A/C compressors, lines, leaks, incl. 134a conversion


New member
Last June I brought the Westy in to the VW dealer because the a/c wasn't functioning.

They changed some resistors on the cooling fan and replaced the freon. The freon they put in ($250) has a dye that shows any leaks. 3 months later it wasn't cooling anymore. Since I had been out of town pretty often, by the time I was ready to bring the vehicle in it was too cool to bother with the A/C.

Brought it in last week. They wanted to put some more freon (at $250) to find the leak.

After I blew my stack and asked them how many times they plan to refill it before looking for the leak, they suddenly found the leak at the "H block".

$700 later the A/C was colder than a blast freezer. 8 hours later, nothing.

I'm bringing it back in the morning and leaving it there for a week. Any advice I should give to these experts? /infopop/emoticons/icon_mad.gif

[This message was edited by Capt. Mike on October 08, 2002 at 06:29 AM.]

Capt. Mike

Call VW headquarters and tell them you're taking the car in and want their rep ON SITE.

Remind them there is a VW warranty on parts & labor; and tell them you are posting their name, actions and results on this site with over quarter million hits & 400 readers a day!

Sometimes it's the squeeky wheel that gets the grease. And when the factory rep gets there, they usually decide all those things they should have found and done right the first time get done.

But . . . A/C systems are meant to be run for a few minutes EVERY WEEK. Yea, it's a pain to run the heater wide open and the A/C just so it cycles, but it reduces the amount of times there are leaks, keeps seals & everything else lubricated, and finds problems before so much time has elapsed the dealer can claim it's a 'new problem.'

Capt. Mike

Transferred from other posts to consolidate similar topics.

kosho Junior Member # 255 posted 08-08-2000 12:11 PM

What's "134a"? Was it used in any of the Vanagons/Westy's, or will I have to convert even if I find a 91 parts car?

Capt. Mike: R-134a is the type of freon currently used by most A/C systems. Production of old R-12 freon has been outlawed and it is only available to licensed A/C shops. As supplies dwindle, price is skyrocketing. The two are NOT compatible, but the systems can be changed over. You must completely evacuate, purge & flush the old system; change the receiver dryer; flush & change the compressor oil; and many recommend you change the seals & O-rings in the sytem. There are kits available, both good & lousy, but if you're installing a new system, it will be a lot easier because of access. To answer "kosho" since all freon will be lost when you break apart the old system, it doesn't really matter. None of the Vanagons were factory filled with R-134a.

Newer style A/C compressor on 79 Westy

Screamin' Jimmy Junior Member # 580 posted 02-01-2001 01:56 PM

Hi all,

The original (dealer installed?) York A/C compressor on my '79 Type II Westy gave out last summer and I am looking to upgrade it before summer hits again. I can have a rebuilt York installed locally for around $200, but I've been told that the newer style compressors are much more efficient. I've never seen one installed on a bus, so I need help to know where to start looking.

Although I need info on what compressor to look for, I'm more concerned about the mounting brackets. If I absolutely had to, I could fabricate whatever I need to make almost any compressor work. But I need to minimize down-time, so it would be most helpful if there were a supplier of off-the-shelf brackets to put a later compressor on my Type IV engine.

Have any of you ever done this? What compressor/brackets do you recommend?

Thanks in advance,

Capt. Mike Moderator Member # 11 posted 02-01-2001 11:12 PM

In '79 there was a factory air but it was rarely found on US bound models. The Cool-Aire supplied, factory authorized unit installed at dealers or POE was a superior unit. If your evaporator & fan unit is under dash, and the compressor fits into a cut out to the left of the engine, it was the US supplied unit.

I can't add any information on changing compressors, however. Sorry; I know I'd consider it myself along with conversion to R-134a. Not from an efficiency point-of-view, I don't think that's major, but for the smoothness of a rotary vs. a piston compressor and probably more reliability.

R134a conversion
dpender Junior Member # 759 posted 05-26-2001 02:44 PM

I recently found a pretty obvious leak in my AC system; the hose coming from the compressor is leaking at the fittings on both ends. Thought I would go ahead and replace all the hoses coming from the compressor and dryer, though there is no indication they are leaking.
My question is, is it worth the effort to go ahead and do an R134a conversion and does this conversion require replacement of the dryer?


