Recharge the AC on the cheap?

[blackglasspirate]

Hi all,

My AC worked when I first got the van back in 2006 and then the refrigerant leaked out. I did a half-ass job of fulling it with Redtek, as well as their proseal stuff. It doesn't blow cold now, so I'm sure it all leaked out.

Looking through all of the Redtek threads, it seems to be a pretty involved process to do everything right, and pretty costly. I mean, even just a A/C manifold gauge costs $60+ and I'd probably use it once.
I'm just wondering what's a good way to get the system functional without having to break the bank. I was just going to just get some redtek and possibly replace the receiver dryer.

Any advice? Unfortunately, I don't have much money to throw at this.
_________________
'87 Vanagon GL Westfalia
IG: @holidayatsee
FB: https://www.facebook.com/holidayatsee

[EvilDNA]

Unfortunately, it's a do it right or not at all kinda thing. You can get the gauge and compressor from a FLAPs for free (rental). Replace the necessary bits and clean the lines all per the REDTEK and AC threads. If you don't have to buy the gauges and compressor then it's not as costly as one might think. The thing about the Vanagon's AC system is that 'mostly sucks' . . . which means it doesn't 'all suck', unless of course, if the job isn't done properly and completely.

Do Change:
- Expansion Valve
- Receiver/Dryer
- O-rings

Clean/Flush ALL the lines (I did this in sections AFTER I pulled the EV, Evap Coil and Reciever/Dryer.) A tip I came up with was to fill the air hose with the AirBrake Dryer stuff, plug it into the compressor (HUGE EDIT: I meant to say compressor hose lines, i.e. high and low sides) and blow baby blow. No need to try to pour it into the various lines. Rinse/Repeat.

Reassemble and give a LONG time for testing the suck down. It's a closed loop system under pressure . . . shortcuts just end in failure.

Do or Do Not, There is No Try
_________________
1990 4 Speed Orly Blue Multivan

[blackglasspirate]

I actually just hooked up a cheapo pressure gauge that I had from before and it definitely says 0 psi. Some of the leftover Redtek stuff oozed out for a second.
One part I'm confused about is the whole "blow out the system" thing. How does one "blow out" the system? The two main reasons for not wanting to get to involved in it is 1) Money, and 2) I don't want to have to deal with taking out the rear cabinets to get to the evaporator and all the crap on the rear pillar. That stuff is a pain in the ass and I swore I'd never take it out again.

Either way, thanks for the advice. If anyone else has some input/experiences as well, I'd love to hear it.
_________________
'87 Vanagon GL Westfalia
IG: @holidayatsee
FB: https://www.facebook.com/holidayatsee

[blackglasspirate]

I just saw your edited post after I posted. I'm praying right now that the expansion valve isn't behind the cabinets (I don't have my bentley with me right now). Also, where are the O-Rings that need to be replaced?

Thanks again for the help.
_________________
'87 Vanagon GL Westfalia
IG: @holidayatsee
FB: https://www.facebook.com/holidayatsee

[EvilDNA]

The threads talk about an alcohol airbrake dryer liquid you can get for SUPER CHEAP at any Trucker Big Rig Supplier place. You want to use that to flush the ENTIRE system. You CAN flush the system as it is currently connected and cros your fingers that the Expansion Valve is ok. Flush from Hi to Low side and Low to High side. There is a ton of gunk in these old systems.

Then you can replace the receiver/dryer, connect and suck down to test, however, if you've got zero pressure, you've got a slow leak. Hence the need for complete disassemble and o ring replacement. Theoretically, the system, if it maintains complete seal, would never need to be recharged. You're leaking either from the O rings or the hoses themselves. That is going from cheap to expensive really quickly.
_________________
1990 4 Speed Orly Blue Multivan

[EvilDNA]

[pinealservo]

You shouldn't flush through the compressor, dryer, or expansion valve. The only one of those that's a problem is the expansion valve, since it's hooked on to the evaporator in the overhead cabinet. The dryer should be replaced when you open the system (fortunately they're pretty cheap) and the expansion valve is designed to be restrictive, so it could easily be blocked if there's any crud in the system.

However, if you don't have the cash for a major AC service right now, and the only problem is that the Redtek leaked out over the course of a season or two, then you're probably fine just sucking the system down with a borrowed pump and recharging it. It'll leak again, but it may be leaking through the old hoses, and replacing those is costly and labor intensive. AC systems need to be finely tuned to work really well, and the Vanagon system was marginal to begin with, so don't expect miracles with a cheap recharge.

[vanjoe]

I am retrofiting mine to R134a. Its as simple as removing the compressor and draining the oil. Replace all the o-rings and reciever drier. You can rent a vaccuum pump from FLAPS. And buy the retrofit kit which has the oil and refrigerant. I wouldn't go through the headache of changing the expansion valve. As long as you get as much of the old oil out and it holds a good vaccuum you should be able to charge it and have a nice running system.
_________________
1990 VW Vanagon tin top weekender Carat
1998 Mercedes S420

"Why is there never time to do it right the first time, but there is always time to do it twice?"

