87 Ranger Retrofit Help

[boyluke2413]

Hello all. I drive a 1987 ford ranger XLT with about 120k miles, been daily driving it for almost a year now and its great and rarely gives me issues. Being its an XLT it has factory air conditioning, r12 of course, and ever since i got the truck the system was empty and it has been empty for 5+ years (truck sat not running for years before i got it). I recently started driving 90mins to work, and with this summer heat, i finally decided to retrofit my ac system.

So far, I have-
-replaced compressor
-replaced drier
-added retrofit fittings
-replaced all o-rings
-blew out condenser with compressed air
-tomorrow i will install the new orafice tube

I might also add, i took the old compressor off a few months ago so the system has been sitting open since then until yesterday.

So the only thing occupying the a/c system right now is the 5.4oz of pag oil that came in my new compressor.

I found a chart saying this truck is supposed to take 44oz of r12, and 10oz of mineral oil.

My understanding is that im only supposed to charge to 80% of the r12 capacity, which in my case would be about 35-36oz of r134a.

Do i still put 10 total oz of pag oil in it, or does that capacity need to be adjusted as well? And i can just dump that into the compressor and it will cycle to the other components, yes?

How exactly would i go about charging this system? Ive heard that when doing a retrofit, you should charge only by the low side. Does that mean i am to put 35oz of r134a into the low side only and i should be good? (after adding the 4.6oz of remaining oil of course)

Sorry for the lengthy post, I just want to make sure ive done everything properly so i can hopefully get the system working on Monday.

Any insight? Things ive missed? Recommendations before charging? Im all ears to any opinions or suggestions, i have never worked on an a/c system before so this is all fairly new to me.

 

[RonD]

Yes. put the oil in compressor

You add refrigerant to the low side, always, pressure in the high side can be way too high and exploded the can, but only a running system
When AC is OFF pressure equalizes so there is no high or low side, after an hour or two

Examples of low and high side pressures in working AC system : https://carcody.com/wp-content/uploads/2020/05/r134a-low-pressure-chart.jpg

Hotter it is outside the higher the pressure inside a running AC system
You will be filling a system with 0 psi so I guess you could use either port BEFORE activating the Compressor

If possible use refrigerant with DYE already added, in case there are leaks

 

[boyluke2413]

Thank you RonD

I will charge it on the low port either way, but is it better to charge it with it running or with it off for minimal risk?

I have a bottle of pag oil that came with my "compressor and component kit" from rockauto, im not sure if it is dyed i will have to check tomorrow when i go to add it.

 

[RonD]

You can also just add dye since its 0 psi now

 

[boyluke2413]

That works too. So ive got that orafice tube and some oil to add tomorrow and i should be set to charge it up on monday I'll be back then, to report how it goes. Hopefully theres no leaks. Thanks again for your help

 

[19Walt93]

I would flush the condenser, lines, and evaporator with a/c flush solvent first, then blow them out with air. I would also have it evacuated before charging it, that will remove the air from the system.

 

[boyluke2413]

Well I'm back. I replaced the orafice tube (the old one was nasty too), and attempted to evacuate it and charge it today. It thankfully holds pressure, it appears it has a very small leak but its small enough I can just let it ride and fix it later when I find where it is.

Here's the problem - There's blockage somewhere. I am going to thoroughly flush *everything* out with brake cleaner and compressed air and put another fresh orafice tube in there (maybe just clean this one and reuse it since its new). Once that is done, I'm going to try charging it again and if it has the same problem I'm going to replace the condenser and evaporator (the evaporator is the only thing I didn't spray out so I bet that's where the blockage is)

The condenser fins were all jacked up, which may have been contributing to my truck running hot in city traffic so I used a screwdriver to straighten it all out as best as possible.

Before-

After-

Definitely should have more airflow now.
Here's hoping I can get away with flushing it instead of buying more parts.

 

[Vindictus]

Did you change the condenser? They don't always flush good. when I did mine last year I bought the kit from rockauto. compressor, lines ,orafice tube, dryer and condenser. Works great.

