Charging Air Conditioning System

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Originally Posted by timsrv

Based on what you said, at this point I would have very little confidence in that shop & certainly would not trust their latest diagnosis. If you cannot do this yourself, I'd be looking for another shop to take it to. If you do indeed have a bad condenser, I would keep an eye out for salvage yard parts and/or "parting-out" posts on craigslist. Good luck. Tim

PS: Depending on where the condenser leak is, it may be reparable. Did they pinpoint the leak? Leaks are usually identified by putting dye into the system, then the leak(s) will usually become easy to spot. Tim

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Since these guys got the AC working last summer for what seemed like a reasonable price and the fact that they have done other work that I was happy with, I have been giving them the benefit of the doubt. They haven't charged me beyond the initial repair and they have put a fair amount of time into it, so I don't question their honesty, but I have come to the conclusion that AC isn't their strong point. They did say that dye was used to determine that the the condenser is leaking. AC work is where I draw the line for DIY car repairs, so I guess I'm going to keep looking for someone to fix this for me or sweat out the next few weeks and just keep living without AC.
r
As for the condenser, would the one from my 86 2wd with front and rear AC work in the 87 4wd? From the notes on parts shown on Rock Auto (not available) it seems that a 4wd condenser would be different.

If both vans are there, get underneath and measure/compare. I'm guessing the 2wd has 2 condensers (both smaller) one vertical in front of the radiator and the other horizontal under the front. The 4wd probably only has 1 bigger horizontal one under the front. Tim

While overhauling my engine I decided to chuck the old AC compressor and go for a new one. The old one was making some rattling sounds and had 300K on it.
So the shop installed a new compressor and dryer. Evac the system converted to 134 and charged it up. Not real cold. I would say cool when at mid 80's outside. Being in Florida I need this thing to get cold. Am I dreaming here and this will never get cold? The guy told me that the 134 in these older systems is not as good as the R12 and will not provide the kind of cooling it was designed for. Wish I knew that before. So is the the deal or is there something we are missing to get this thing to at least be able to cool enough so I don't have to sit in sweat.

I insulated the engine covers with Dynamite Hood shield. Man that stuff works great. I would recommend it. The engine cover that was super hot is not room temp.

But still not enough to recover the ac.

I guess I will measure the cold output to see where it is. I know this is stupid since the air going in will be proportional to the air coming out but I can at least compare to other vehicles.

He did tell me to use both the front and the back systems all the time. That using both has little effect on the temp level. I did this but the rear one keeps blowing the CB. Schematic calls for a 30 AMP CB but the van only has 20 Amps installed. They look original. Anybody know?

MT

I hate AC issues and am far from an expert but here's the little I do know

R12 is significantly more efficient, as a coolant, than R134.
Systems designed to run on R134 are designed to work efficiently with that freon. (changes to evaporators, condensers and compressors to name a few)
An R12 system thats been converted, has to work harder (compressor cycles more frequently).
The lubricating oil (PAG) is not compatible between the 2 freons and the R134 PAG oil will eat R12 o-rings.
The habit when converting, is to only replace o-rings that get disturbed.
I assume proper procedures were followed for replacing the compressor?
System needs to be vacuumed, compressor drained, correct PAG oil measured and added among a host of other things.

The actual R134 molecule is much smaller than the R12 molecule, as a result, converted systems often develop leaks soon after a conversion.
(Its a bit like running 0W30 oil in an engine designed to run on 20W50)

Even the best conversions won't be as cool as the original freon, IIRC we were getting vent temps about 5-10*F warmer than R12 specs.
Converted systems are also very intolerant of any deficiency, everything has to be working at its best.
When we first started doing them we had a lot of expansion valve failures and quickly got into the habit of just replacing them as a matter of course.
(fewer headaches and happier customers)
The expansion valve is located at each evaporator.

An AC tech that knows his stuff should be able to figure it all out but those guys seem pretty rare.
I would be tempted to replace both Exp valves, refill and retest function.

If you find that even with everything dialled in, cooling is still insufficient there is one other option but it's not for the faint of heart.

