refrigerant is ideal. | ||
| Gus Brogden Frequent User Username: gus Post Number: 60 Registered: 2-2008 |
BTW, there are tons of choices for new receivers, nowhere close to $500. Check Larry's link above. It is sage advice. I walked into my local auto parts retailer, went through his catalogue, and found an almost identical replacement for well under $100. | ||
| Bill Payne Experienced User Username: wimpy Post Number: 28 Registered: 1-2007 |
Gus is spot on. I was too focused on the cure vs the guy's diagnosis. The dryer never leaks, but I would still confirm the procedure for the upfit to R134. Speaking from experience, residual R12 and oil will kill a compressor. You might find this helpful, picture & pricewise. This is the AC part of the catalog done by a local wholesale automotive warehouse. Most of the products are new, some are re-moanufactured. http://www.autosupplyhouse.com/pdf/catalog/05CAT09_AC.pdf | ||
| Gus Brogden Frequent User Username: gus Post Number: 61 Registered: 2-2008 |
There wont be any residual R12 with proper evacuation. With improper evacuation, R12, nitrogen, atmosphere, moisture, and any other non-condensables are a problem. They will each exert a pressure as if they occupy the space alone, (Gay Lussac's law) and drive compressor discharge pressures and condensing temperatures sky high. This overloads compressors, destroys compressor valves, and dramaticlly reduces refrigeration efficiency. R 134 must only be used in a compressor that contains poly olester oil. Any doubt and the oil should be dumped and a new oil charge put in. A compressor designed for R12 will work just fine with R134, (about the same volumetric efficiency) but the oil MUST be changed. A safe bet is less than 3% residual mineral oil in the WHOLE system. During R12 to 134 retrofit, it's very important to remember that the oil and refrigerant migrate through the system together. A compressor oil change to PAG may still leave a high (as much as 50%) residual mineral oil. More than enough to seize a compressor on R134. This constitutes multiple oil changes (a real pain). The only way to know for sure is to let the system run for a bit, pull some oil, and check its refractive index with a refractometer. Anything less is just guessing. Making sure the service tech knows what he's doing can save $ and heartache down the road. Make sure he is qualified. The synthetic oils used for R134 are very hygroscopic and readily absorb moisture from the atmpsphere. Buy small containers, and dont open them until you are ready to use them. Never use them from an old, previously opened container. | ||
| Alan H Olden New User Username: alan_olden Post Number: 2 Registered: 5-2009 |
Thanks to everyone who has responded. It is very helpful and gives me some much improved guidance. As fas as i know the uplift to R134 was essentially a drain, some dye was used but not overly conclusive. Indeed the advise i was given was very 'shotgun' with essentially some guess work. I have been given some contact no. of a guy is Sydney who does this special work for RR and B cars. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 462 Registered: 6-2006 |
Alan, as long as he doesn't charge 'special' prices as well ! When you say drain, do you mean oil drained? As long as there is enough dye in the system (and it doesn't take much) there's no reason why a system that leaks out over a two month period should not show a leak clearly. If there are no visible dye marks, check the expansion matrix drain pipe for signs of dye - if they leak, it can be hard to trace. It may not show up immediately in the workshop, but the beauty of it is the dye will remain near the leak for ages. Buy a UV torch from ebay - cheap from China - and do it in a dark garage or late at night. Take a look at the sight glass to check for dye colour. | ||
| Bill Payne Experienced User Username: wimpy Post Number: 29 Registered: 1-2007 |
When working on auto a/c systems,there really isn't a need for an experienced RR or B specialist. Here in the US, any reputable company that works on radiators typically also handles auto A/C work and can do whatever is necessary for whatever make or model they see. |
