DIY - Red Tek conversion

[rockfish]

I hope that this question doesn't hijack the thread - but I am wondering if any of the AC-fluent Samba-istas on this thread would recommend converting from r134 to Red Tek? The previous PO already made the initial conversion from r12. Of course, I'd be interested to know if there are any special precautions or procedures to take. From markz2004's list - what items do I delete, add or modify?

We all know that Vanagon/Westy AC stinks. I'm just trying to get the best possible performance.
_________________
89 Westy
GW 2.5 5-speed trans

"It's what you learn after you know it all that counts."
- John Wooden

[morymob]

have never converted r134 to RED-TEK but when i ordered mine i asked about this & they said it was 100% swappable-no seals or oil changes necessary just dont go mixing diff types of oils.

[Volksaholic]

[rockfish]

Thanks. Next question - I've gone through "search" and have learned that you only need 17oz. total (including proseal and stopleak if nec. 13oz RT, and 2oz per additives). I've noted the discussions on the high pressure reading being "too high" or at "r134 levels".

What should the Red Tek pressure readings be at both the low-end and the high-end? Are these readings Vanagon specific or mfg specific?
_________________
89 Westy
GW 2.5 5-speed trans

"It's what you learn after you know it all that counts."
- John Wooden

[markz2004]

Below are the recommended pressure amounts in my DIY step listing. I obtained these levels from prior Samba postings. In actuality I believe Terry Kay was the source for these recommended pressure levels. In a quick search on the Red-Tek website, I could not find a recommended "manufacturers" pressure.

At idle - 30psi low side, 200psi high side. At 1500rpms – 25psi low side, 200psi high side.

Terry - can you confirm / clarify?

thanks,
Mark
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87 Westy, 250k GW 2.4 - 2.0 , 16" wheels

[Terry Kay]

<<At idle - 30psi low side, 200psi high side. At 1500rpms – 25psi low side, 200psi high side.>>


Mark
28 to 30 is good at idle and WOT throttle.

At WOT the low side pressure will drop for a couple of seconds but will come back up to the fast idle number's pretty quick.

I try to keep the high side between 190--195 lbs.
200 won't hurt anything, I just prefer to keep them a bit lower for the old, crusty AC component's benifit.

Experiment with the pressure's, your system may work better with a little more--a little less juice.
Each and every one is different as far as operating presures and how much cold air you get out the vents.

Pretty much rule of thumb you have to establish a starting high & low side pressure--then work from there, lowering and adding pressure for the best optimum output temps.


Good Luck,
_________________
T.K.

[Terry Kay]

<< Are these readings Vanagon specific or mfg specific?>>

No.
The high and low pressure settings are pretty much automotive specific.

An automotive AC sysyem is an AC system.
Pressures are consistant with every vehicle on the road-
The only thing that will change this number is the type of refrigerant your using.
( ie; 134-A runs higher pressures
than R-12, R12-A)
_________________
T.K.

[pete000]

OK, no 134, I will order up the Red Tek tomorrow.

I will also drop the rear coils to give them a cleaning.

This thread sure is an AC learning experience...Thanks all for the info.
_________________
1990 Vanagon RS 2.1
1967 Deluxe 21 window
--------------------
Koni Shocks
H & R Red Springs
Addco Sway Bars Front-Rear
18 X 7.5 and 18 X 8 OEM Porsche Wheels
Recaro Power-Heated seats

[pete000]

Well I tried flushing out my AC lines. Here is how it went.

Checked my system to see if there was any R12 pressure, Empty no pressure.

Disconnected the compressor lines at the compressor.

Cleaned the seals and line ends.

Poured some of the AC flush in the low side line with a funnel.

Hit the line with my air compressor about 100 psi.

line was very resistant to flow the air almost not able to blow this direction. After a bit some vapors came through but no solution or oil or anything else.

Then I did the other line and blew through that line, more pressure went this way, but not much better flow. Again nothing but some vapors came through. no oil no fluid nothing.

I'm I doing this right ? does the engine have to be running?

Seems like more junk should have blown through.

I have not disconnected the receiver dryer yet.

Terry?
_________________
1990 Vanagon RS 2.1
1967 Deluxe 21 window
--------------------
Koni Shocks
H & R Red Springs
Addco Sway Bars Front-Rear
18 X 7.5 and 18 X 8 OEM Porsche Wheels
Recaro Power-Heated seats

[Terry Kay]

The fluid must go one way or the other---
Out of the low side line when blowing in the high side, out the high side when blowing in the low side.