There is a product out there, the one I am familiar with is RedTek but there are others.
Essentially it is propane with a strong pine scent added, that way if you ever do spring a leak, you will know right away.

RT is as, if not more efficient, than R12 as a refrigerant and it won't be as prone to leaks and will provide full system performance.
I was skeptical in the beginning probably due to a bad propane BBQ experience when young, but then I looked into the flammability of R134 and realized that while it has a higher flashpoint it is not without issue and if it does leak, you can't smell it.
Propane is also heavier than air so a leak should just dissipate into the atmosphere below the vehicle.
I have never found an AC shop that will condone its use.

My personal experience was on our Jag several years ago, system had been condemned due to leaks and sucked dry and the estimate was north of $2K to resurrect.
As I had nothing to lose I felt it was worth the test drive and for $100 the system was back up and running in an afternoon with no hard parts replaced.
System was still running cold when we sold it 2 yrs later. YMMV
BB

Wow! Well the guy that did the work seems to know his stuff but is very conservative in his actions. He goes by the numbers for sure. Your suggestion to rebuild the engine was the best move I made and I thank you for that. Plus I learned a ton about the process. I was able to be involved with every aspect of the process. Man, tons of fun.
So when he was re-installing the engine he asked about the compressor issue. He suggested to splurge and get a new compressor since it had this chatter and 300K on it. So I did. He would not even think about going back to R12. It was a 134 conversion.

He did all the things you mentioned, even the O rings. But it just does not get real cold. By July it will be hotter than hell here and it will never recover at the rate it cools now.

So if I decide to go the RedTek product type is it another evac, dryer, O rings and compressor oil again?

I really doubt he would do it. But I have a friend that can evac it and I can put in the freon replacement.

I would just have to find a few pounds of the stuff.

Any input is always appreciated.
BTW, any thoughts on my Circuit Breaker value question?
I looked again today and verified that the service manual calls for a 30 amp breaker and not a 20 which is in there.

Thanks Again for your input BB

Glad to hear the engine experience worked out well.

As to the CB, if the manual calls for a 30A I would change out the 20A to proper spec and see how it goes, I would not exceed the original spec though.

RedTek and equivalent brands are available at most autoparts retailers, up here CTC, UAP and a host of other places.
Shouldn't be hard to find if you decide to go that route.
As far as changing over, it only needs to be sucked dry, RT is compatible with both PAG oils.
One more consideration, going the RT route will likely void any warranties on parts and labour so you may need to consider that aspect too.

I would want to make sure that the system is operating as efficiently as possible and if either exp valve is compromised, the RT won't solve that.
You may want to talk to your guy and see if he feels there would be any merit in replacing them or perhaps he already has?

Wow, thanks BB. For sure the X valves have not been replaced. I will get those done and proceed.

The RT, or what is propane and butane, seems to work pretty well in either system and with both oils. It's cheap and when I put it in, it pumps out pretty cold. My system was empty when i charged it, and I was using a new compressor, but I didn't change anything else. I just added some oil. My friend used it to top off his system and used it with R134 already in the system, and said they would work together fine. He works in the AC field, for a company that does AC system installations in camper trailers, and it seems to still be working in his car just fine after a year.

Still working on getting my air up and running. Now, after the engine has been rebuilt with a new compressor it has not been able to hold R134. They have refilled 3 times already and claim they cannot find the leak. They already replaced the o rings but nothing has been done in the evaporator cases.

By a stroke of luck I found a small shop that only works on Toyota's. I went to see him and he knew our van, in fact he own 2 of them. I told him the story and he told me that since they did not find any die leakage in the obvious spots it is most like in one or both evaporators. I asked him if he could service it and he told me that the parts are questionable. He claimed that even Rock Auto parts don't fit and you don't know it till you get them and put them in. He will not make shift it. It has to be the right fit or he will walk away.

Does anyone know where I can get the correct evaporators for my 1986 LE 2.2 van???

I will assume the worse in that both front and back may need replacing.