"Back to the basics!"

[Terry Kay]

<<<You shouldn't flush through the compressor, dryer, or expansion valve. >>>

1/3rd correct.
The expasion valve is one of the biggest offender's in poor AC performance, and if you want to try and clean it out, it will be to your benifit.
Blow from the low side to the high side first---do it twice to make sure you get any blockage outa there.
Then back blow it though the high side hose.
Never run the alcohol wash through the compressor.
The dryer washed out will not only get the snot out of there--but dry up the dessicant material.
No harm in giving it a wash out.
IT won't be as good as a new one, but will sure perform much better than a plugged up snotty one.


New O-rings--
This will require you to break every fitting in the system, and replace all of the o-rings there.
Front to rear.
Dropping the evap cabinet & the D pillar cover ( or closet ) is part of this process.
If you skip anythig--don't be suprised if your labors are fruitless.

I'd suck the leaking system down--see how long it holds the vacuum--and if it doesn't, it's time for a can of freon, and a sniffer.
Or a can of flourescent dye & a black light to locate the area of escape.

It's a time consuming process.
Be prepared to buy the proper tools to get the system tight, up & running or pay somebody that's got the right stuff to do so.

There is all kids of DIY AC info parked here in the forums--do some reading and get a better grasp of what's involved before you jump into this project.
I'm not sure what your parrameter's of "on the cheap" is, but I will say that shortcutting the AC job will give you pretty much the same end results.

Little in--A Little out.
_________________
T.K.

[pinealservo]

Well, I'm 1/3 correct according to the Terry Kay technique, I guess, which to his credit has proved successful in Vanagons and whatever other vehicles he's serviced with it. I'm 3/3 correct based on the recommendations of other auto air conditioning professionals and service guides I've found in my research, I didn't just pull those out of thin air.

I completely overhauled my system last year. New parallel flow condenser, new barrier hose lines, new dryer, new expansion valve. It's the huge lengths of hose and the fittings for them that were the major expense and the majority of the effort. Dryers and expansions valves are cheap, I got mine for $15 and $20 respectively. The nice thing is that the only thing I had to worry about flushing was the evaporator, and it wasn't terribly sludgy to begin with. As far as I'm concerned, having nice cool air blowing on me on long road trips was worth all the effort.

[EvilDNA]

I agree, basic AC rehab is relatively inexpensive, as long as the hoses, compressor, evap and condenser coils are ok. Replacing the expansion valve, receiver/dryer and o-rings are all basic expendables. And since you are replacing those bits, flushing out each section of hose is the simplest option. I never understood flushing the whole thing in series when you should be replacing those items anyway. New hoses though . . . would be nice to eliminate that 20-30 year old weak link.
_________________
1990 4 Speed Orly Blue Multivan

[Terry Kay]

<<I agree, basic AC rehab is relatively inexpensive, as long as the hoses, compressor, evap and condenser coils are ok.>>

And heres' the small, miniscule, isignificant problem.
20-30 year old AC components can't be all OK and up to snuff.
And if your changing one component, you best be doing it all.
Tossing in a compressor without changing everythig else in an antique system is a pretty lame idea and a temporary crutch at best.

<<And since you are replacing those bits, flushing out each section of hose is the simplest option.>>

I don't undertsand this one.
Flush out the section of old delapitated hose only?
Don't bother--replace it.

<<I never understood flushing the whole thing in series when you should be replacing those items anyway.>>

Being a newly self ordained AC aficinato you should know this answer right off the top of your head.

Compressor's are not oil & condensation tight .
With time the tapioca oil & H2O mix will foul the lines, component's & fittings.
It's the nature of the beast--especially if the lines have been open anywhere--and this does include any pin holes.

The crap must be removed for optimum operation, or your just playing with yourself.

<<New hoses though . . . would be nice to eliminate that 20-30 year old weak link.>>

There's more weak links in an antique system than just the rubber hoses.
Every fitting, o-ring & the heart of the system is weak.

This is why I came up with the Red Tek advisory a few years back.
Lower operating pressure's, the possibility of survival of of the old stuff is a bunch greater than converting to 134-A and blowing parts sky high.

Pretty elementary, and the reasoning is simple to the AC system flushing proceedure, & the use of the Red Tek.

But you knew this.
_________________
T.K.

[blackglasspirate]

Thanks for all of the expert advice. I don't want to drop the entire evap cabinet and rear cabinets to get to everything up there. At least, not right now. I've got too many other things to worry about. I'd just like to get the system running at least moderately well, if possible, without doing a complete overhaul. I made it the past 2 Tennessee summers without it and although it was miserable, I still lived.

What I'd like to do is maybe just get some redtek, blow out the system, replace the receiver/dryer and see if it will get me by for now. Replacing all of the O-rings too sounds like quite the undertaking.

