A/C Compressor Seal? R134 R12? Huh?
05-30-2002, 03:30 PM
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A/C Compressor Seal? R134 R12? Huh?
My mechanic told me I have a main seal failure on my A/C compressor. So these are my options as I see them. Buy a new compressor from Vertex Auto for 300.00. And hope that fixes the problem, or buy the Bolt-On Kuehl Compressor R134 Kit from the Griffiths website for 700.00. But then I have to get new hoses and a dryer as well, is that right? Or just put my car away till fall. Any advice on this along with any financial grants would be appreciated.
~Q
~Q
05-30-2002, 03:52 PM
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just get a reman original unit from griff for about $250 and a new dryer from partsbin.com for cheap. new o-rings all around would be nice. griff will sell you the r-134a connections and oil too. call him and work out a solution.
05-30-2002, 04:47 PM
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Quinn-
I'm enduring this same process as we speak.
I purchased the Griffith's setup which includes the dryer, compressor (Khuel), 2 hoses, and the oil ($699 total).
For insurance (so to speak) I also ordered replacement Thermal Expansion valves (I have Rear A/C).
My system had been converted to R134a, so all of the orings (supposedly) had already been replaced.
My parts from Griffiths will arrives on Monday (hey....it's 90 here today), and I WILL have the job done before the SITO's get together.
I'll post later with an update.
hth-
I'm enduring this same process as we speak.
I purchased the Griffith's setup which includes the dryer, compressor (Khuel), 2 hoses, and the oil ($699 total).
For insurance (so to speak) I also ordered replacement Thermal Expansion valves (I have Rear A/C).
My system had been converted to R134a, so all of the orings (supposedly) had already been replaced.
My parts from Griffiths will arrives on Monday (hey....it's 90 here today), and I WILL have the job done before the SITO's get together.
I'll post later with an update.
hth-
05-30-2002, 05:35 PM
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Myself, maybe buy the compressor from my donor shark. It's R-12
R12 cools better than 134a. You still can buy a new dryer core. I wouldn't change to R134a. If r12 is too expensive. Use Hot Shot, it's cheaper than r12, a very close replacement for r12 as well.
R134a cooling capacity is lower than r12. Just my .02 cents worth.
Maybe give me a call, I can explain more on the phone. Might want to clean the evap coil, and the blower motor for more efficient heat transfer, and more air into the cabin.
John D.
'85 928 Auto, Black
R12 cools better than 134a. You still can buy a new dryer core. I wouldn't change to R134a. If r12 is too expensive. Use Hot Shot, it's cheaper than r12, a very close replacement for r12 as well.
R134a cooling capacity is lower than r12. Just my .02 cents worth.
Maybe give me a call, I can explain more on the phone. Might want to clean the evap coil, and the blower motor for more efficient heat transfer, and more air into the cabin.
John D.
'85 928 Auto, Black
05-30-2002, 06:36 PM
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Q -
My '89GT had sat for a long time before I bought it and it was road-ready again. Turns out the AC was not just leaking, but shot - compressor seals, hoses, o-rings, rear evap, expansion valve, etc.
In talking through the alternatives, the AC guy (who has done LOTS of 928's) recommended staying with the Porsche compressor. He felt it was more heavy duty than some of the available replacements (e.g., Sanden rotary, etc.).
Another decision was refrigerant (R12 or R134). Not much difference cost wise. He assured me that he could get a R134-based system to be as cold as a R12 system.
So I took his recommendations (i.e., Porsche compressor and R134 refrigerant) and now am enjoying a truly ice cold system.
HTH..... <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
My '89GT had sat for a long time before I bought it and it was road-ready again. Turns out the AC was not just leaking, but shot - compressor seals, hoses, o-rings, rear evap, expansion valve, etc.
In talking through the alternatives, the AC guy (who has done LOTS of 928's) recommended staying with the Porsche compressor. He felt it was more heavy duty than some of the available replacements (e.g., Sanden rotary, etc.).
Another decision was refrigerant (R12 or R134). Not much difference cost wise. He assured me that he could get a R134-based system to be as cold as a R12 system.
So I took his recommendations (i.e., Porsche compressor and R134 refrigerant) and now am enjoying a truly ice cold system.
HTH..... <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
05-30-2002, 07:53 PM
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On the claim that R134a system can be made to be just as cold as R12.
I doubt that the mechanic can back his claim up, with out spending big money. I work for York International as a refrigeration service tech. I have worked in the field as a reclaim specialists as well( a profession that takes used refrigerants, tests them for chemical composition, then put a batch thru a purifing sytem to bring the used refrigerant back to ARI standards). If you look at any temperture pressure charts of R12 compared to R134a, at any temp you would find his claim is bogus. The tonnage of refrigeration is lower with R134a through out the slope of refrigeration. This is fact. If one says he can make R134a as cold as R12, ask him how?? Can't be done. If he over charges the unit, the compressor will be damaged. It might even go hydraulic. If he changes the expansion valve, he needs to change the evap, and or condensor to compensate for superheats and subcooling desired, now you have to change the volume of air travelling over the coils. Now it costs big money. Being a bigger system, can you meet the superheats, and subcooling needed to put out the tonnage as the same of a smaller cheaper R12 system, probably. Then to do all of that, just to save a few dollars for a type of refrigerant????
Buy some 'Hot Shot' or 'MP39', Save yourself some money. It costs less than R134A, as well.
Now ask the mechanic about any metal that was exposed inside the system of the original R12. Any metal over time will start to corrode by the shear chemistry of the change in refrigerants. Refrigerants act differently with metals, and oils. You might not have a leak for 1-3 years but it will corrode the metal, and any oring that is left from the prior refrigerant stands a greater chance to leak over time. No one ever claimed that orings will last with R134a as long as ones with R12. Look how many cars after 1993 have problems due to oring failures.
How do I know this. I have gone through schooling, and work at a company that has just about 3/4 of the worlds refrigeration business. When a major corporation makes and services million dollar plus machines, they will not stnd for customers being misinformed, then have them go back to the factory for warranty repairs due to being misinformed.
This is not bashing any members/users. Just be informed. If one says he can make it the same with something else, ask how??
John D.
'85 928 auto, Black
I doubt that the mechanic can back his claim up, with out spending big money. I work for York International as a refrigeration service tech. I have worked in the field as a reclaim specialists as well( a profession that takes used refrigerants, tests them for chemical composition, then put a batch thru a purifing sytem to bring the used refrigerant back to ARI standards). If you look at any temperture pressure charts of R12 compared to R134a, at any temp you would find his claim is bogus. The tonnage of refrigeration is lower with R134a through out the slope of refrigeration. This is fact. If one says he can make R134a as cold as R12, ask him how?? Can't be done. If he over charges the unit, the compressor will be damaged. It might even go hydraulic. If he changes the expansion valve, he needs to change the evap, and or condensor to compensate for superheats and subcooling desired, now you have to change the volume of air travelling over the coils. Now it costs big money. Being a bigger system, can you meet the superheats, and subcooling needed to put out the tonnage as the same of a smaller cheaper R12 system, probably. Then to do all of that, just to save a few dollars for a type of refrigerant????
Buy some 'Hot Shot' or 'MP39', Save yourself some money. It costs less than R134A, as well.
Now ask the mechanic about any metal that was exposed inside the system of the original R12. Any metal over time will start to corrode by the shear chemistry of the change in refrigerants. Refrigerants act differently with metals, and oils. You might not have a leak for 1-3 years but it will corrode the metal, and any oring that is left from the prior refrigerant stands a greater chance to leak over time. No one ever claimed that orings will last with R134a as long as ones with R12. Look how many cars after 1993 have problems due to oring failures.
How do I know this. I have gone through schooling, and work at a company that has just about 3/4 of the worlds refrigeration business. When a major corporation makes and services million dollar plus machines, they will not stnd for customers being misinformed, then have them go back to the factory for warranty repairs due to being misinformed.
This is not bashing any members/users. Just be informed. If one says he can make it the same with something else, ask how??
John D.
'85 928 auto, Black
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05-30-2002, 08:52 PM
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Thanks to all who responded, I am assuming mine was filled with the R12, as far as buying a rebuilt one I think the whole replacement kit offered by griff is the safe way to go, so Jay let me know how it turns out, I have the same car so tips and all would be grateful. Again thanks for the responses.
05-30-2002, 09:18 PM
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John D,
GREAT info! Wish I'd known that 6 months ago!! I have no doubt that R12 is a superior refrigerant (to R134) and may provide for a colder system. All I know is that the temp coming out of the vent is ~38*F and that is plenty cold! Certainly enough to freeze my butt off!
Thanks!
GREAT info! Wish I'd known that 6 months ago!! I have no doubt that R12 is a superior refrigerant (to R134) and may provide for a colder system. All I know is that the temp coming out of the vent is ~38*F and that is plenty cold! Certainly enough to freeze my butt off!
Thanks!
05-30-2002, 10:55 PM
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Quinn, I'll keep you posted (as well as others).
In as far as R12 vs. R134a...well, it's no doubt a bueracratic issue (at best).
Near as I can tell, the Latent Heat of Vaporization for R12 in a system properly charged should produce vent air temps in the region of ~35 degrees F. R 134a should produce temps in the area of 38 degrees F. A minor difference IMHO.
Looking at the expansion valve (which is filled with R22) in the system, it acts based on vapor stream conditions, based on the user's demand setting for optimum flashing of the refrigerent (sp?) - ie the system freon. Other than ensuring that the expansion valve internals are ok (or not stuck), the expansion valve should have little, if any, bearing on system performance.
Not to quibile, but many times moajor corporations have a tendency to mix facts with fiction (especially if it can be translated to an increase in sales - ie profit).
I wholeheartedly agree that the original Nippondenso compressor is a very 'healthy' uint (ie beefy). However, the teflon coated pistons will wear and the rings do go south after a period of time (like anything else on our cars). The swash plate design is efficient as well as durable. It is the pistons (rather the rings) which are the apparent weak link in this scenario.
After 110K miles (with dubious previous owners), I feel that the time has come for this owner to enjoy COLD air, and at a reasonable price.
I will keep all informed.
Best Regards-
In as far as R12 vs. R134a...well, it's no doubt a bueracratic issue (at best).
Near as I can tell, the Latent Heat of Vaporization for R12 in a system properly charged should produce vent air temps in the region of ~35 degrees F. R 134a should produce temps in the area of 38 degrees F. A minor difference IMHO.
Looking at the expansion valve (which is filled with R22) in the system, it acts based on vapor stream conditions, based on the user's demand setting for optimum flashing of the refrigerent (sp?) - ie the system freon. Other than ensuring that the expansion valve internals are ok (or not stuck), the expansion valve should have little, if any, bearing on system performance.
Not to quibile, but many times moajor corporations have a tendency to mix facts with fiction (especially if it can be translated to an increase in sales - ie profit).
I wholeheartedly agree that the original Nippondenso compressor is a very 'healthy' uint (ie beefy). However, the teflon coated pistons will wear and the rings do go south after a period of time (like anything else on our cars). The swash plate design is efficient as well as durable. It is the pistons (rather the rings) which are the apparent weak link in this scenario.
After 110K miles (with dubious previous owners), I feel that the time has come for this owner to enjoy COLD air, and at a reasonable price.
I will keep all informed.
Best Regards-
05-30-2002, 10:56 PM
#11
Three Wheelin'
Dozman,
There is allot of discussion on auto A/C sites about the benefit of using a new dual-flow condenser if switching to r134. Are you familliar with that topic? I hear it helps the cooling ability of R134.
Generally speaking, I am not a fan of conversion to R134 for the 928. IMO, a tight, properly serviced A/C system in our 928's should be kept r-12. I posted a thread about what I did to my A/C system including new barrier hoses. The r-12 system in my car works great.
Greg
There is allot of discussion on auto A/C sites about the benefit of using a new dual-flow condenser if switching to r134. Are you familliar with that topic? I hear it helps the cooling ability of R134.
Generally speaking, I am not a fan of conversion to R134 for the 928. IMO, a tight, properly serviced A/C system in our 928's should be kept r-12. I posted a thread about what I did to my A/C system including new barrier hoses. The r-12 system in my car works great.
Greg
05-31-2002, 01:02 AM
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the only prob with r12 is it will cost about $200 for the freon and whatever joe mech charges to install. i did the conversion, reman n'denso unit, pulley bearing, new dryer, o-rings and hoses. i'm satisfied and you would be too. tint helps a lot. it's like a microwave under that big rear glass. take the plunge and do the conversion. i'm not going to enter the this or that debate, all i'm saying is the conversion works. kind of like blonds or redheads, both will do the job effectively (or be dismissed.) might as well buy new equipment and cheap freon vs hack job and expensive freon, you make the call.
05-31-2002, 03:24 AM
#13
[quote]Originally posted by Jay Wellwood:
[QB]Near as I can tell, the Latent Heat of Vaporization for R12 in a system properly charged should produce vent air temps in the region of ~35 degrees F. R 134a should produce temps in the area of 38 degrees F./QB]<hr></blockquote>
I'd say you can tell pretty darn well Jay. When I replaced the expansion valve in my 928 I left the system R12. When I worked on my Toyota I converted it to R134. The 928 got 34 degree vent temperatures, and the Toyota 38. Yes, the R12 in the 928 is colder, but the R134 in the Toyota is plenty cold enough. During the A/C test drive after the conversion, with the A/C on maximum it was getting so cold in the car that condensation was forming on the outside of the windshield. It got so bad I had to turn on the windshield wipers to see.
[QB]Near as I can tell, the Latent Heat of Vaporization for R12 in a system properly charged should produce vent air temps in the region of ~35 degrees F. R 134a should produce temps in the area of 38 degrees F./QB]<hr></blockquote>
I'd say you can tell pretty darn well Jay. When I replaced the expansion valve in my 928 I left the system R12. When I worked on my Toyota I converted it to R134. The 928 got 34 degree vent temperatures, and the Toyota 38. Yes, the R12 in the 928 is colder, but the R134 in the Toyota is plenty cold enough. During the A/C test drive after the conversion, with the A/C on maximum it was getting so cold in the car that condensation was forming on the outside of the windshield. It got so bad I had to turn on the windshield wipers to see.
05-31-2002, 01:34 PM
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Thom’s A/C Service Essentials:
RULES:
If you open the system: Replace the dryer. Vacuum the moisture out.
If you convert to R134A, flush the old oil (& contaminants) out. Change o-rings.
If o-rings are exposed, replace them with new ones. Oil 0-rings before installation.
RECOMMENDATIONS:
Do not convert to R134A. See REFRIGERANTS below.
If you open the system, flush it too. By now it may have 2 or 3 times over the normal volume of oil plus contaminants.
When needed, buy a new compressor or rebuilt original. Don’t try to rebuild it yourself.
Have refrigerant filled by a pro. You can blow out a hose or compressor by filling with cans, and/or without the proper gauges and/or methodology.
Replenish the pulley driven fan clutch fluid - get it from Toyota - Thickest part number version is 08816-10001
Clean the condenser – looks like a front radiator.
Expansion valve(s) may need to be changed – especially after compressor failure.
Old hoses may leak. Some new compressors come with new hoses too.
FLUSH & FILL: To flush the system use professional equipment and/or: Disconnect hoses and remover dryer. Flush out the old components with a cleaning fluid, and proper equipment. (Do not use compressed air, since it puts moisture into the system, and can generate corrosive acid compounds. Incompatible oils or contaminants can ruin your compressor.) You should put oil into a new compressor, and turn it manually a few times before you turn on the A/C, and after flushing. Connect hoses, and vacuum out the system immediately after the flush. Do not expose the inlets of the new receiver/dryer and compressor to the atmosphere until you are ready to add oil and connect hoses.
ORIFICE TUBE: There is no orifice tube. The dryer filters contaminants. In American cars the orifice tube is a filter made of fine screen, plastic, and o-rings. Replacement of the orifice tube and dryer are required for warranties on American compressors.
HEATER CONTROL VALVE: The A/C will never be cold with a defective heater control valve or vacuum leak that impacts the valve. The valve (under the air filter) will by default bleed hot water into the heater core until all vacuum leaks on the dash side of the firewall (and engine compartment extension/heater control valve) are fixed. The valve can be defective even if vacuum is good. The valve can be installed 180degrees reversed. The white side of the valve (on my model) goes toward the firewall side. (If you replace the valve, also replace the 3-inch long water hose connected to it.)
REFRIGERANTS:
If you have R12, stick with it, or for less expensive refills - Hot Shot or MP39 sound good as inexpensive, compatible refills. A R134A conversion can reduce efficiency 8-12%.
MORE INFORMATION OR PARTS: The Big 3 can provide parts. See the griffiths.com site for parts and info. See the link below for in depth discussions by people from whom I have derived some of my recommendations:
<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=14&t=001183" target="_blank">http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=14&t=001183</a>
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
RULES:
If you open the system: Replace the dryer. Vacuum the moisture out.
If you convert to R134A, flush the old oil (& contaminants) out. Change o-rings.
If o-rings are exposed, replace them with new ones. Oil 0-rings before installation.
RECOMMENDATIONS:
Do not convert to R134A. See REFRIGERANTS below.
If you open the system, flush it too. By now it may have 2 or 3 times over the normal volume of oil plus contaminants.
When needed, buy a new compressor or rebuilt original. Don’t try to rebuild it yourself.
Have refrigerant filled by a pro. You can blow out a hose or compressor by filling with cans, and/or without the proper gauges and/or methodology.
Replenish the pulley driven fan clutch fluid - get it from Toyota - Thickest part number version is 08816-10001
Clean the condenser – looks like a front radiator.
Expansion valve(s) may need to be changed – especially after compressor failure.
Old hoses may leak. Some new compressors come with new hoses too.
FLUSH & FILL: To flush the system use professional equipment and/or: Disconnect hoses and remover dryer. Flush out the old components with a cleaning fluid, and proper equipment. (Do not use compressed air, since it puts moisture into the system, and can generate corrosive acid compounds. Incompatible oils or contaminants can ruin your compressor.) You should put oil into a new compressor, and turn it manually a few times before you turn on the A/C, and after flushing. Connect hoses, and vacuum out the system immediately after the flush. Do not expose the inlets of the new receiver/dryer and compressor to the atmosphere until you are ready to add oil and connect hoses.
ORIFICE TUBE: There is no orifice tube. The dryer filters contaminants. In American cars the orifice tube is a filter made of fine screen, plastic, and o-rings. Replacement of the orifice tube and dryer are required for warranties on American compressors.
HEATER CONTROL VALVE: The A/C will never be cold with a defective heater control valve or vacuum leak that impacts the valve. The valve (under the air filter) will by default bleed hot water into the heater core until all vacuum leaks on the dash side of the firewall (and engine compartment extension/heater control valve) are fixed. The valve can be defective even if vacuum is good. The valve can be installed 180degrees reversed. The white side of the valve (on my model) goes toward the firewall side. (If you replace the valve, also replace the 3-inch long water hose connected to it.)
REFRIGERANTS:
If you have R12, stick with it, or for less expensive refills - Hot Shot or MP39 sound good as inexpensive, compatible refills. A R134A conversion can reduce efficiency 8-12%.
MORE INFORMATION OR PARTS: The Big 3 can provide parts. See the griffiths.com site for parts and info. See the link below for in depth discussions by people from whom I have derived some of my recommendations:
<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=14&t=001183" target="_blank">http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=14&t=001183</a>
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
05-31-2002, 09:05 PM
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I am 100% certain of my position on this topic due to my thorough very intense on-topic
training.
I will leave just one thought, I agree to disagree on certain topics here. If for any reason someone might be confused or in need of some advice or help with their a/c, being auto, residential, or commercial, feel free to contact me.
<img src="graemlins/r.gif" border="0" alt="[king]" />
John D.
'85 928 Auto, Black
training.
I will leave just one thought, I agree to disagree on certain topics here. If for any reason someone might be confused or in need of some advice or help with their a/c, being auto, residential, or commercial, feel free to contact me.
<img src="graemlins/r.gif" border="0" alt="[king]" />
John D.
'85 928 Auto, Black