Resurrecting Your Ford Ranger Air Conditioning

www.therangerstation.com

 

[boyluke2413]

I did not change the condenser, the kit I got from rockauto came with the compressor, dryer, orafice tube, and o-rings. The only things i didnt replace is the pressure switch, condenser, evaporator, and the lines.

 

[RonD]

How did you decide a blockage?

compressor to orifice tube is the high side(thru condenser)
orifice tube to compressor is the low side(thru evaporator)

So was the pressure too high on the high side or too low on the low side?

 

[boyluke2413]

the pressure was too low on the low side. 0psi in fact. by the way, I actually am doing this in a shop with professionals and a high end a/c machine. It definitely comes in handy sometimes to work at a shop.

 

[boyluke2413]

And im back again. After cleaning everything out with brake cleaner and compressed air, i charged up my ac today, and IT WORKS! Blows cool enough at idle, but it gets *ice* cold as soon as im moving down the road.

However, I now have another issue. Not sure if i should post this somewhere else since it no longer is dealing with a/c but here it is anyways.

When im sitting at idle or driving in city traffic with the a/c on, my temp gauge will be almost on H after 10 or 20 minutes of driving if its hot outside. It really does not like sitting still. Once im on the highway, the temp will bring itself down gradually and itll sit right above half all day long with a/c on. Even with no a/c, it would still run warm under idle and stop&go conditions but it never overheated on me. It did not overheat on me today but it got darn close, before i turned the a/c off and the heat on. Not trying to deal with cracked heads

Fan spins only about once after turning the engine off, and i cannot stop the fan with my hands while its running so i think its safe to assume the fan clutch is fine. If i look inside the radiator while it is running, i can see that there is *plenty* of coolant flow so i dont think its a thermostat or water pump or anything like that. Im going to flush the radiator and engine tomorrow anyways, this coolant isnt as green as it used to be but i dont expect it to make a difference. The only thing i can think of is maybe a better fan will help? Because of both the running hot and the ac not working as good at idle, maybe all it needs is more airflow? If not, maybe a radiator swap for a larger one?

Even though my fan clutch seems okay at 120k miles, ill probably slap a new one on there anyways, cant hurt to try for 30 bucks.

 

[RonD]

Its the fan clutch OR............water pump impeller blades have worn down

Before starting the engine in the morning or after it has been sitting for at least 5 hours
Open the hood and try to spin the fan, it should be tight, hard to spin, that's cold locked, if it spins easy then clutch is bad
Start engine, you should hear the fan if it was cold locked, then noise will go away after 5 seconds, shut engine off
Now fan should be easy to spin, unlocked

After getting home, at least a 15-20min drive, longer the better
Shut off engine, try to spin fan, should be locked hard to spin, if not clutch is bad
You should HEAR the fan when temp gauge gets above 1/2 on the gauge

No easy diagnostics for water pumps, but if its not the fan clutch then water pump is next


And since you retrofitted an AC condenser in front of the radiator, you also should have a dual core radiator
Manual trans with no AC would usually come with single core
With AC often got dual core, automatic always got dual core
If you get a dual core then you also need another fan shroud for the dual core, its shorter

 

[boyluke2413]

Thanks for your help RonD. Well, the fan pretty much freewheels when the engine is cold, and it has some resistance to it when its hot but its never locked in place. looks like its time for a fan clutch, i will replace that and report how it goes.

Edit- if i am correct, i should be able to swap a 4.0 radiator out of a early 90s explorer with an automatic trans and a/c? i did a little research and it looks like specifically *that* version of the 1st gen explorer has a nice beefy radiator that will bolt into my ranger.

 

[RobbieD]

Edit- if i am correct, i should be able to swap a 4.0 radiator out of a early 90s explorer with an automatic trans and a/c? i did a little research and it looks like specifically *that* version of the 1st gen explorer has a nice beefy radiator that will bolt into my ranger.

Yes. I've done the early Explorer auto w/ AC radiator into a '90 model with a 2.9 manual. I "think" that I needed to use a 4.0 upper hose, trimmed a little (it's been a while ago). I don't know if there's any further difficulties on an earlier truck, like your '87.