Capt. Mike Moderator Member # 11 posted 05-27-2001 08:04 AM

Yes, and yes.

If the system has to be opened for any major repair, it is worth while to do the R-134a conversion. Just the difference in freon costs should justify it, and R-12 will only get worse.

Do consult with a professional A/C man over the conversion. There are shysters out there that will just change the compressor oil and freon and let it go at that. NOT the way to go. System must be purged, flushed and most recommend changing the seals & o-rings, too.

Second, the receiver-drier should be replaced any time the system is open for major work. It's a must for the conversion, but the cost for what is basically a consumable service item anyway doesn't justify opening the system back up later. Plus the possibility it could release some moisture and trash it's trapped over time back into the system. Old receiver-driers eventually lose their ability to trap moisture and you end up with more freeze-ups and related problems. However, they are generic so you don't have to go the VW OEM route as long as it fits. Get one with a sight glass.

What is the A/C Charging sequence?

jpquick Junior Member # 121 posted 06-21-2001 12:35 PM


85 WESTFALIA A/C R134a charging sequence.

Compressor oil? Does pag and ester mix.
Does the compressor oil stay in the compressor? Does it matter if the van is angled rear downward when charging or must it be on flat ground?

The Bently lists an 85 with a Sanden 508 compressor. Has there been a change in model#'s. I ordered a Sanden 510 listed for an 85 from VANAGAIN along with a receiver dryer. Hope it fits?

Any help appreciated.

Capt. Mike Moderator Member # 11 posted 06-21-2001 08:11 PM

A major change in converting from R12 to R134a is the oil. They are NOT compatible and the old system must be completely purged, cleaned and empty before adding the new. In fact most recommend changing ALL seals as the old ones will have been contaminated with R12's & its oil so may lead to failure of the system under $124a. The receiver-drier must be changed.
Although the system should be reasonable level during maintenance, the purge is done by vacuum so isn't that critical. Only a commercial purge vacuum pump will suffice. This is NOT a home job.

I don't know where you got your compressor info. My copy of the Bentley does NOT list any compressor suppliers as VW rarely discusses such matters in the Bentley. Consult your dealer for the official parts from the fiche. Although VW used a fairly generic compressor, it does NOT mean they were all the same nor are interchangeable. The usual differences are in clutch, fittings and arrangement.

jpquick Junior Member # 121 posted 06-27-2001 11:34 AM


Ccheck VIN# and Bentley to make sure you are buying the right compressor and receiver-dryer if needed. 85 Westy with Sanden 508 compressor pump, contrary to my Bentley's Sanden 510 listing. (A four hour complete and careful job including replacing the compressor and receiver dryer.)

I figured out the whole R134a Conversion.

First of course, make sure your system has been profesionally purged (including old R-12 oil) to keep the environment and law happy. My old compressor blew and so the R-12 escaped. I was told by a professional tech, "Hey, a person can't forsee everything, so that is why we now use R134a." I also self purged the system myself with a brake line vaccum pump. Don't do it yourself if you know there is R-12 in your system -- go to a professional shop to have it enviromentally safley evaccuated. Check Jiffy lube and see if they can get the old oil out. If not, pay other shyster prices to have it done.

Next for the do-it-yourselfer like me (I saved hundreds). Go down to Shuck's, Craigen, or Walmart and buy a complete R134 Retro Kit. approx. $39.99 ( contains 3 cans refrigerant (12 oz. each and oil charge with o-ring conditoner (11.5 OZ). Buy a fourth R-134a can (around $5.99 for a 12 oz. can) seperately to make a total of 48 oz. refrigerant.

Change Receiver Dryer with new (must do) and O-rings if needed (recommended). Follow the retro's simple instructions. Try to do it on flat ground. I did mine on a slight rear end downward angle toward my garage to veer off nosy neighbor's wondering if what you are doing is safe. I used white high pressure pipe sealent on my original O-rings to ensure a tight seal. I've also uses it for propane connctions-works great.

Carefully follow the Bentley's A/C capacity listings. I was told by an ASE parts pro from Schucks's to use 90% 134a for old R-12 refrigerant capacity. Do your own investigation to make sure this is right.

I used the whole 11.5 Oz. oil charge with O-ring sealent and did not overill system- works great. I also used a special lube shot for compressor (in a black plastic tube $5.99) from Shuck's claiming to lower A/C temp by ten degrees.