If not---
Here's reasons.

(A) your evaporator is plugged up.
(B) your condensor is plugged up.
(C) your expansion valve is plugged up in the capillary tube.
(D) you have a plugged up dryer
(E) you have a collapsed line between the compressor to the evaporator or condensor.

The solvent must blow back at you at the compressor lines disconneted or you have some serious blockation.

The best thing you can do is when you have pressure at the open line at the compressor ( doesn't make any difference which) start cracking lines till you find a coupling that doesn't allow any fluid or air to come out.
Your plugged up behind that fitting .

This is a two man job.
One on the air hose pressurizing the compresor lines, one on the fittings with a wrench.

There is no other way to locate a plug in the system.
_________________
T.K.

[pete000]

Thanks Terry, I was afraid that was going to be the answer.

I did hear some burbling near the dryer when trying to push the fluid through in the high side fitting. I guess I will start at the dryer first.

I have a new dryer and hopefully it is the failed item. I did not see any pinched lines any where.
_________________
1990 Vanagon RS 2.1
1967 Deluxe 21 window
--------------------
Koni Shocks
H & R Red Springs
Addco Sway Bars Front-Rear
18 X 7.5 and 18 X 8 OEM Porsche Wheels
Recaro Power-Heated seats

[Alan Brase]

[Rodknock]

My '86 Westy was converted to R134 professionally a few years ago by the PO. I find that every summer I have to recharge it. So, a question for you Redtek users, will I still have to recharge it every summer assuming there are no leaks in my AC system?

[Volksaholic]

If your system is holding a charge through the summer I think it's safe to say that the RedTek recharge kit will cure its ills. The recharge kit includes a can of their LeakStop (or something like that) which is supposed to help seal up rubber hoses and o-rings. They also have a ProSeal product that can take care of tired rubber and other minor leaks. In either case, based on what I've read, R134 has a smaller molecule that leaks more readily. On top of that, it runs at higher pressures so a tired A/C system is more likely to leak.

I guess it's always possible that your system is in worse shape than what LeakStop or ProSeal can help, but if you have a pro shop evac (which you should do anyway) and ensure that it will hold a vacuum I think you'll be happy with a RedTek conversion. BTW; there are other Hydrocarbon refrigerants out there that I would think perform as well as RedTek. I went with RedTek because it was recommended here and it seems to work well in both my Subaru and the Vanagon.
_________________
1988 Wolfsburg Edition, 2001 Subaru EJ251

[Terry Kay]

<<I did hear some burbling near the dryer when trying to push the fluid through in the high side fitting. I guess I will start at the dryer first.>>

This is a good as any place to start--
However, cracking thie line on the compressor side of the dryer doesn't mean the line on the opposite side of it isn't collapsed.
It's gonna be a hunt and peck discovery mission.

<I have a new dryer and hopefully it is the failed item. >>
The dryer's just get plugged up with snot from years of absobing floating garbage in the system--the alcohol should have gone through it without too much problem.

Crack the line on the other side of it and see if you get the cleaning fluid through it first.

<<I did not see any pinched lines any where.>>

You won't.
The hoses collapse internally when they get old.
They have a liner inside of them that lets loose from the outside portion of the hose, and closes up on the flow.

The expansion valve has a tiny capillary tube inside of it that snot flowing in the lines will cause it to plug up.
This is another good plce to examine closely.
_________________
T.K.

[Terry Kay]

<<Pretty sure these numbers will increase with the outside temperature.>>
And with the humidity Al---

<<Typically, A/C designer aim for a certain drop in temp across the evaporator. Like 20 degrees,>>

If you can see a 20 degree drop in the ambient air temp at the vents at the evaporator core with the Van's rear hatch open , your doing real good.

Here's the biggest problem with the Vanagon AC stystem.
The damn front air intake & heater valve.
You've got the AC blasting and your flying down the road in 100 degree 99.9% humidity.
The front heater valve is half assed open a hair, the heater door seals are shot and leaking, and the rear AC unit is never going to be able to recirculate any cold air it's already cooled.
The interior of the Van isn't ever going to get cold -- enough to reuse & recool the air it's already chilled.
It's kinda a self defeating system.
This is why I made myself the front heater shut off valve--
I even take black duct tape and close off the front fresh air intake grill.

Now the heating system is absolutly shut off, and the AC unit will be able to keep up with itself.


