AC Expansion valve and insulation

[bobbyblack]

There are a few things to consider, just blowing through it might have you thinking one thing when it is not. For instance, I don't think you can blow 180 Lbs of pressure with your mouth...

Here is the rundown on things to do:

Get a new drier.

Get a seals kit

Take the hoses off the compressor, and remove the old drier. Also remove the expansion valve again.

Get a product used in the trucking industry called air brake line cleaner, most trucks stops have gallons of it on the shelf.

Run the brake line cleaner through the hoses out of the compressor by filling them up with some, you'll have to devise your own method of getting some in those hoses, then blow them out with compressed air. You will either get the brake line cleaner to flow through the hoses, or you will locate which component is the actual cause of your issue fairly directly.

When the piece or pieces of the system are replaced that were clogged, you are about half way.

Get that compressor off the engine, and dump out all the oil, check it over by eye, etc to be mostly certain it is going to actually work when you reinstall it, and fill with the proper amount of lubricant.

Reassemble the rest of the system, including the new direr, and new seals. Vacuum pump the system down and be sure it does not have leaks, then fill it with refrigerant of choice. I would suggest NOT using R134A, the Vanagon system just is not built for the pressures that stuff takes. The following link is to a product that is really a very close match for R12 (trademarked 'Freon'), in the pressure range, etc, and my system only takes 2.5 cans to fill (1987 Westy), so a case, even with a small leak somewhere, will last you a lot of years.

https://www.ebay.com/itm/355769228027?_skw=134a+re...BMhoOu94Zm
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'87 Westy 'Flossie','86 Westy 'R1','86 tintop GL - Subi2.2 'J2','83.5 stock tintop L 'ZoomBus','74 Karmann Ghia, '63 Notch

[vwmaniaman]

I had expansion valve problems on my 86 Westy. Got a chargeable canister from Advance Auto and loaded it up with alcohol brake like cleaner for diesel trucks. Shot that stuff through all the hoses and you would not believe the black snot that came out. Put a new dryer on and vacuumed and recharged with 4 cans of Red Tek. worked better than ever for 3 years. Be aware that the vibration of the waterboxer makes the fittings loosen on the compressor.
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Working on a VW is like fun with a friend!
65 Beetle
75 Westy "Pumpkin Van"
86 Westy "Brown Betty"
87 Cabrio

[khughes]

Stop Leak = Kiss of Death, like using Permatex on carburetor gaskets. It's just a slower death.

If your pressures do not equalize to within a few pounds, within a few minutes of stopping the compressor, then:

1. There is a blockage in the system - it will be the drier and/or TXV 99% of the time (unless the system was left open for some time).
2. Your gauges are junk.

One crucial thing I don't see addressed is - who converted it to R134A? And did they change ALL the hoses or TOTALLY flush the system to remove all traces of mineral oil? R12 systems use mineral oil, R134A uses either PAG or POE synthetics. Neither the 134A or the synthetics are compatible with mineral oil. If the system is filled with old now-congealed/waxy mineral oil, your expansion valve becomes a filter for the gunk in the system. The compressor won't be happy with that situation either.

It's your dime, and your labor, but for me I would cry uncle and just start over. It'll be faster and cheaper by the time you're done, and it should work correctly (which isn't *that* great to start with). Evacuate the system, flush everything (TXV and drier replaced, not flushed), drain the compressor to remove any oil, then dry system and reassemble all but the drier. Fill with the compressor with the spec'd amount of oil (PAG is preferable with new hoses, but POE is more compatible with trace residuals of mineral oil), put remaining system spec'd amount of oil in the new drier and install it, evacuate system and recharge. Personally, I'd replace the lines with barrier hose since the originals will be in bad shape after 40 years, and they will allow R134A to permeate the hose and leak. It's a PITA, like most things Vanagon, but its one and done.
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'86 Westy FAS GenV Turbo (Marvin)

[sikamore]

I am not sure what was done when the system was converted to R-134. The only evidence I have seen is that the expansion valve had a sticker that said R-134. Since I have already replaced high side hoses, drier and valve, flushed the evaporator already I will go ahead and replace low side hoses. I see that GoWesty has a "High Efficiency Condenser " Does anyone have any experience with this condenser ? Is it worth replacing? There I a YouTube of the installation and it looks like a PIA.

thanks

[khughes]

[dhaavers]

The GW parallel flow condenser is definitely an upgrade. I also installed the (essentially identical) Nostalgic Air unit and it works just like you’d like. I had no choice, my condenser was corroded and leaking from exposure to road salt…

IIRC, install is marginally easier on your early system… I know I didn’t need to drop the radiator. I think I’ve seen info on that with the GW instructions.

Glad to hear you’re finally springing for new low side hoses, but sorry to say, leaving them in place this long means you’ve basically contaminated all your new work with the old snotty oil that was coating the original low side hoses. Now your job is to treat it like a dirty old system, flush everything out again, drain and replace all the oil again, replace the TXV and receiver/dryer again, vacuum down again, and recharge . . . again.

Cold air is possible, you can do this! You’re learning as you go, like a lot of us around here. It also took me a couple tries, but 10 years ago I finally did everything right & I’ve had cold air ever since without any need for recharging. Keep on it, do it right and you’ll love the result.

- Dave
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86 White Wolfsburg Westy Weekender
"The WonderVan"
<EDITED TO PROTECT INNOCENT PIXELS>

[sikamore]

thanks for the encouragement. I am hoping that I can remove low pressure hoses without snipping off ends. There is a helpful YouTube that shows ends being removed for hoses to pass through chassis. If this case I am not sure how I will get the new hoses and fittings re-installed.

[4Gears4Tires]

You can remove all the lines without cutting the fittings off. Sometimes it's very annoying, but it can be done.
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'87 Syncro Ferric Oxyhydroxide Superleggera Edition
'85 Westy Sciuridae Domus Edition

[dhaavers]

[sikamore]

I replaced condenser and have removed hoses ( I am not looking forward to re-installing hoses! ) There was a lot of oily substance in hoses, is this PAG or decades of stop leak? When I vaccumed the system the same substance came out. I estimate there was at least 8 oz.

[vanis13]

[sikamore]

In the never ending AC saga, my rear AC fan on my 1986 Westfalia Syncro crapped out. I am not getting voltage so I assume a fuse is blown. I checked the fuses that have been identified as possible fuses # 1 , #12, #17 , # 18.. these are all fuse location that my research has turned up. There appears to be a relay and maybe this is an issue. Before I drop the fuse box I am curious if anyone know location for AC evaporator fan?

[Howesight]

The fuse and relay panel for the evaporator fans is located in the D-pillar area, not up front where the main vehicle fuse panel is. There are relays and also a 50 amp fusible link that blows when the current draw is too high - - as can happen with old blower fans needing lubrication or replacement.

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'86 Syncro Westy SVX

[sikamore]

I don't think so for an '86? I replace the high pressure hoses and didn't see a relay. Perhaps I missed it but from what I have read that old style ( pre 86 ) does not have same schematic .

[Abscate]

Just a note on PAG oil. You won’t remove it under vacuum, its vapour pressure is too low. Add on a new install or on a component basis, there are threads here on how much to add for new compressor, drier, evaporator, etc.
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[4Gears4Tires]

[dhaavers]

Sorry Howiesight, although your post is correct for late (mid-86 through 91) systems, it does NOT apply to sikamore’s early (pre-86) system…

[dhaavers]