1968-Present E-Series Van/Cutaway/Chassis Econolines. E150, E250, E350, E450 and E550

A/C question

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  #16  
Old 09-23-2017 | 12:23 AM
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annaleigh
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Good then we know your system matches the 85.
Something I often do when working under the dash is use mirrors and a flashlight. i have a 12"x8" I can prop up on the floorboard and a smaller 2"x3" I use in tighter spaces.

The vacuum motor I circled in green operates the ac/heat door. With vacuum applied it closes off the floor and defrost vents forcing the air flow to the dash vents.
1- The easy way to check that is to put the fan on high and the selector lever on vent. All the air should blow out the dash registers. If any air blows out the defrost or floor vents during this time, there is a problem.
2- Next move the selector lever to floor with the fan on high. The only place you should feel air is out the floor vents.

Step 3 will check door #6 and #7
3- move the selector lever to mix with the fan on high. You should get No air out the dash vents. You should have air out the defrost and floor vents.

Step 4 checks door #6 and #7 also.
4- move the selector lever to defrost. You should get no air out the dash or floor vents.
If there is a problem with any of these steps then you need to check the vacuum motors, vent doors, linkage to them, or vacuum hoses.

I was glancing at the manual on removing the dash and you really don't want to do that. I need to pull just my instrument cluster out and have been avoiding it for a year now! If you do wind up pulling the dash out there are a few things you might want to change while you have it open like all the instrument and dash light bulbs, lube the speed odometer cable, and you have 2 flashers, one is behind the instrument cluster. A good vacuuming probably wouldn't hurt either.

I replaced my ac system also last summer bu ti went with R12. I read that the condensers are designed different for R134. R12 uses a round tub and fin design while R134 uses a flat tube or parallel like design.
I have also read where some guys say the R134 works just as well but that you have to be a little low on the refrigerant charge. I do not know if that is true or not. It might be worth you researching a little.

One thing i do know affects the temperature is the besides the fresh air vent is the clutch cycle switch. Some people call it a low pressure switch, Ford calls it a de-icing switch. They sell 2 different ones. One for R12 and the other for R134. With R12, our system calls for the compressor clutch to cut out when the low side pressure reaches 28psi and cut back in at 42psi. The switch is adjustable. If you remove the electrical connector you will see a screw down inside the switch between the two connector prongs. You really need to have a set of gauges connected to adjust it. Don't quote me on this because it is coming from another site, but the cut out pressure for R134 should be around 21psi. IF the pressure is set too low, the evaporator will ice up and the air will not be able to flow through it. Hence Ford calls it a de-icing switch.
I adjusted mine down to 25 and the ac temperature went down 5 degrees and it never iced up.

Another thing that can cause problems is the amount of oil you add to the system. More oil then the system calls for takes away space for the refrigerant to be compressed and expand. Too little and you damage the compressor.

On the 85 if the heater valve is not shutting off all the way or the cable controlled temperature blend door is not closing all the way, both allow heat into the system. On the 88 there is no heater valve so the heater core is hot all the time.

When yo replaced the evaporator, the evaporator lines that come out of the back of the box into the engine compartment, those need to be sealed with some putty or something so no air is sucked inside the box.

As to your temperature of 55f that is about what mine averages on a hot sunny day. Several other people on this forum have said that 55 is pretty average. I have a high top conversion van and placed a thermometer in the vent, middle of the van, and at the back bench seat. After driving 30 miles on the freeway the vent temp was 55f. The middle of that van was 85f and the rear seat was almost 100f. Our vans are a big box for a single front ac to cool down.
On a cloudy day after driving a couple of house, the van will get cold enough to where i have had to turn the fan down. Think about it, a F150 uses almost the same parts and only has to cool down the front cab, a much smaller space. Those are the guys that get 35f out the vents. They are not recirculating 100f degree air...
 