Any help would be so much appreciated. I am in Florida and I am cooking like a hamburger in my seat.

I already laid in Dyomat hood insulating material for both the seat engine cover and the extended cover also. This has reduced the heat substantially. With so much glass in our vans the AC is the thing left to get reasonably comfortable.

Thank all of you in advance

MT

This is exactly why I hate AC system revivals.

That being said, if they put dye in, in HAS to be going somewhere.
Even if one or both of the evap's are leaking, even if hidden deep within, you'd think there would be some detectable evidence.
Are they leak checking with just a black-light or are they using a sniffer too?
Sniffers are really good at finding leaks in Evap's.

How fast does the freon leak out, like a day or a month?
Sealants(stop leak) are available and may be an option, but will depend on the severity of the leak.
Not too mention that stopleak after an expensive repair just doesn't seem right but...

I just replaced my front expansion valve and still not getting any cool air in the front. I’m about to give up and let a shop handle it because AC systems are beyond my knowledge. None of the lines are clogged, my blower motor and evaporator are fine. I really don’t know what would be preventing the front from not producing any cool air.

Hey BB!

It was leaking out of the system in a few days. So I finally brought it to another AC guy that seemed to have his act together. He filled it back up with 134 and die and found no leakes anywhere. He knew it would come back so we just waited. I took it and it worked as well as it will ever with 134 but failed again in 4 days. But now all that die came out and he found it coming out of the new compressor. It was leaking with drips coming off the bolts.

So, since the compressor is under warranty a new one will be delivered, maybe tomorrow, and this new guy will install.

But I have learned a lot about the AC system it self. There is a bunch of plumbing but due to the twin system but that is understandable. It is actually pretty easy to work on with both evaporators being readily accessible and all the plumbing under neath. But I agree, this is for AC guys. Maybe we can charge with cans but that is about the limit.

Will keep you posted on the results.

MT

Thats great news.
Fingers crossed that the new compressor solves all the issues.
BB

OK, the new compressor is in. Blowing cold but sure would like more. May go the TekRed route after I know this leak is over.

Will keep you advised.

Got another issue with Transmission. Have not found Jack on this issue in TVT, will start a new thread.

Thanks again BB

MT

just topped off with redtek. after 1.5 - 2 years AC had gone from cold to slightly cool air. added one can and it's blowing cold again.

one question: while charging i was getting about 38 - 40 psi on the low pressure side and i think tim said the correct range was 21 - 28psi?

i might have a faulty gauge ? but it's working well for now but if anyone has feedback please let me know

here's a photo while charging: the gauge has several color coded ranges for R134A, R12 etc

*also has a highlighted optimal area or 65 - 80psi?

Attachment 7203

Fantastic!
I had another set back with compressor turning off due to low pressure. This I thought was solved with a new compressor. It did least get almost 2 weeks this time but far from being over. Getting under I noticed at the end of the low pressure valve a drip, kind of yellow/orange oil. Looks like it ran down the low pressure tube out of the front evaporator.
I think I must have told this guy 40 times "did you check the evaporator?" He always comes back saying no leaks. So where the hell is this oil coming from? And I had some oil residue on my dash right in front of my far right hand air output. Hello!!! What is this?

This air thing is killing me. At the rate I am going I am lucky to get air by the time fall comes. It is hotter than hell here in Florida!!!

Great News on the RedTek. Even when it was running for a week the output was poor. If at night or early morning it kind of worked full up. During the day it did nothing. So once I stop all these leaks I will do the RedTek.

Great input

MT

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Originally Posted by PNW vanwagon

just topped off with redtek. after 1.5 - 2 years AC had gone from cold to slightly cool air. added one can and it's blowing cold again.

one question: while charging i was getting about 38 - 40 psi on the low pressure side and i think tim said the correct range was 21 - 28psi?

i might have a faulty gauge ? but it's working well for now but if anyone has feedback please let me know

here's a photo while charging: the gauge has several color coded ranges for R134A, R12 etc

*also has a highlighted optimal area or 65 - 80psi?