Results = 56° idle / 48° degree driving at 2,000 to 2,500 rpm for 8 minutes so far.

My New Sanden AC compressor w/clutch from VANAGAIN.com was $175-call to confirm price before you buy. Ken at VANAGAIN says this price is no longer available, but with stiff competition. Bus Depot lists it for $179. Bus Depot also lists on its web page that new A/C compressors start at $169.99. Call to avoid being unhappy. Ask for warranty -- I took a chance without finding any info. from VANAGAIN.com on its actaul site. My receiver-dryer was $45 -- from VANAGAIN.com -best price I found on the net.

Take your time to do it right.


[ 06-29-2001: Message edited by: Capt. Mike ]


New member
jpquick's 134a conversion for an 85 WESTY

I added 1 more 12 oz. 134a refrigerant and a 3.0z super cool booster.
My manual A/C guage reads 25-good

3,000 RPM for 10 minutes driving resulted
in a temp of
44 degrees-ripper

My total fill was 4.75 bottles R134a refrig. (12 oz. each),
3 oz. super cool booster, and a dose of cooler addtive for R134a conversions claiming to lower temp by 10 degrees.



New member

For the do it yourselfers',

R134a retrofit or R-12 vans out there.
I did a complete 134a retrofit on an 85 WESTFALIA as listed above.

I have learned of serious accidents if people
don't take this job seriously.

Identify your low pressure service valve(suction), and high pressure service valve(discharge).
MY 85 WESTFLAIA Sanden 508 compreesor pump listed suction, and disharge (out) on the pump by connections.

Buy an AC pressure checker from shucks', craigen, or wherever.

Always fill on the low pressure valve!!

Failure to do so can cost you your life.
I heard from a professional mechanic, a friend, that refrigerant bottles can explode in your face if you try to fill on the high side, DON'T Do it!!, Take your time and use your head. Take it to a professional if you have any doubt.

a concerned member,

Capt. Mike

Transferred from another post to consolidate same topics.

R134a conversion - partial do it yourself??

shannon Junior Member # 1497 posted 07-16-2001 12:44 AM

The A/C compressor on my 89 Westy died, the mechanic I've been to for years says blown seals, and about $1400 to replace compressor, dryer, O-rings, and convert to R134a freon. Is this about the average price? I think I could handle the compressor and dryer replacement myself, but am wondering what kind of effort I'm in for getting to all the O-rings? Is it more than just replacing O-rings at the end of each hose in the evaporator,condensor, compressor, and dryer? Would like to save some $$ by doing the parts replacement myself and having the mechanic finish the job, but will likely have no warranty on the repair if I go this route. Is it worth the risk?


New member
jpquick did the complete 134a conversion without replacing any o-rings
It would help if you have time to at least
replace the 0-rings at the compressor and receiver drier assuming there are no other leaks elsewhere in the system.

To make sure the system holds pressure-go to jiffy lube and have them do a pressure test=app. $50.

Capt. Mike

Transferred from another post to consolidate same topics.

A/C leak, new compressor

Torina Junior Member # 820 posted 07-19-2001 10:46 AM

1986 Westfalia camper: At purchase time 3 months ago we invested $700 for a new compressor and dryer/receiver at the suggestion of the "pre-purchase exam" VW mechanic in CA. (The a/c wasn't cold at all.) All was well for 2 months in CA. On a road trip when we hit Missouri (VERY humid), all went bad. After 2 hrs on the road, the car was stopped, and water was dripping INTO the car from the upper casing of the rear mounted A/C. We removed the side vents and blew through the drain tubing which didn't appear to be blocked. The car sat for 4 days in humidity. Drove it again and tried A/C with all windows up. Fan was fine, no dripping water this time, but no cool air. ARGH!!! A KS imports mechanic did a pressure check for $60 and said he can't find a leak. 1/2 lb of freon was left, compared to the full amount we had 2 mo. ago. He suggests a freon-dye test to find the leak for another $250. We've been thru this SOOO many times with a previous non-VW car and got nowhere (new leak in different spot every few months). Would it be wise to invest in replacement of all new tubing (essentially a completely new system) for reliability sake? What we don't want, is to fix one leak, then dye test every season to fix every other one that comes along. We also know there is warranty on our new compressor and dryer and wonder if the dye test would find a problem there, necessitating the cost of the test right away to get an answer within warranty time frame.