  #17  
Old 09-23-2017 | 10:27 PM
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raye321
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A/C question

Is R-12 still available? I would replace the system with R-12 if I could get it.
Yeah I agree, there is lot of very hot air in the van on an 85 degree sunny day. I have a divider behind the seat but still, alot of hot air gets into the cab. If I'm driving down the highway and it's 85 degrees and sunny , it is hard to cool the van down but if the sun goes behind some clouds it cools down to a comfortable temp pretty fast.
 
  #18  
Old 09-24-2017 | 01:39 AM
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annaleigh
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Yes R12 is still available. I bought mine on Ebay. Be careful though and watch the sellers rating. I have heard that there is a lot of fake R12 being sold as the real stuff. The R12 I bought was in older looking cans that way I was pretty sure it was real R12. I bought 8, 14 ounce cans. It takes 56 ounces to charge the system and that is exactly 4, 14 ounce cans. The other 4 are for are in case i need to recharge the system.
NOTE- If you don't have a set of small scales, find someone who does and weigh the cans before and after because some cans can have more or less then others.
Here is an example of a can I would think about buying and the guy has 100% positive feed back.
National R12 Refrigerant - Full 12 oz Can | eBay

Now I was told that to legally buy R12 you need a EPA 609 certification and that sellers are not legally supposed to sell it to you unless you are certified, so i got certified. I bought 8 cans from 2 different sellers and no one ask me for my certification number like they were supposed to.

If I can pass the test then I know anyone elese with good common sense should be able too... i studied the information at the site link below, took the practice test and then took the final real test and passed. I don't remember 2 or 3 hours total. The trick for me was to just set aside the time and do it all at once while it is fresh in your mind. If I had studied and taken the test a different day, I might not have passed.
https://www.epatest.com/

Another thing about the heat is that since the engine is part way in the cabin area, there is a lot of heat generated just from the tight space in vans that you don't have in a car or truck.

If I had to do it all over again I might have just gone with R134 because eventually I may have to since I plan on keeping the van. I went with R12 because that is what the system was designed for and the operating pressures are lower with R12 then R134. I replaced the compressor with a new Motorcraft compressor and thought the higher pressures with R134 would have to affect the life of the compressor.
 
  #19  
Old 09-24-2017 | 09:40 AM
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A/C question

Thanks Annaleigh great info. I went on ebay and your right, have to watch. I think some ads on there is acually r 134 and advertised as r-12 replacement but it is r 134 to replace r 12 systems.
I was told that r-12 is superior to r 134 in cooling power. It is expensive. I dont mind spending the money to get the original cooling for the older system but if I lose it that's when it gets expensive. It is odd though, I have a 1989 Mercedes that was r-12 converted to r134 and it doesnt matter how hot it is, I can put the fan on low and it still gets darn cold in the car. I agree with you that the van is different. I think perhaps my a/c is working as good as it can but with the large cargo area filled with very hot air and the engine partially in the cab area when it's in the 80's and the sun is coming through the windshield it is hard to get it to cool down with the r 134.
 
  #20  
Old 09-24-2017 | 11:10 AM
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A/C question

What is the test certification # you took? You mentioned a practice test, where can I find that? I have been reading about a product called FR-12 by pennzoil. It is for older r-12 systems and supposed to be better than r134, less pressure on the compressor and gets colder than r134. The price is reasonable as well. But you still need a certification to but it.
 
  #21  
Old 09-24-2017 | 01:51 PM
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annaleigh
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Well I don't see the practice exam on that site any longer.
It is an open book exam and the download is on the exam page
https://www.epatest.com/609/openbook/

You will have to do a search for "EPA 609 Practice Test"
unless you find a really good practice exam from one site, I would do multiple practice exams from different sites. Because it is open book, download the book and leave the window open with the book while you do the practice tests and the actual test!

I remember reading a little about the FR12 before deciding to go with standard R12 but I don't remember what the exact issue was for me. It may have just been I wanted to put it all back like it came from the factory.

If you do go with any other refrigerant, make sure you flush your system and use the correct refrigerant oil. Ford used a special paraffin based mineral oil. I can look up what I actually used and let you know. I remember I couldn't find it online. I had called a ford dealer and gave them the part number. They didn't have any but found a dealer who did and I ordered it from them.