By the way, where are both the lo and high pressure valves? There's one right next to the condenser, but I wasn't sure where the other was.
_________________
'87 Vanagon GL Westfalia
IG: @holidayatsee
FB: https://www.facebook.com/holidayatsee

[Terry Kay]

The high side port is under the D pillar plastic cover.

If you just want to clean her out and go--you'd be doing yourself a big favor by at least sucking her down for about a hour to get all of the moisture outa the sytem--then charge it up with the Red-Tek.

You'll get more cool outa the vents for as long as the freon remains in the system.
Be well worth the effort.
_________________
T.K.

[pinealservo]

You weren't clear in your initial post on how fast your RedTek leaked out before. But if it leaked out before, a system flush won't magically make it stop leaking. Fixing leaks is time consuming and potentially very expensive, and if your refrigerant all leaks out in a day or two, there's no point in even trying to get it to work now given your constraints.

My recommendation is to replace your dryer (it's cheap and easy to get to) and do a vacuum test with a borrowed vacuum pump and gauges. If vacuum holds overnight, charge it up with RedTek, or flush and then charge, but if you're going to flush through the dryer, don't install the new one until after you flush through it. If it doesn't hold vacuum, just return the equipment and leave the AC off until you get the funds to do it right, as you'll just be wasting time and money by charging or flushing right now.

[EvilDNA]

I have a feeling that, given the leak you have, after you spend the money to do what you've just described, taking into account time and money for this summer and the next (assuming it lasts a full summer), you'll have spent twice the cost of a properly done DIY job. The O-Rings are VERY easy to replace, especially since your system is already at zero psi and you mention replacing the receiver/dryer. At the very least, I'd add that to your list of half way measures. Could very well solve your leak problems. The suck down will really help you know if it even stands a chance . . . and TK is certainly right about getting out all the moisture/air. Do what you can, suck it down and see if it holds vacuum.
_________________
1990 4 Speed Orly Blue Multivan

[Terry Kay]

If you do plan on doing any flushing--& replacing the old dryer
It would be a real good idea to remove the old dryer, splice a piece of pipe or hose in it's place first,then flush out the system, and then install the new dryer.

There is absolutey no sence to be moving the oily garbage inside that old dryer aroud inside of the lines--then changing to the new dryer.

Its self a self defeating program---

If your not changing the dryer-- blow the alcohol through the system--both ways, evac, & charge.

It'll get some of the snot outa there, and if for nothing else, clean & dry out the dessicant pellets in there.
It'll work better than it did before ---
_________________
T.K.

[pinealservo]

I've always been a bit skeptical of your suggestion to flush the dryer, Terry, so I just did a bit of research. I'm fairly sure you can't dry silica desiccant with ethanol, because silica desiccant is used industrially to remove water from ethanol! Water only travels one way between the two substances, and that's the wrong way to produce a drying effect on the desiccant.

However, you can drive the water out of silica gel by applying heat. Baking silica gel in an oven at 250 degrees F. for a few hours will dry it right out and render it fresh for reuse. I seem to recall you mocking someone before for doing that with their dryer.

So, if you really wanted to reuse a dryer, you could probably clean it well by flushing it thoroughly with a solvent like ethanol, then heating it to 250 and holding it there until all the water escapes from the silica and evaporates. I wouldn't try it, though, unless you're absolutely sure you've got all the volatile solvent vapor out before you try baking it. You would probably also want to be sure that there's no components (i.e., some form of thermoplastic separator or something) inside the dryer that would melt at 250.

And anyway, they're cheap. Just buy a new one. Don't flush through one you intend to reuse (any dissolved water in the flush will be absorbed by the silica), and certainly don't flush with a new dryer in place.

[7thing3]

I started out last fall trying to do it as cheaply as possible. I was just going to blow things out, replace o-rings, replace oil, recharge, etc. When I disconnected the line from the receiver/dryer to the condensor it stripped, which meant I needed a new (used) condensor and a new line. I decided while I had it all apart why not do it right. So I had new hoses made to the tune of $260, put in new receiver/dryer and new expansion valve after flushing everything as much as I could.

I vacuumed it out for about 3 hours.

Just got it back together about a month ago and finally have some weather in which I can test it. I am running under 200 psi on the high side and around 25-30 on the low side at 2,000 rpms. Makes cold air but still haven't had that 90 degree high humidity day when it will really show its mettle.

I used RedTek. I basically used 3 cans plus some RedTek leak stop and some RedTek air dryer product.

I guess the moral of the story is it is a typical can of worms on a 25 year old car. I'm glad I took the extra time and money to do it right rather than having to do it a 2nd time (Well I sort of had to do it a 2nd time as I had to drop the evaporator unit as I was dripping water down the interior side panel. I used hose clamps on the drain hoses this time--note to others--do the same the 1st time)

_________________
'73 Thing--Ted
'77 Super Beetle Convertible
'87 Vanagon GL Syncro
'84 Mercedes 280 CE

[EvilDNA]