X2. I share that concern as well. Sounds like you've got a plan to brace it back up though, so obviously you've given it thought.
Crew cab rear AC
- Thread starter RLDSL
- Start date
X2. I share that concern as well. Sounds like you've got a plan to brace it back up though, so obviously you've given it thought.
david85
Full Access Member
Whew, thats a big relief then. Sounds like you have everything planned out then.
Well, I had to take the thing out this evening for an emergency run to retrieve one of our cars that had broken down ,WOOOEEE that sucker is cold inside. My left knee was getting numb. 32-33 deg out the ducts just at crawl around town speed and the young'uns were all smiles in the back seat. Good thing they brought blankets. They are seriously happy with this little mod
No more sweaty kids that's for sure.
No more sweaty kids that's for sure.
93 f350cc 7.3 na
Registered User
This thread is what I have been looking for. I had the same idea and removed a very similar rear ac unit out of our 94 e150 conversion van we got rid of along with every other piece of the conversion and some factor ford parts. Was wanting to fit it in my 93 crew cab when I redo the interior. I would be very interested in knowing EXACTLY how you got yours to work and blow such cold air. I figured rigging up the heater part would be easy but had no idea how to go about the ac side of things.
One of the reasons i haven't started working on this project yet is my factory ac is not working right(I have replaced every part on it, compressor, condenser, evap, hoses, everything)and it still blows off at the manifold after sitting in park for 3 min. Going down the road is ok but the thing just isn't getting that cold.
Would like to hear more. Thanks
One of the reasons i haven't started working on this project yet is my factory ac is not working right(I have replaced every part on it, compressor, condenser, evap, hoses, everything)and it still blows off at the manifold after sitting in park for 3 min. Going down the road is ok but the thing just isn't getting that cold.
Would like to hear more. Thanks
You have a head pressure problem. main reasons for having refrigerant blowoff is a failed fan clutch, but it has to be completely shot for that ( total loss of airflow across the condenser at idle ) You could try rigging an electric pusher fan on the condenser and see if that stops it, if it does, then you have found the culpret.
other possibility ,I'm guessing the old compressor failed by locking up or making crunchy noises. I bet when you replaced it you didn't get the system flushed out thoroughly and the orifice tube is clogged causing an overload on the head pressure making the refrigerant all escape through the blowoff valve.. All it takes is for some crud to be hiding in the evaporator and it will circulate through the new system. Open it uop at the orifice tube and if it's got gray yuk on the screen, you need to take it all apart again and flush the snot out if it and install some filters in the lines to prevent it from happening again. Now if by chance the screen is clean, then you just have a bum blowoff valve. Not sure if that is available by itself, but if it's bad, I have a used hose assembly that has fairly new rubber on the low side that you are welcome to have that has a good blowoff valve on it.
Feel free to PM me and I'll be happy to walk you through any of this.
Fozz
Full Access Member
I was thinking of a/c in the back too, but I was thinking of just redirecting some of the factory air under the front seat to the back with some ducting. I think that would be a lot less work.
93 f350cc 7.3 na
Registered User
RLDSL Thanks for the reply back. When i replaced the ac system there was allot of trash by the orfice tube and grey goo as well so i replaced the compressor, condenser, liquid line, orifice tube, evaporator, dryer, and return line which has the pop off valve on it. So the entire system is new. Had the system pulled down for about two hours then filled it up with r134a.(was converting over the system at time of install) The compressor clutch seems to almost always be engaged and it doesn't act as if it cycles off and on much. I noticed there being a screw inside the pressure sensor that threads into the side of the dryer that controls the comp clutch(i think?); does that have anything to do with it not cycling the compressor? Also the truck is serpentine belt if that makes any difference in the setup.
I think this might need a new thread?
Thanks Aaron
I think this might need a new thread?
Thanks Aaron
If it's all new but you are blowing off pressure at idle, then it is a bum fan clutch for sure. If you don't get enough air flow across the condenser it will cause an unsafe rise in pressure and cause the system to blow off like that. Depending on how good the vacuum pump is that was used, 2 hours may not have been enough time to boil off any moisture in the system. A REAL stout vacuum pump( like I have) can do it, but not very many people spring the bucks for one that stout. Most on a system that's been wide open need to suck down overnight.
Also did you remember to add the correct amount of oil to the system?
93 f350cc 7.3 na
Registered User
Yes i did add the amount of oil it called for and i had a family friend pull it down at his shop with his snap-on vacuum pump. (Wish i had the money to buy snap-on lol) Thanks for the advice on the fan clutch. I think it is time for the electric fan upgrade.
If you want to go that route, you can get a duct setup with a blower in it to boost the airflow I can find a link if you need it.. They make that setup just for getting air to circulate to the rear of a vehicle. It would help some. Personally, I just wanted the seriously extra cold all around because i can't stand heat.
It was bad hot yesterday and we went out to hit a bunch of yard sales and we stayed chilly comfortable. With that extra setup on there , even when i shut it off, it would be hot as heck when we got back it, but only took a couple of minutes to be chilly again. Didnt even have the blowers running full tilt. Just the factory setup with an extrablower wouldn't do that.
Really nice thread! So basically, you turned your crew cab to have an A/C system like in a van. Is it plumbed exactly....(granted, I haven't seen a schematic of my van's A/C plumbing).
I don't want to sound over bearing, but I'd love to ask you a few A/C questions. My old 91 Sable has been giving me fits and I can't figure out what it is. Sometimes it works, sometimes it doesn't.... fades.
I don't want to sound over bearing, but I'd love to ask you a few A/C questions. My old 91 Sable has been giving me fits and I can't figure out what it is. Sometimes it works, sometimes it doesn't.... fades.
Snap on makes pumps in a few different grades. what matters is the motor size and how deep a vacuum the thing puts on a system and the flow rate.Most snap on pumps would still require you to suck down overnight for a system that has been wide open. They only flow 1.5cfm( one is even made in china
shame on snappy 
. Snappy only has one real commercial grade vac pump and it tops at 5 cfm and they get about $440 for the thing so they don't sell too many. If he had the 5 and it was pulling the system down to30 in, then 2 hours should do it , but a 1.5 cfm pump isn't going to do it in that time frame. There are very few pumps that will pull a hard enough vacuum to be able to dry out a system in 2 hours or lessI have one. a couple of years ago when I bought it , it was the stoutest one made at 6cfm, but now robinair makes an 8 and 10 cfm model. Really overkill for car systems, more for commercial refrigeration techs.
Anyway, if you don't boil all of the moisture out of the system, it is possible to suffer internal evaporator icing, especially on one like is in these trucks where both openings are high on the thing. IT's rare, but if extreme, it can cause a blockage
Yes, it's plumbed in exactly like a van setup
PM me about your sable, we'll get it figured out
BigRigTech
Diesel junky
I've had people tell me to vacuum for hours and hours and I've had guys tell me 25 minutes is plenty as long has you have replaced the dryer....Personally, I vaccumed my truck for 20 minutes, charged it with 2lbs 12oz of 134A and it's ice cold. It was 34C (93F) here yesterday - which is about as hot as it gets here in the summer and Dad was more than comfy driving the beast while I sweated like a cat in a chinese restaurant driving my $500 dump truck home.
I've had people tell me to vacuum for hours and hours and I've had guys tell me 25 minutes is plenty as long has you have replaced the dryer....Personally, I vaccumed my truck for 20 minutes, charged it with 2lbs 12oz of 134A and it's ice cold. It was 34C (93F) here yesterday - which is about as hot as it gets here in the summer and Dad was more than comfy driving the beast while I sweated like a cat in a chinese restaurant driving my $500 dump truck home.
I hear rumors like that all the time, problem is most people don't understand the reason and principles involved in vacuuming out a system. They think that just getting the air out does the trick. You can get a system to function basically that way , and in your climate, an AC system could be a marginal performer and do just fine, In severe heat climates, you can't get away with that stuff. Even with a real stout pump, on a system that has been open to the elements for an extended time I have seen vapours coming out the exhaust of the pump after over an hour at over 30 inches and let it run a lot longer to every last bit. An average pump that runs at a much lower flow rate and would likely only be pulling 27-28 inches would take all day to get that out ( main reason I spent a fortune to get the stoutest pump made at the time because I do a lot of AC work and the wimpy pump I had was costing me a fortune in electricity to fully evacuate systems)
Think about it, how long does it take to boil water on a stove, you fire up the stove full tilt, and have to wait till it gets to 210 deg f before it starts to boil, then for it to evaporate takes a while from there. Now consider the inside of your ac system. Placing the system under a vacuum decreases the temperature at which the water will boil, in essence you are getting water to boil at room temperature. No easy trick. First the system has to be drawn down till atmospheric conditions in the system are conducive to boiling at room temp, then it takes the time for the boiling to actually begin, once it boils it expands and can be drawn out and that is dependent on the flow of the pump. This all takes a lot of time.
Trying to depend on the dessicant in the drier or accumulator is a non starter because that is only there to handle the very small amount of residual moisture that can remain trapped in a system even after a thorough evacuation, it is never intended to handle the amount of moisture in a system that has not been properly evacuated.