Attachment 7203

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The specs quoted in my earlier post were from the Toyota Factory Service Manual and is for R-12 Freon. Anything other than R-12 will likely have different pressure specs. You will need to refer to the specs of the specific product you are using (if other than R-12). I personally have only used R-12 in the van, so I am unable to comment as to what pressures you should see. It's good that it blows cold, so congrats on that. I'd be more worried about stress on the system (over time) if pressures are excessive. Tim

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Originally Posted by timsrv

The specs quoted in my earlier post were from the Toyota Factory Service Manual and is for R-12 Freon. Anything other than R-12 will likely have different pressure specs. You will need to refer to the specs of the specific product you are using (if other than R-12). I personally have only used R-12 in the van, so I am unable to comment as to what pressures you should see. It's good that it blows cold, so congrats on that. I'd be more worried about stress on the system (over time) if pressures are excessive. Tim

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yep i've been researching this some more - it's tricky using redtek and similar products as it's kind of in between the properties of r12 and r134a. i did find a chart for r134a calling for low side pressure to be 35 - 40 psi) but i'm not sure if redtek should be following the exact same numbers. the toyota manual says 28 max so i'll prob try and get the low side pressure down close to 28 and see how things go from there.

Attachment 7204

PNW - This is what RT has to say on the matter

AEROSOL CHARGING PROCEDURE
Follow all RED TEK® 12a safety precautions before initiating charging process.
1)	Before installing can taper (stock# 508) or Installation Kit (stock# 502) make sure valve is fully turned counter clockwise. Thread the can tap assembly on to the RED TEK® 12a can (stock# 301).
2)	Locate Low Side Service Port and connect hydraulic coupler by pushing onto male service port making sure hydraulic coupler is fully secured.
3)	Start the engine and place the A/C on maximum setting.
4)	Turn can tap valve clockwise into the can piercing the can seal.
5)	Invert the can. (Turn upside down). Make sure can is inverted through entire charging process.
6)	Slowly turn can tap valve counter clockwise allowing refrigerant to flow slowly into system.
7)	Continue with charging process as determined by the RED TEK® 12a conversion chart and adequate cooling is attained. Low pressure gauge should read between 30 and 38 psi. DO NOT OVERCHARGE! EXCEEDING 60 PSI ON LOW SIDE CAN DAMAGE COMPRESSOR!
8)	After RED TEK® 12a charging procedure is completed, turn can tap valve clockwise until valve is fully closed.
9)	Remove hydraulic couplers and charging hoses from low and high side service ports. Do not remove can tap if there is remaining RED TEK®12a inside can. Store unused RED TEK® 12a refrigerant in a well ventilated place away from open flames.
10)	Apply RED TEK® refrigerant identification tags in a highly visible area near charging port. -------------------------------------------------------------------------------------------

MT - Sorry to hear about all the grief, that truly sucks large, hopefully you get it sorted soon.

^ thanks burntboot ! i did see that info on redteks website. wonder if that upper end of 30 - 38 psi range is too much pressure on our vans compressor. also saw some VW vans use redtek and they found 30 psi to be the sweet spot. i'll experiment and see what works best. if it blows plenty cold at 30 psi - i'll go with that

Hey BB!
Ok, I finally was able to replace the evaporator and refilled (for the 7th time) with 134a. Compressor came up and cold air was flowing again. Not the greatest but at least when it down into the 80's down here is works pretty good.
It has now been almost a month since the change and it is still holding. I think I am going to buy a set of Red Tek and wait till spring to install. If the system holds the 134 through the winter I will be more comfortable it will hold the Red Tek for some time.

Keep you updated but even a little cool is good:lol:
MT

Well my brand new, OEM, Denso compressor failed on me after only 4 months of use. Yes I was using R134a, and I guess it's my own fault. They have a 1 year warranty but you have to have proof a shop installed it. This was an expensive mistake:wall:

That sucks. Do you think the system could have been overcharged? FWIW, overcharging is hard on compressors and is a leading cause of failure. Tim

I will admit I have made "shop" invoices for work I did myself to claim warranties. It has always worked, never once was I questioned. I would make a detailed invoice using a template I found online. To be clear, I never used actual shops information. I used all my own info, and made up shop name.

