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#1
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85 300D turbo pristine w 157k when purchased 161K now 83 300 D turbo 297K runs great. SOLD! 83 240D 4 spd manual- parted out then junked |
#2
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No. If it is a must then all ac shop will be out of business or they charge you exorbitant amount of money.
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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed. ![]() W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html 1 X 2006 CDI 1 x 87 300SDL 1 x 87 300D 1 x 87 300TDT wagon 1 x 83 300D 1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry. |
#3
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It seems this is the only forum that says nitrogen/R22 at 200 psi is the only way to find leaks. But if the test is invalid when there is liquid oil in the system, the test is not very practical is it?
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85 300D turbo pristine w 157k when purchased 161K now 83 300 D turbo 297K runs great. SOLD! 83 240D 4 spd manual- parted out then junked |
#4
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The MB AC FSM shows a tool for injecting oil into the system while the system is still under pressure.. meaning after you have installed the refrigerant.... If that is what Vstech was meaning ... I am not sure what his statement might have been in response to....
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1980 240d , chain elongation, cam marks reference: http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html evap fin cleaning: http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator A/C thread http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html |
#5
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You can pressurize the system with oil in it. Liquid is in-compressible, so the oil just sit there and acts like a thicker tube. As I have said before, A/C is very simple, important thing is to take safety precaution. I am not an A/C professional but I know enough to DIY or do R134a conversion.
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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed. ![]() W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html 1 X 2006 CDI 1 x 87 300SDL 1 x 87 300D 1 x 87 300TDT wagon 1 x 83 300D 1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry. |
#6
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Your local Welding supply shop. Ebay for R22 in 15 oz can... which I am still trying to figure a way to split three ways evenly... I guess an accurate scale would be good too.. just like you would do the refrigerant if you used a big tank to install it...
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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread "as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do! My drivers: 1987 190D 2.5Turbo 1987 560SL convertible 1987 190D 2.5-5SPEED!!! ![]() 1987 300TD 2005 Dodge Sprinter 2500 158"WB 1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere! Last edited by vstech; 06-06-2011 at 06:12 PM. |
#7
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Good start..
Except R22 in the amount of FOUR Ounces... put into an automotive system with nitrogen to pressurize it.. IS LEGAL.... per EPA... so that people can test under pressure..as you recommend... the reason pressure is needed is so that the orings involved are in their WORKING position.. not being pulled IN by vacuum... when they need to hole being pushed out by pressure...
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1980 240d , chain elongation, cam marks reference: http://www.peachparts.com/shopforum/showthread.php?threadid=10414 http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html evap fin cleaning: http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator A/C thread http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html |
#8
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So what tools are necessary to pressurize the system with something such as nitrogen or co2? I have always done the vac-down method, but that's because I was none the wiser...
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#9
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You were doing the correct thing ... that is for getting the moisture out...so that acid does not form from the mixing of moisture and the oil in the system... causing flakes to come off the inside and plug up tiny holes ..like in the TXValve.
We are just saying that THEN... to test for leaks... you need pressure.. you can use a normal set of hoses and gauges... there are regulators which fit on the nitrogen tanks just like Oxy or Acet... then that hooks to your AC gauges and you open the proper valves... I have a nitrogen tank and gauges...will post pics... but can not find my dang camera... been missing for four days...
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1980 240d , chain elongation, cam marks reference: http://www.peachparts.com/shopforum/showthread.php?threadid=10414 http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html evap fin cleaning: http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator A/C thread http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html |
#10
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Great question. several levels of answers can be dependent on what the 134 "conversion" entailed. first, the Oil in the system. if you do not know what kind was used, it's best to replace the compressor, the expansion valve, and the compressor manifold, with the dryer and flush the remaining coils with oil/refrigerant flush, then add the correct amount of mineral oil to the system, pulling a hard vacuum, then weighing in the correct volume of R12. this is the BEST method to convert back to 12. PAG oil is not compatible with R12, Ester is. if you don't know, it's best to assume PAG was used, and do it right. however, since doing it wrong will destroy your compressor, requiring you do do all that stuff, if the wrong oil is used, and will not if Ester is in there, simply evacuating the refrigerant, measuring how much oil came out with it, and replacing that with the same amount of ester oil, then flowing the weighed amount of R12 will put the system back to R12. however you will still have the 134 fittings on the system... if you try to remove them, you can damage the lines (don't ask how I know this) this is why it's needed to replace the compressor manifold. then lastly the 134 sticker needs to be removed.
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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread "as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do! My drivers: 1987 190D 2.5Turbo 1987 560SL convertible 1987 190D 2.5-5SPEED!!! ![]() 1987 300TD 2005 Dodge Sprinter 2500 158"WB 1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere! Last edited by vstech; 06-06-2011 at 06:06 PM. |
#11
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When I last evacuated and charged the system I used ester oil. I don't know what the car originally came with. I do plan on changing the compressor. However, if I could run the system on R12 for a while before changing the compressor and any lines, that would suit me nicely. Are you saying that I cannot swap the R134 fittings for R12 fittings without damaging the lines? Or, are you saying I must be careful or I will damage them? |
#12
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Removing R-12-to-134a-adapter fittings is primarily dependent on the original conversion. Since these kits are sold in any autoshop they may/may not have been "properly".
Some may have been spot-brazed in place, others are simply screwed on. Some kits appear to have thread-locker on the new fittings while others don't. Some conversions only changed the low-pressure/blue/"fill-port" on the top-front of the engine to a 134a fitting and left the original R-12 high-pressure/red/"service-port" alone. Modifications to fittings may affect the integrity of the schrader valve directly beneath it. The valves should have caps with O-rings in them. Before attempting any conversion/de-conversion you really need to inspect the whole system and be prepared to invest in new components where necessary. This includes the proper operation of the heater and the cooling system of the car. Some new components (e.g. R-4 compressors) may not honor the warranty if used in an R-12 "de-conversion". You need to decide if the warranty vs. performance trade-off is worth it when selecting what refrigerant you use. The A/C lines and fittings, even though they're on an otherwise metric car, are SAE sized. Having the right tools is also very important. You really cannot assume anything when you're working on the A/C. |
#13
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I’m primarily concerned about the W123, but other vehicles are relevant in this thread. Is this everybodys’ observation on all Daimler vehicles of general interest here (115/123/124/126) that may have run R12? I will have my system open and therefore will plan to replace all o-rings with new green ones and the appropriate nylog for R-12. But want to be double sure that I’m using the right sized ones. I assume the fittings and o-ring sizes are associated with each other?
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Current Diesels: 1981 240D (73K) 1982 300CD (169k) 1985 190D (169k) 1991 350SD (116k) 1991 350SD (206k) 1991 300D (228k) 2008 ML320 CDI (199k) 1996 Dodge Ram CTD (442k) 1996 Dodge Ram CTD (267k) Past Diesels: 1983 300D (228K), 1985 300D (233K), 1993 300D 2.5T (338k), 1993 300SD (291k) |
#14
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"Having the right tools is also very important."--Yak
When dealing with AC lines.... it is always suggested that two wrenches be used.. and often the proper wrenches will be what is called ' Line wrenches " or "?"... these are open end wrenches which wrap more than 180 degrees around the nut. But are still large enough on the open side to fit over the tube next to the nut or fitting... so they can be used in tight places to protect the line from being crunched...which is the most important place to exercise caution because having to replace the line in a tight place is really a chore.
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1980 240d , chain elongation, cam marks reference: http://www.peachparts.com/shopforum/showthread.php?threadid=10414 http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html evap fin cleaning: http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator A/C thread http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html |
#15
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system..
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1980 240d , chain elongation, cam marks reference: http://www.peachparts.com/shopforum/showthread.php?threadid=10414 http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html evap fin cleaning: http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator A/C thread http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html Last edited by vstech; 06-21-2011 at 09:33 AM. |
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