Lastly, our CA mechanic who did the compressor said that they don't use dye, only electronic sniffer for fear of dye coming inside the vehicle. When we have the car tested and fixed, shall we go the sniffer or the dye route? We plan to come home to CA before having it fixed, but what a miserable drive lies ahead!


Capt. Mike

Niether test is particularly effective. I use the sniffer, but it will give false readings when old freon pockets, or freon-laced oil is found. It will also go off from similar chemicals, including a propensity to go off around coolant leaks.

The dye test is effective but you have to be able to see it, which is difficult in a Vanagon with so much of the route & fittings hidden away. I wouldn't be so concerned with it getting into the interior as most of your leaks are confined to the outside routing or inside the evaporator housing, which has it's own drain tray and tubing. The amounts are not that much.

2½ lb. loss out of 3 in 2 months IS excessive. Vanagons are notorious for small leaks -- often just osmosis through the long lengths of hose -- so that a can a year is 'tolerable.' You have a 15 year old system and the natural aging of O-rings an hoses is bound to take its toll. This seems to be more appropos for Westies because they are often not driven for long periods and no matter how much we preach, most people WILL NOT run them for a few minutes every week to keep everything lubricated and sealed. Thus once they have begun to spring leaks, it's probably going to take many tries as the pressure from fixing one now blows the next weakest.

If your system shows such old-age symptoms that call for a resealing and perhaps some new hoses, then change to R134a at the same time. At least the freon won't cost your first born. Difference in freon costs alone can pay for a big chunk of it.


New member
Like most of us, I too have a leaky old AC system in my '87 westy. I have been following closely JPquicks reports of converting to R-134 and relaying the info to a local "expert". He claims there will be alot more heat produced at the compressor due to the relative inefficiency of the R-134 versus the old R-12. This will lead to premature failure, according to him.
My seasonal charging costs should drop as I have mostly eliminated the "chain" of leaks ( The darn P.O. never ever ran the AC.) but I still think the switch to R-134 could be inevitable.
What about this "increased heat" problem?

Capt. Mike

My personal opinion, over-rated. Although there are differences in the pressures and heat due to the natural differences in thermal efficiencies -- or what ever that fancy word is for a compound's ability to absorb and give up heat -- your system will still operate within the parameters of the compressor capacity and the pressure relief switches. Thus you will not have any higher top pressure. You may find some changes in the cycle rate of thermostats and coolant fan control switches, but not enough to keep with a freon that costs more per top-off can than the entire charge of 134a. I wouldn't change for the sake of it, but would at the next major component failure or opening of the system.


New member
Interchangeability of compressors
Can anyone speak to how interchangeable Vanagon compressors (or any A/C components for that matter) are? Specifically, my 90 Multivan's compressor suddenly started SCREEEECHING (it's not a belt...it's deep inside the compressor itself) and after a month or so of just not using it, it no longer produced any cool air at all. As far as I know, there's been no leakage. I'm looking at a working 84 compressor for cheap and am hoping for the miraculous successful swap-out cure-all. I know the lack of use has left me open to other problems, but I need a compressor regardless and I can't do any other troubleshooting until I have a functioning one.

[ 03-29-2002: Message edited by: lincoln ]

[ 03-29-2002: Message edited by: lincoln ]

Capt. Mike

You won't like this answer. If the compressor is shot, you will have to break the system to replace it, whether new or used. At this point you are up against EPA type regulations of discharging the freon and with your old R12 system the recharge will cost more than any compressor. Even the specialty A/C shops that can recycle R12 charge a huge amount for that privilege.

Thus you are at the point you might as well bite the bullet and convert to R134a, which has its own topic elsewhere on the site.

As to compressor interchangeability, besides physical mount compatibility, you have to compare pump capacity & pressure specs on the proposed replacement with those of your OE. Companies specializing in A/C rebuilds & equipment can best advise. I like Murray Gold Seal, whose products have been good and they have a tech hot-line. You may find a reman of your correct compressor a better investment -- now that you've already had to invest in the freon change expenses -- in the long run. You'd hate to have to lose all if the used compressor blows. Chances of an '84 being in top-notch shape are slim so I'd have to consider using one 'borrowed time'.