Did you replace or change the pressure setting on the de-icing switch when you converted to R134a?
 
  #22  
Old 09-24-2017 | 02:31 PM
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A/C question

No, I didn't do anything to the pressure setting
I was reading were the FR 12 is a blend of 134 and 146 or something like that and butane so I'm not sure how good that would be but it says it is as good as r 12.
 
  #23  
Old 09-24-2017 | 05:25 PM
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I think the butane was part of the reason I didn't use it. Everyone has their own opinions about having butane in the ac system but i read some posts about what wold happen if you were in a freak accident where you had a fire and the evaporator started leaking. It may not be allot of gas but it could produce a small fireball.. BUT there are probably lots of cars out there running it.

As to the pressure switch... Everything i have read says that you have to lower the cut out pressure when you convert to R134 so that may be part of your problem..
When the compressor is running the suction pressure drops. The lower the suction pressure is the colder the evaporator temperature will be. With R12 Ford says to set the cut out pressure to 28psi. Everything i have read about R134a is to set the cut out pressure to 19 to 21psi.
Each different freon has a different temperature at the same pressure. At 28 psi on the suction side, with R12, the evaporator temperature is around 29 to 30F.

With R134 set to the cut out pressure of 28psi, the evaporator temperature should be around 33 to 34F.

Maybe because the two gasses have different properties when it comes to absorbing heat, the temperature of the R134 needs to be lower. By setting the switch to say 20psi, the evaporator temperature lowers to around 20F

So if your cut out switch is still set to 28psi, your evaporator temperature is averaging 33 to 34F when it should be around 20F. That is 14f degrees colder then you are running now, if your switch is still set to 28psi.

You really need a set of gauges to check the high and low side pressures as that can tell you a lot about how your system is working. As the suction pressure is lowered, the high side pressure rises and you should make sure you are within save ranges.

I have my switch set to a cut out pressure of 25psi. That means that the evaporator temperature is around 26f for R12. How do I know that? If you look at the pic below the blue gauge has the suction pressure/temperature. Towards the inside of the blue gauge you see 3 different red scales. The center one is for R12. The inner black scale numbers is the suction pressure. So at 25psi, you follow the needle down to the middle red R12 scale and you see the temperature is about 26f



here is a gauge that is for R134 and i put a red line across the scale to show the pressure / temperature. The inner light blue scale is the evaporator temperature while the very outer scale is the pressure.


Now you can just do a trial and error on adjusting the switch. If you get the temperature too low the evaporator will ice up. Also too low and your compressor will not cycle off and on like it should. here is some posts about that.
http://www.autoacforum.com/messagevi...threadid=15799
 
  #24  
Old 09-24-2017 | 05:50 PM
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annaleigh
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this is called HC12a so I dont know if it is the same as FR12
 
  #25  
Old 09-27-2017 | 06:19 PM
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A/C question

I think I will stick with R 134. Not only for the fire hazard but I was thinking about the a/c system itself. It may mess up the seals and also the seals etc in the compressor.
I was traveling in my van the past few days and one day it was really hot upper 80's and humid in Maryland. I had a few cans of 134 with me and a dispenser with an inline gauge. I got frustrated with the heat and decided to add another can. I had replaced the low side adapter before I left because the old one was no good. Pull a vacuum and filled the system to 56 oz, which is what the sticker says on the inside hood. I connected the hose and checked the gauge. It was the same as when I filled it earlier, just barely touching the bottom of the blue f band which indicates fill zone. It sucked the can up quickly and raise the needle about 1/4 into the blue zone. now that made 56 oz plus another 12oz. It did help alot in the hot weather. I could probably put at least another can in and still not be near the upper blue zone but I don't know if that would be good to do as it would put it way over the fill recommendation.
Also another interesting thing happened. I was stuck in traffic for about 20 min inching along until I could finally accelerate onto the highway. When I pushed the gas pedal down the van started to die like it was out of gas, I pumped the gas a few times and still was dying then perked up and was ok until I stopped for gas. It took only a few min. and when I accelerated it did the same thing only a shorter amount of time then was ok. Any ideas what it could be. Never had that happen before. It was very hot out, I dont know if that had anything to do with it or not. The fuel pump only has about 20,000 miles on it. I thought maybe it was going bad but it was fine the rest of the 3 hours trip home.
 
  #26  
Old 09-28-2017 | 12:29 AM
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annaleigh
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Do not add any more refrigerant to the system without real gauges connected to it!
Overcharging a system can damage the compressor and blow seals as it will raise the pressures to unsafe levels. Those little gauges on the hoses are not known to be very accurate..
You really need to get some gauges and see what the high and low pressures are.
I think you would do better trying to lower the cut out pressure a couple of degrees.

As to the stalling,, possibly,, when sitting traffic the there is little air flow around the engine and so the engine compartment gets really really hot in traffic. I don't recall if you said what engine you have but the 86 with a 5.0/302 has a TfI ignition module on the side of the distributor. They were known for going bad due to high temperatures at the distributor. Ford finally relocated the module to the fender well to solve the problem. Does your van have a carburetor or is it fuel injected?

If it is a heat related problem that has never occurred before, perhaps it cold be related to the AC system. The older Ac compressors take anywhere from 5 to 10 hp from the engine. IF the system is over charged it requires more hp to turn the compressor and so could cause the engine compartment to get much hotter then normal.

I would post this question in the forum as some of the guys there have more experience with this kind of issue then I do.
I have done valve jobs, head gaskets, timing chains, and have swapped out a couple of engines but so far have never owned or worked on a car that wants to die when hot... Knock on wood!
 
  #27  
Old 09-29-2017 | 07:43 AM
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A/C question

I do have as set of gauges for A/C. I know the gauges on the dispenser are not very accurate. I will put the gauges on and see what the low side is showing. It shouldn't be any higher than 45, right?
I have a 300ci 6 cylinder (4.9L) with a 1 barrel carburetor. Amazing, you would think they would put at least a 2 barrel carb on it! But it runs well. I had the engine rebuilt a few years ago. A beefed up cam shaft was installed to take heavier loads easier. Manual 4 speed trans on the floor.
I was thinking that the cutting out problem could be the ignition modulator or maybe a vapor lock in the gas line due to the hot weather. The modulator was replaced when the engine was rebuilt, maybe has 20,000 miles on it. I had every outside component replaced when the engine was rebuilt. But new parts go bad too.
 
  #28  
Old 02-02-2018 | 10:50 AM
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Check for a plastic bag stuck to the recirculation inlet

I know that this is an old thread, but it might be helpful to someone, so...

I just took my 99 F250 to the mechanic and he replaced my compressor and condensor. I had mentioned how it blows just fine on regular ac, but how when I put it into Max AC (recirculation), it stopped blowing (weak, almost nothing).

I got the truck back and the AC worked great. He said that he told his guys to check the Max AC issue, but they said that it worked fine. I hopped into the truck to check and the problem was still there. He said to bring it back and they would try to fix it - he named off most of the things that I have been reading on this thread.

On another thread, one poster mentioned to check for a plastic bag. The more that I thought about it, the more likely it sounded. If the door that switched from outside air to recirculation was not closing, then the availability of outside fresh air would still allow the fan to move air out of the vents at speed. It didn't seem like a blend door issue either. Last night I went out in the dark with a small flashlight and could not find the inlet for recirculation mode.

This morning, I went to check and sure enough, there was a Lowes bag that had ended up stuck to the inlet. I pulled that off of the inlet and now everything works great!

I think that I haven't had Max AC working for several years! Regular AC was working pretty good for me, so I never looked further (I know, what a dope!)

Also, regarding the dealer telling you not to use Max AC all of the time, you can do it if you make sure to turn it back to Regular AC before you turn off your truck - that will open the door to the exterior and let everything dry out.

It probably depends alot on where you live. I imagine that in places like Florida or states on the gulf coast, the humidity is so high that running Max AC might keep things dryer inside of the duct system. Still, moving the control back to Regular AC might help.
 
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