I figure I was a tech in a shop for several years, and ran my own auto repair business as a side job too. I feel I'm more than qualified to install parts. If they want to play games to save a buck, so can I.

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Originally Posted by timsrv

That sucks. Do you think the system could have been overcharged? FWIW, overcharging is hard on compressors and is a leading cause of failure. Tim

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I used about 80% of the factory requirement recommended for a dual climate/refrigerator system. I believe I did everything correctly, but I have been using the crap out of the AC (daily driven and AC always on) so I guess I got my money's worth, but disappointed it didn't last more than a few months.

Still working my AC issues. When the system is fully charged and working the cooling is horrible. Checked everything from 134 levels to air routing but no help.
I finally went to another shop and I was told something I literally did not believe.
So if any of you heard this one please chime in.
He told me that the reasons why the 134 was not as cold as R12 was due to the condenser fan. Yep, he claimed that the fan was not cooling the condenser enough to make the AC real cold. He said it was all that was needed for R12. He believes a bigger fan would improve this greatly. Is there any truth to this??
If it is true, has anyone tried doing this?
I am getting close to heat down here in Florida and would love not to roast this year.

MT

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Originally Posted by MyToy

Still working my AC issues. When the system is fully charged and working the cooling is horrible. Checked everything from 134 levels to air routing but no help.
I finally went to another shop and I was told something I literally did not believe.
So if any of you heard this one please chime in.
He told me that the reasons why the 134 was not as cold as R12 was due to the condenser fan. Yep, he claimed that the fan was not cooling the condenser enough to make the AC real cold. He said it was all that was needed for R12. He believes a bigger fan would improve this greatly. Is there any truth to this??
If it is true, has anyone tried doing this?
I am getting close to heat down here in Florida and would love not to roast this year.

MT

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He might be right to an extent, but R134 systems use a parallel flow condenser compared to an older serpentine style condenser like what is in the vans. The parallel flow condensers are a lot more efficient. I guess because the R134a isnt as efficient as the R12, it needs more cooling, but I'm not entirely sure a larger/better cfm fan would solve that issue.

I'm working on cooling/ drying my compressed air with an automotive AC condenser right now, and from all I've been reading, it is the condenser itself that is the biggest culprit. The 134 is not nearly as efficient as the R12 was, so when the switch was made, the manufacturers went to stacked plates condensers instead of serpentine tubing condensers (lots more area). I do not know which kind we have on the van but it might be worth investigating. Then again, it doesn't matter how big is the cooling area is if you can't bring cool air to it so a good sized fan might be all that's needed!

OOOPS ncbrock beats me to it :)

I agree with the above responses. The van's AC system was designed for R-12, so anything else you use will likely give you less than desired results. I'm still running R-12 and don't plan on ever changing over to anything else. That being said, even with R-12 the AC on these vans isn't the greatest. It's adequate for long drives, but not so great bringing a hot van down to a comfortable temp on the shorter drives. I would think anything less efficient than R-12 would make the system inadequate. Tim

Wow!!! You mean this guy could be right????

OMG, I thought total BS.

OK, so if that is the case what would happen if RedTech was used instead of 134?

Would both that and a bigger fan maybe get it cold?

Sorry guys, I am still nodding my head in disbelief.:no: Thank you so much!
I will start researching fans.

You say you are experimenting with an automatic condenser, what is that about. Is this something I can also capitalize on ?