Capt. Mike

Junior Member posted June 17, 2002 05:46 PM

I have an 89 Westy with a TiiCo Jetta engine conversion and R134a A/C conversion. The A/C has been running well for the last 9 months. The van runs and starts normally until I shut it off with the A/C still running. It will then refuse to start, even with the A/C now turned off. It turns over and there is spark at the plugs. If I wait long enough, (several hours to a day), the engine will start normally again! Every trip I make to the mechanic, the problem disappears. I also seem to have a slow leak in the A/C, which has lost it's cooling capacity. Has anyone got an Idea for what is going on here? Any help would be appreciated.

Capt. Mike

It sounds like you are not getting equalization on the compressor and the engine is now being asked to start against the compressor's head pressure. Using pressure gauges, determine What your pressures are and at what conditions? For example, most home systems have a delay in case of power failure -- to prevent the compressor from trying to start agains full head pressure. Not usually found on automotive A/C.

There are a number of good books on A/C diagnosis for your A/C performance problems. I like Murray Gold Seal's. It gives normal ranges of readings for different systems and outside temp/relative humidy readings and a trouble-shooting chart. Confirm or remove the compressor from the possible problems by those tests.


New member
dI just had a new compressor and the conversion done by an A/C company--but somehow the housing over the belts at the back of the compressor was broken. He said it wouldn't hurt the system if it weren't replaced. Is that true?

Tim Hannink

New member
When I got my van, the belt guard was barely staying on. Its seems when they installed a new compressor, the belt guard wouldn't fit on properly, so they cut it up and tried to make it fit. I found a large cable tie and held the cover on with it, wrapping it around the compressor.

I swapped out A/C compressors last year and went to the dealer, got a new cover and it snapped right in place. I think it cost about $15.00.

You could probably run without it, but VW seemed to think it was a necessary part, I would trust them more than an A/C shop.

I think its primary purpose is to keep neckties and fingers from getting caught between the belt and pulley. A secondary purpose might be to keep the A/C pulley from contacting the underside of the engine cover directly.

Good luck,

TJ Hannink
Goldibox - 1987 Vanagon Camper, Wolfsburg Edition
Winter Park, Florida
http://photos.yahoo.com/tjhannink [Vanagon] Album

Capt. Mike

It's a safety part -- a belt guard. It works with a snap-in mode. It mounts at one end and snaps in the other; the wire tire is just to keep it from getting knocked loose and was put on at the factory -- at least the Austrian assembled units.

It serves TWO purposes: it hopefully keeps you from touching the moving belt & pulley, for example with a timing light or drop cord AND it prevents something from dropping in and perhaps displacing the belt.

An unfortunately side effect of VW's removing the sheet metal from the bottom of the engine when the switched to water-cooled was that stones can now fly up and twice I've had them catch the pulley just right and displace the belt. I've been lucky but I know of owners whose displaced belt tore up expensive cooling system bleeds, oil fill pipes, etc., before the engine got stopped.

Small price for a little piece of mind.


<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by jpquick:
jpquick's 134a conversion for an 85 WESTY

I added 1 more 12 oz. 134a refrigerant and a 3.0z super cool booster.
My manual A/C guage reads 25-good

3,000 RPM for 10 minutes driving resulted
in a temp of
44 degrees-ripper

My total fill was 4.75 bottles R134a refrig. (12 oz. each),
3 oz. super cool booster, and a dose of cooler addtive for R134a conversions claiming to lower temp by 10 degrees.

<HR></BLOCKQUOTE>Most people don't recomend using pipe dope (white sealant) on o-ring type fittings. While it may help with the seal, it is almost impossible to clean the threads on the connectionnut if you ever have to remove them. I don't know enough about a/c to comment on what would be an effective sealer in any is needed. Also I would never use pipe dope on flare fitting on the propane. In addition to the thread problem above, the sealant gets on the flare surface and makes it almost impossible to seal. A good flaring tool, and good fitting work well in almost every event. As far as I know pipe dope is only to be used on pipe thread type fittings Just my two cents, Icarus


New member
My 1987 Westy A/C started running warm, and the A/C guy tried to check the system but only found the suction service valve. The Sanden 507 compressor doesn't seem to have the high pressure Schrader valve. Is this normal, and how to check it? Thanks.