<<Terry, do you think the air brake line stuff is just denatured (Methyl) alcohol?>>

Right off the top of my head Al, I don't know , and am not sure--but I'll take a look a a bottle of the stuff and report.
The only reason I first used it , the shop always has a case or two of the quart bottles of it laying around for the trucks in the winter---

I figured that if the stuff dries & keeps the air lines clean in a semi durring the winter, it ought to work good for flushing out the AC lines in an AC system.
It was an experiment 20 years ago, and it worked out real good.

<<hell, I've got a 55 nearly full of the stuff. Left over from mixing my own paint stripper. I'd love to sell it for $39/ quart. I'd love to sell it for less than that.>>

I think the air line anti freeze is about 6-7 bucks a quart.
I'd like to see some of this AC line flush that is $39 bucks a bottle--
It can't be nothing much more than what you have in that drum---
Another opportunist situation.
Put a label on it, and sell it for 4 times what it's worth--

Only in America--Land of Opportunity.--~ -

PUt a label on the drum Al--

Genunine Brase AC Line Cleaner & Conditioner"

Get a G note for the drum of the stuff---
_________________
T.K.

[Terry Kay]

<<My '86 Westy was converted to R134 professionally a few years ago by the PO. I find that every summer I have to recharge it. So, a question for you Redtek users, will I still have to recharge it every summer assuming there are no leaks in my AC system>>

The Red tek not only allegidly has a larger molecular structure , but runs at lower pressure's.
With the mile long hoses in your 22 year old Vanagon AC system, it sure would be a good idea to drop the operating pressure's.

Or--if you want to absolutlely want to eliminate any possible freon leaks, be prepared to change all of the hoses,seals, and fittings.

I think the Red Tek is the lesser of the two evils in this situation.

I'll tell you guys what this stuff was originally made for.
Farmer's & heavy construction equipment.

Tractor's and Cats with cabs & AC units have a mile long hose system too.
The ticket was to get the system to operate at a lower pressure so the hoses & fittings that were failing often due to the 134-A's higher
pressure would survive a summer's work AC season---

The Red Tek worked, and worked well.

I'm not going to say if you have a rock hole as big as your fist in the condensor, the stuff is going to cure that--
But I will say that it will last longer & stay in your system a bunch longer than the 134-A, and blow one hell of a lot colder that the 134 alternative.

The only problem with the stuff is isn't available at every Tom, Dick, & Harry's, local auto parts store.

So I just load up with a case or two of the stuff, and am good to go for a couple of years.
_________________
T.K.

[pete000]

Update:

I pulled the receiver dryer off today and was able to blow air up the front of the bus and exit at the compressor. (Front condensor and lines clear.)

I was able to blow air from the receiver dryer to the rear of the bus exit at the compressor. That line is clear.

I hooked up the new receiver dryer along with new seals.

Now from the compressor I can blow air through the line going to the front of the bus ( I think the High side) the air goes all the way and returns out the low side fitting at the compressor. All clear.

Now If I try to blow air through the low side It will not go. Seems to be only able to blow in one direction. Is this normal ? Seems that if there is a blockage it is at the rear condenser or the pressure regulator, but only on one direction.

Terry ?
_________________
1990 Vanagon RS 2.1
1967 Deluxe 21 window
--------------------
Koni Shocks
H & R Red Springs
Addco Sway Bars Front-Rear
18 X 7.5 and 18 X 8 OEM Porsche Wheels
Recaro Power-Heated seats

[Terry Kay]

You've figured out that in fact the dryer was plugged.

You've also found that more than likely the expansion valve capillary tube is plugged up too, as I think I had mentioned somewhere up above.

It's a tiny passage, will choke off in an old system that has plenty of junk floating around in it.
I've never seen, or experience an evaporator plug up--but anything is possible.

Your going to have to get up into the cabinet where the expansion valve is and remove it from the line.
You can try to clean it and blow it out--or replace it.
A common replacement item.

Now once you get everything open remove that new dryer and use a jumper tube to connect the lines at the dryer together.

I don't think I'd be blowing all the snot in the system through a perfectly clean & new dryer.
Whats that stuff Called Al--Dessecant? (sp?)
The dryer is full of these little air drying pills.
I don't think it would be a real neat idea to be loading them up with garbage before the system has been operational.

If there is enough garbage in that system, a hose could be coming apart internally and all the crap is floating around in the system--or all the stuff in there is just from old age and plugging up in the tightest spots.

I think if the dryer was plugged up--I'd be thinking of replacing all of the hoses too.

Or you can go pot luck , get it all cleaned out, and see what happens.
_________________
T.K.

[Alan Brase]