MT

I'm far from an expert here because changing Freon types brings us back to the original engineering specifications (so it's an engineering question). The type of Freon used in a system is at the foundation of design and changing that creates huge variables. I personally don't think a bigger fan will completely solve the issue, but it would likely have a positive effect. Of course running a bigger fan would require more power and that could have other negative effects on the already weak charging system. To a small degree, this would also result in more heat generated in the engine compartment, and getting rid of engine heat is already an issue with these vans. Changing the condenser to something designed for 134A would likely have a bigger effect, but if you solve that problem, who's to say the evaporator(s) and/or the compressor wouldn't now become limiting factors. If going back to R-12 isn't an option then perhaps heat exchangers designed for 134A could be a solution. Unfortunately, unless you have the time, ability, tools, and materials to do this yourself I don't see it being a cost effective solution.

i can't find the link right now but if you get really desperate for cold AC i've seen a VW van with no working AC rigged up with an inverter generator on a rear rack powering a small regular portable AC inside the van that vents the hot air out a side window. the van's owners lived in the SW desert and needed AC big time in the summer and said it cooled off the van interior really well. AC ran off a remote control. obviously this is not optimal an optimal setup

Quote:

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Originally Posted by MyToy

Wow!!! You mean this guy could be right????

OMG, I thought total BS.

OK, so if that is the case what would happen if RedTech was used instead of 134?

Would both that and a bigger fan maybe get it cold?

Sorry guys, I am still nodding my head in disbelief.:no: Thank you so much!
I will start researching fans.

You say you are experimenting with an automatic condenser, what is that about. Is this something I can also capitalize on ?

MT

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I've heard amazing things about the red tek refrigerant. I believe it runs super efficiently and if I remember correctly you only charge it about 30% of the r12 value. I have cans of this ready to be swapped in in place of the r134, but the r134 worked well enough for me so I never swapped it out.

Tim is right, the AC system already isn't the best with R12, and with r134a it really isn't optimal. I'm not sure about my vent temps, but on a 90+ degree sunny day, the system can barely keep up, it's going to be a little uncomfortable (although still better than windows down). On an 85 degree cloudy day, it works decently enough to be comfortable. The sun is a killer.

Speaking of add-ons, Thermo King, Carrier, and possibly other manufacturers make add-on AC systems for vans and refrigeration purposes (catering and food transport vehicles). I was considering such a system for my van but these are commercial systems that come at commercial prices ($3,000 + for just the parts). The only one I'd seriously consider would be direct drive, meaning an engine mounted compressor with pipes carrying the Freon to and from the rooftop unit. If you could not do it yourself it would be a very expensive installation.

There are also RV type electric rooftop units, but these would only work when parked and plugged into power. A generator could be used to run during driving, but mounting, venting, rigging, sound proofing, etc would expensive and problematic (not to mention the space issue). There's also the possibility of powering off a large alternator with an inverter, but that's not without a large price tag and it's own set of problems.

Considering what a PITA add on vehicle AC systems can be, the type of system shown below starts looking much more appealing. Tim

http://i8.photobucket.com/albums/a23...pscyaprlbl.jpg

I'm not an expert and definitely do not have Tim experience with this, but it seem to me we are not trying to push more gas through the system, just to cool that same amount of gas better, so the compressor and evap. should be fine. No?

MyToy, Your Van is a 2wd therefore the ac condenser is cooled by the mechanical engine fan pulling air through it. How does your guy propose to make the fan bigger?

Quote:

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Originally Posted by Carbonized

I'm not an expert and definitely do not have Tim experience with this, but it seem to me we are not trying to push more gas through the system, just to cool that same amount of gas better, so the compressor and evap. should be fine. No?

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Yes, I agree that a good efficient condenser with cool air moving past it is definitely the most important issue here. However, a properly engineered system is usually preferred over one that's been hacked and modified. Once you start making changes other unexpected things can happen (that was the point I was trying to make). If you find a way to retrofit a modern condenser/fan unit here (designed for R134A) I think you will see a marked improvement. Tim

MT - I would have called BS on that explanation too, glad to know there are far more intelligent peeps around.

If the system's bits are now functioning as designed and there are no further leaks and you aren't bothered about warranties, then I would probably give the Redtek a chance.

Its easy and cheap and if it doesn't work, you can still re-engineer the system :)

I totally get your point, but the hacking started with the switching gas and we are eternally going to be chasing the next weakest link :LOL2: