How To Replace Compressor & Recharge System - AC Pics!

wolfman

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BMW 335d, Passat 2013 TDI SEL; Former - 1999 Jetta TDI, 1994 GMC Sierra 6.5 TD, 1983 Ford 6.9 IDI, 1986 Chevy 6.2 Diesel Pickup, VW Rabbit Diesel pickup
After searching the forums for a post on how to repair my air conditioning, I really didn't find anything in detail, so I just jumped in and did it myself. I have a 1999.5 Jetta with manual trans. The whole process took me about 5 hours, including a couple mistakes. By reading this post you can probably do it in about 3 hours with no complications. The symptoms I was having initially were poor cooling (compressor was engaged), then severe noise like a bucket of bolts, and eventually total loss of function, after a couple more days. The a/c button on the dash was lighting up, but there was no voltage at the wiring harness. There was little charge left in the system. I diagnosed this as compressor failure and a leak at the shaft seal, after inspecting all the hoses and the condenser in front of the radiator.

I ordered the following parts from Impex: AC Expansion Valve COST: $35.71 2. AC Receiver Drier COST: $69.97 3. AC Compressor
COST: $300.00. I'm not sure the expansion valve was bad, but I didn't want to take any chances of having to order more parts. In doing this job, I discovered that the receiver-drier is supposed to be replaced every 3 years, even if the system seems to be working OK. The receiver drier removes impurities and moisture and must be replaced whenever the system is open.

Next, I ordered 6 cans Enviro-Safe Industrial 12a for $45.00 from autorefrigerants.com. It turns out I only needed 2 cans to do this job, about 10 ozs., which is the equivalent of 32 ozs or R-134. The system calls for 750 g or 26.8 ozs. R-134a, The enviro-safe is a hydrocarbon, not chloro-or fluorocarbon. I purchased O-rings for the system, oil charge with R-134, and a gauge/connector at Advance Auto Parts for about $20.00 for all.

Now, on to the job. You will need the following tools: 17mm socket, phillips screwdriver, pry bar, adjustable crescent wrench, 4, 5, and 6mm hex keys, possibly wire cutters, solder and heat shrink tubing. If there is charge in the system, the environment will thank you if you take it to a shop to have the refrigerant recovered. Mine had already leaked out.

First, put the car up on jack stands in the front and remove the passenger side wheel, skid plate, and side skirt. You will see the compressor right at the bottom of the front of the engine:

Remove the serpentine belt by using a crescent wrench on the tensioner and just slip the belt off. Put it up out of the way and try not to let it come of the other pulleys.

Next, if there is charge in the system, make sure it's evacuated and then use the 6mm hex key to remove the refrigerant lines from the rear:






Place the hoses down on the ground so that any contaminated oil can drip out. I placed a wrench on them to hold them down. There was some oil, but not too much. You may see pieces of slivered metal in the oil. I also ran a bit of the new refrigerant through the suction port to flush out at least that line. If you use the enviro-safe refrigerant, you don't have to feel guilty about this.

Next, remove the electrical connector and use the 17mm socket to loosen the 2 bolts holding the compressor on (11:00 and 2:00):




Mine was in very tight and took some prying to get out, even after the bolts were removed. Just make sure not to drop it on your head. Save the bolts to re-use.

Next, remove the receiver-drier. This is located on the passenger side of the radiator. Mine was labeled "Parker" and "Made in USA!"

In order to remove it easily, remove the screw holding the refrigerant line on top of where you will be working:



Next, gently move the refrigerant line from which you just removed the screw. It's flexible enough to move without breaking if you are careful. Then use the 6mm hex key to remove the refrigerant line from the top of the receiver drier, seen in pic above. Get under the car and use the 6mm hex to remove the refrigerant line from the bottom. The top line was on very tight and connects to the condensor, so be very careful not to break it. Finally, use the 5 mm hex key to remove the hex bolt retaining the receiver-drier. You can then slip 1/2 of the holder out of a slot toward the front of the car.

Install the new receiver in the openingsame as the one you removed. The receiver/dryer goes in welded side up, at least in the replacement units...just check as the bottom line has three holes needed and the top just two:



slide the holder back together and reinstall the 5mm hex nut, but do not fully tighten yet. Remove the old o-rings from the refrigerant lines and replace with the appropriate size. Slide the receiver-drier up in the holder and align the opening with the connection to the condenser, then reinstall the 6mm hex nut into the top thread. Once it starts getting hard to turn, go ahead and fully tighten the retaining band with the 5mm hex, after you make sure it's up high enough in the slot. This will prevent you from torquing (and breaking) the condenser. The 6mm hex must be fully tightened so there is no gap between the refrigerant line and the top of the receiver. Next, reinstall the bottom refrigerant line after you replace the o-ring. You are ready to install the new compressor.

Locate the 17mm bolts and install the new compressor using them.

Reinstall the belt making sure it's on all the pulleys correctly. Next remove the factory plugs seen in the pic above using the 6mm hex. Replace the o-rings on the refrigerant lines and then install to the back of the compressor. Make sure there is a nice tight fit to the machined metal surface. In my car, the plug was a different style, an so I had to reuse the connector from the old compressor. If you have to do this, I recommend soldering the wires and then using heat shrink tubing:

It should look like this when you are done:



Slide the wire harness into its metal holder and then connect it.

Next, you may replace the expansion valve. It is located on the firewall in front of the passenger seat, and covered with a plastic insulator. The insulator unsnaps from the passenger side and has a hinge on the driver side. Here is a pic with the insulator already removed:



Using the 5mm hex, remove the first bolt holding the aluminum retaining clip seen in the pic above. Carefully slide the hoses out of the valve and replace the o-rings.

Use the 4mm hex to remove the other two hex nuts and then slide the valve off. Replace the o-rings. Here is the old and the new valve with the 4mm hex bolts:



Reinstall the new valve using the 4mm hexes first, then reinstall the aluminum retaining clip and the refrigerant lines. Replace the insulator. It only fits one way. Now, you are ready to test the system. Follow the directions with your gauge and install it to a can of oil charge. With the car off, snap the quick-connect onto the low side refrigerant line, located right near the receiver-drier. It has a black cap on it:

Open the valve on the can and let a little refrigerant into the system, then close the valve on the can. Note the pressure reading and wait 5 minutes. Make sure the pressure doesn't drop, although it may go up. If it goes down, you have a leak. Luckily, I did not. If there are no leaks, allow the oil charge into the system by turning the can upside-down. Now, get another can of refrigerant, pierce the top, and install to the lowside connector. Start the car and turn on the AC.

Open the can of ec-12a refrigerant and allow it into the system, slowly. Turn the can upside down, but not all at once - a little bit at a time. It will take the whole can. Check your pressure. Mine was about 35 psi.



It will probably take about another 3-4 ozs from a second can. DO NOT use the whole second can. It is too much.

Get inside the car and check your temp at the outlet on recirc mode. It should look like this:



Sweet! Now I have a/c again. And, it's colder than before using the EC-12a refrigerant. Good Luck.
 
Last edited:
Joined
Apr 27, 2003
Location
Stafford Virginia 22556
TDI
96 glx variant tdi
Nice write up. I am not flaming you, but because you didnt draw the system down, you have a small amount of moisture in it which will shorten the effective lifespan of the drier. Also... you may have a problem in the future if you take your car to any shop for a/c repair. Once they put a refrigerant identifier on it, they'll probably show you to the door. Basically, recovered r134a goes in this can, recovered r12 goes in that can, and since we only have 2 cans in the machine, bye bye. Contamination by strange refrigerants costs hundreds of dollars in filters that need to be replaced. So... we just don't work on anything but pure r134a or r12 systems. A pawn shop would have a cheap set of gauges for $50 or so, even Yellow Jacket sells a cheap set for that amount. You should check to see if your high side sensors are working as well, i.e. high pressure/overheat cut off, high pressure high speed fan turn on, etc. It's hard to beat that 32 degree reading however you got there.
 

PDJetta

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'04 Jetta GLS TDI Pumpe Duce Platinum Grey w/ Leather
Great write up and pictures! Good point about not pulling a vacuum. You may want to discharge and refill the system a couple of times with the extra refrigerant you bought to dilute the air and any moisture in the system.

--Nate
 

wolfman

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Thanks for the info. Is there really enough moisture in there to worry about? I thought the drier would remove that. I guess I have the cans - it wouldn't hurt to drain and refill.
 
Joined
Apr 27, 2003
Location
Stafford Virginia 22556
TDI
96 glx variant tdi
The principal purpose of drawing a vacuum is to lower the atmospheric pressure inside the system. Doing that "boils" water and eliminates it completely. The secondary purpose is to check system integrity. On really humid days like we've had lately, a good deal of moisture does get in there.... is it enough to damage something .. I'm not sure. I just go by how I was trained. It's sort of like trying to get the horse back in the barn now... I'd leave well enough alone and enjoy the 32 degrees.
 

Fortuna Wolf

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2002 Jetta TDI Auto Sedan
HC-12a does not need to be perfectly dry. In fact, you do not need to replace the drier in the system. Also, you can mix R-134a with HC-12a but its technically illegal to mix refrigerants. If you do have R-134a then you don't want water in the system though.
Let's review.
moisture + HC-12a = who gives a crap
moisture + R-134a = acid

Draw the system down to a vacuum to remove the R-134a, then release the vacuum and let air into the system. Then fill up HC-12a. No drier change necessary.

Otherwise... Wolfman, thanks for the writeup. If I ever have a problem I'll know what to do :)

Post if thou noticest improved mileage with the HC-12a (expect only 1-2mpg though).
 

wolfman

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vent temps are now down to 21 degrees F, after a couple weeks of use. I did purge the system to get out any moisture which may have been in there.
 

chirorob

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Mar 5, 2001
Location
Auburn, AL
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2002 Jetta wagon auto
Yea, 21F = frozen evaporator and some major damage. You might want to reduce your content by 1/2oz or so.
 

CaptainKirk

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Jul 8, 2005
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Kalamazoo, MI
TDI
Jetta, 2002, Black
How to Replace Compressor & Recharge System

I'm going through the same thing right now with one of my cars.
Impex: AC Expansion Valve COST: $35.71 2. AC Receiver Drier COST: $69.97 3. AC Compressor
COST: $300.00.
In looking at Impex, they have 3 drier's 3 expansion valves etc. How do I know which parts to order. Did you have any part numbers you could include? Does it make a difference? If I'm switching to ES 12a I probably don't want a expansion valve listed as R134 - correct?

Do I want a drier with or without a switch? I assume I don't need one with a switch if my AC was working before the compressor seized.

Do I need any special O-rings with ES 12 - I noticed you use different O-rings for R134 and R12. But ES 12 seems to be something completely different than R12.
 

MOGolf

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underneath something
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On the 98 Jetta follow the AC lines to the right front corner of the car.
 

ugetwhat

New member
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Apr 13, 2005
TDI
Golf GLS TDI, Red, 2001
Web site

Want to be sure I order the AC parts from the correct web site. What is complete path to Impex?

Thank you,
 

oj1111

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alabama
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2000 Jetta TDI
can anyone point out how to check the nut onthe input shaft on the compressor? someone told me to check that before replacing my compressor to make sure it was tight enough.
 

Raimieb

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ATHENS, GA
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2000 Golf GL, 1.9L TDI
Additions To Directions, Some Important And Helpful Notes

this edit pertains to an A4 ALH Golf TDI 2000
the receiver/dryer goes in welded side up (according to the one that I ordered, not down!)...different than thread states...
make sure to check as the bottom refrigerant line that attaches to your receiver/dryer has three holes needed and the top just two...
make note of the following links and see which is the tensioner for the serpentine belt from this diagram by mogolf....
http://forums.tdiclub.com/showthread.php?t=201453&highlight=serpentine+belt
http://forums.tdiclub.com/showpost.php?p=1178275&postcount=9
also, DO THE JOB RIGHT THE FIRST TIME, much easier if you have a shop evacuate the system down with vacuum and then vacuum for a while before recharging...ENSURE NO MOISTURE IN SYSTEM
make sure you drain existing oil out of your new compressor by turning it by hand upside down...then replace with about 4.4 oz of new oil (should be supplied by whoever you ordered your compressor from)...oil goes into the suction side hole of your compressor, you can give it a turn until it begins to come out the discharge side if you like to make sure it is lubricated well before installing...also, a shop can inject oil with the freon to make sure there is enough in your system...
note on a new compressor...got my kit from www.discountacparts.com
cost was 365$ shipped for compressor, expansion valve, and receiver/dryer, with all new o-rings for the entire system and oil...shipping was prompt and via ups...
any questions feel free to email me or send a pm...best, Walter
 

compu_85

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Springfield VA
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... None :S
Great write up! So, with the R12a you use PAG oil? I ask because I need to get the AC going again on my ECOdiesel, which was originally an R12 system. I have a new R134a expansion valve waiting to go in, new dryer, and a compressor from a car that had working AC when it was removed. The original expansion valve has been sitting with caps on the end of it for who knows how long (some PO removed all the AC lines under the hood) so I don't trust it.

How long would you let a compressor sit open on the shelf before you considered it junk?

Another source for parts is http://www.autohausaz.com/ They don't have the selection impex always does, but their site is easier to navigate and their prices are good.

-Jason
 
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hevster1

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Location
Columbia NJ
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98 NB
Congrats on trying.
You did it wrong.
The first thing i would do is recover the crap refrigerant you put in it and then flush the system with a solvent and compressed air. You want to do this with the evaporator disconnected and the receiver drier removed. Make sure the compressor is disconnected as well. I would also remove and flush the evaporator. The best thing to do is remove the condenser and flush as well. There are also inline filter screens made that you can use. After flushing drain the compressor of the contaminated pag oil and refill properly with the correct PAG oil. Replace the receiver/drier again(Last Step, you only have 10 minutes till it is useless) and evacuate the system for at least 1 hour. Then recharge using a decent gauge set which monitors both high and low side pressures.

Currently the system is airbound and cannot work to potential as well as there being moisture in system. The oil was filthy from the compressor failure and I am sure there is still crud in system. 21 degrees at the vent? Your thermometer is broken. The evaporator would turn into a block of ice. If your low side gauge is reading this your system isn't full.

If you chose to ignore my advice you will be replacing it all again in short order.

To those who think they know better flame away. Or better yet ask Oilhammer or one of the other respected technicians who do or did this for a living.
 
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MOGolf

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oj1111 said:
can anyone point out how to check the nut onthe input shaft on the compressor? someone told me to check that before replacing my compressor to make sure it was tight enough.
You need to counterhold the compressor clutch with tool 3212 (or equivalent pin wrench with 4mm pins) and tighten the nut to 11 ft-lbs (or if it is the compressor with a bolt tighten to 15 ft-lbs). It is supposed to be a self-locking nut. If loose it should be replaced rather just tightening it.
 

MAXRPM

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00 Jetta and 99.5 Golf, 2015 Passat TDI,BMW 2
Good info, I have to do mine
 

MAXRPM

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00 Jetta and 99.5 Golf, 2015 Passat TDI,BMW 2
I changed my A/C compressor about a year ago, and now when i put my A/C on for about 20 min, the A/C aluminum hose close to raditor gets forzen up,

Reading this post I found out that I did the job wrong, I did not replace the expansion valve and the drier, so i ordered them and I will be replacing them, and use that friendly Es12 refrigerant too, a friend of mine told me that I should replace the A/C filter too, never heard of an A/C filter before, do our TDI cars have A/C filters?


is there any other recomendation that you guys may want to share before I do the installation for the expansion valve and drier? I would like to do the job right,,, thanks
 
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Asl6

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May 29, 2008
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England
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02 passat tdi estate AVB PD100
hi all,i've got a problem with my air-con. basically the receiver/drier has worn a groove in one of the aircon pipes because the pipes have been pressed against the drier and so i have oil leaking out now,marvellous!
Anyway,i've been told i need a new pipe,obviously, also apparently i need a new drier,is this true? i'm not sure what refrigerant's in the system. i've been quoted a pretty steep price. cheers,aid.
 

Asl6

Member
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May 29, 2008
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England
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02 passat tdi estate AVB PD100
sorry should have posted vehicle details. 2002 passat tdi 100 horses.
 

hevster1

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Columbia NJ
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98 NB
Replace the pipe and drier. How much oil leaked out? If it is about an ounce or 2 get a can of PAG oil charge and use that first before you charge the system. It is very important that once you replace the drier and pipe to evacuate the system for at least 30-40 minutes preferably an hour or 2. You have only about 10-15 minutes of having the drier exposed to air before it is useless.

Someone has asked for the proper procedure.
1. Flush system if necessary with proper solvents. If you see tons of grit/metal from compressor damage keep flushing till clear. MAKE SURE there is no solvent or metal/grit trapped in the evaporator or condenser.
2. Replace defective components EXCEPT receiver/drier.
3. Replace receiver/drier. Do NOT pull the plugs out until ready to connect lines.
4. Evacuate system for at least 30-40 minutes.
5. Charge system with R134A.
It is your car so use whatever refrigerant makes you happy. Nothing but virgin r134a is recommended. Blends and hydrocarbons can be dangerous. But do what you want, not my problem.
 
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Asl6

Member
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May 29, 2008
Location
England
TDI
02 passat tdi estate AVB PD100
Hi hevster1, not sure how much oil has leaked out but it's been leaking now for probably about a week or so, i thought it was engine oil at first until last night when i had the car up on ramps to investigate and discovered it was the split air con pipe. i've booked the car in for the job doing but they can't do the job until late next week,in the meantime oil will continue to seap out!

thanks for listing the proper procedure. i'm a bit apprehensive as to whether they'll do the job right so i may just print this out and show them this,i'm sure they'll love me for it!!!
 

tdibigd

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2013 Passat TDI SE w/DSG, black on black
Nice job. I agree that evacuating the system would be ideal, but many DIY'ers don't and seem to get by just fine.

The only other point I'd mention is that the new compressor is pre-charged with oil (at least mine was), so the can of oil charge may be superfulous in some cases.

Very nice job.
 

hevster1

Vendor
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Nov 14, 2005
Location
Columbia NJ
TDI
98 NB
tdibigd said:
Nice job. I agree that evacuating the system would be ideal, but many DIY'ers don't and seem to get by just fine.

The only other point I'd mention is that the new compressor is pre-charged with oil (at least mine was), so the can of oil charge may be superfulous in some cases.

Very nice job.
But in ASL's case he isn't replacing the compressor. I will edit my post to say that if you replace the compressor adding oil is USUALLY not necessary. Some cars do require extra oil(Toyota Sequoia for one).

If you do not evacuate the system you may as well not replace the drier as a new one will be useless in no time. Also you will never get as cold or as efficient as a system which has been evacuated. Under certain conditions it may not even cool at all or very slightly. I know that some DIYers claim theirs work fine. My response is compared to what? Several years ago I had a Toyota Tercel which I installed an A/C system into. I connected the vacuum pump and went to lunch. Right after lunch I got side tracked and couldn't get back to that car for about 3 hours. It had the coldest, most consistent A/C in a Tercel I had ever seen. We were in a desert environment where daytime temps could exceed 120. Compared to most systems this tercel was amazing with vent temps in the low 70's with 120+ ambient. A good evac is important.
 

hevster1

Vendor
Joined
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Location
Columbia NJ
TDI
98 NB
Asl6 said:
Hi hevster1, not sure how much oil has leaked out but it's been leaking now for probably about a week or so, i thought it was engine oil at first until last night when i had the car up on ramps to investigate and discovered it was the split air con pipe. i've booked the car in for the job doing but they can't do the job until late next week,in the meantime oil will continue to seap out!

thanks for listing the proper procedure. i'm a bit apprehensive as to whether they'll do the job right so i may just print this out and show them this,i'm sure they'll love me for it!!!
I would add 2 oz of pag oil direct into the line before sealing the system up. It should not be poured into the drier.
 
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