1989 2.9 Automatic, A/C delete?

[eightynine4x4]

Been searching to find an answer to this but alas am resorting to the forum!

Doing other work and looking to gain some engine bay clearance for a while.
I’ve never had the belt on the A/C so it’s just sitting. Don’t care for the convenience of AC either so won’t be restoring it for a couple years at least.
Not sure how the tubing works and what it does. One tube is connected to radiator and other to vertical canister near passenger firewall. Said canister then connects to a plastic unit that contains the heater core.

Can anybody give an opinion on if the two hoses that hit A/C can simply be stopped/capped and that’s it? Or is there flow of coolant or refrigerant ongoing that can’t stop up?

 

[RobbieD]

Not sure how the tubing works and what it does.

Before you do anything make sure that the AC system has ZERO charge. Find the service ports and depress the Schrader valve service ports (same as a tire valve) and make sure that there's no pressure in the system. You can easily get injured opening a charged system.

Looks like there's service ports on the compressor fittings, and I can't tell if that's a service port on the accumulator/drier or if it's an overpressure safety valve. The compressor has been replaced before, but the rest that I can see looks stock.

Once you've confirmed that the system is empty, you can remove any of the components that you'd like. A non-AC heater box would give you more room and the best appearance if wanting to completely remove the AC.

 

[eightynine4x4]

Before you do anything make sure that the AC system has ZERO charge. Find the service ports and depress the Schrader valve service ports (same as a tire valve) and make sure that there's no pressure in the system. You can easily get injured opening a charged system.

Looks like there's service ports on the compressor fittings, and I can't tell if that's a service port on the accumulator/drier or if it's an overpressure safety valve. The compressor has been replaced before, but the rest that I can see looks stock.

Once you've confirmed that the system is empty, you can remove any of the components that you'd like. A non-AC heater box would give you more room and the best appearance if wanting to completely remove the AC.

Got it thanks!
Understood about the steps.
Out of curiosity, is the cold air sent into the same box as heater core and then distributed the same way as heat is?
And if so, why is the heater core in the same box as where the accumulator/dryer (vertical canister) is connected? If the heater core is constantly at engine op temp, that seems like a lot of heat to overcome and then make air cold.
Just trying to understand the system before I start planning to delete.
Is the hose coming from radiator an isolated / separate refrigerant? Or is that full of basic coolant and connected to rest of coolant system? And what’s inside the hose between compressor pulley unit and canister?

 

[RobbieD]

Out of curiosity, is the cold air sent into the same box as heater core and then distributed the same way as heat is?

The box (or plenum) has a blend door to regulate between hot and cold functions. The AC's evaporator ( / cold, versus the heater core's / hot) doesn't do any cooling unless the compressor is engaged. Refrigerant (R-12, or Freon) creates cooling when it is liquid at high pressure is sprayed and vaporized through the orifice valve into the evaporator. Besides the blend door blocking heat, later years also had a valve to block hot coolant to the heater when the AC is turned on. So, one box can hold the gizmos for both hot and cold.

Is the hose coming from radiator an isolated / separate refrigerant?

Not the radiator. There's a "condenser" in front of the radiator. The radiator cools the engine coolant; the condenser is a separate "radiator" for the AC system. Two AC hoses, one in and one out.


With the AC system at rest, AC not on, the charge equalizes throughout the system; it's a mixture of liquid and vapor R-12, refrigerant oil, at pressure. With the compressor on, pressures go a lot higher on the high pressure side, less but still pressure on the suction side.

For a better grasp on how the truck's AC system works, there's probably a ton of stuff that be found googling, and I think that there may be some here in the tech section.

 

[RobbieD]

So, if you're wanting to remove the AC. Once you are sure the system has no charge-
- you can remove the compressor, including any mount and drive brackets and/or idler pulleys
- you can remove the condenser from behind the grille
- you can remove the drier/accumulator
- you can remove the hoses which were connected to the previous items.
You could just leave the evaporator, or remove it but still have the big box on the firewall. Or score a heater only box, and remove the evaporator and have more room.

Some of the hose connections will be spring-lok, so you'll need the tools for those.

If you think you may restore the AC system someday, then hang onto all of the parts you remove, and cap the evaporator if you leave it in place.

Good luck!

 

[rusty ol ranger]

Is that compresaor any good?

 

[RonD]

AC is an option, a separate system, so can be removed partially or entirely, at any time without effecting vehicle operation

If you have ever had an air compressor you may have noticed how HOT the compressor gets, but when the compressed air comes out its COLD......WTF???

And thats AC, for vehicles and homes, and the same is used for refrigerators and freezes

Instead of air a liquid is used that can be compressed/heated and then be released to get an even colder temp than air could do

There are 6 parts
Compressor, has 2 hoses, one that sends out compressed liquid and one that brings in the decompressed liquid to be re-compressed

Condenser, in front of the radiator(no connection to it except bolts), it gets the compressed liquid which is very hot and some of it may have become a vapor/gas, condenser allows it to cool enough for all of it to be a liquid again

Expansion valve, or Orifice tube, Ford uses orifice tube, literally just a small hole that allows the high pressure liquid out at a slow flow, the size of the hole sets the amount of cooling, also acts as a filter
Orifice tube will be on one one port of the Evaporator, as high pressure fluid is released into Evaporator it cools it down, same as hot coolant heats up heater core
You want the AC to run at about 36 to 40degF on the cold side to avoid freezing water to the outside of Evaporator

Evaporator, looks like a small radiator, similar to heater core, its inside the Blower/fan housing in engine bay, ALL AIR going into the cab passes thru the Evaporator before going into the cab, heater core is in the cab so no connection

Receiver/drier, is to store the compressed or decompressed fluid, it can be on either side of the system, high pressure side or low pressure side
It also has desiccants inside that can absorb moisture from the fluid, the "drier" part of receiver drier
Because the fluid can get below 32degF water/moisture in the fluid could freeze and block the hoses/tubes
Anytime an AC system is left at 0psi pressure or hoses are left off longer than a few weeks you must put in a new receiver drier

The 6th parts are the pressure switches, there is a high and low pressure switch that will turn the compressor on or off if pressure gets too high or too low, too high will blow off hoses, too low will burn out compressor

 

[Josh B]

I think a lot of them, including mine, although the parts have the same names were upgraded at some point to use the newer type charge.
I've never been agreeable to just releasing the stuff but that is what so many do. Even the trucking company I worked for, when I started had 1250 tractor-trailers and when I left 2 years later had 1500.

If you didn't wish to just release it into the atmosphere they'd say to get a 5 gallon bucket filled with water and put the release hose into that, possibly just a stupid joke.

That's one thing has me draggin on my tear-downs, they are both fully charged and I haven't found anyone who collects it :/

 

[eightynine4x4]

Amazingly helpful thanks fellas for all the extensive info.
So I gather it’s possible to at least attempt to dispose of the old liquid/gas ..? I’ll call around. The bucket thing is funny but also maybe sad indeed.
What form of substance will I be expecting to fly / pop / spew / launch / squirt out of this system? I’m not one to just poke around and find out. I’ll have the plan first.

Thanks @RonD for the thorough parts rundown. I’m going to take a look in the bay to try to find all these segments. Definitely hadn’t realized there was this much going on.

It’ll be great to get it all removed though, and I’ll probably hold on to it all for some year when i can prioritize it. Although I could see that never happening. Anyways it sounds like it could free up a ton of space. Might need to rig up some caps and seals though.

 

[RobbieD]

Just venting the refrigerant charge into the air was the norm up until sometime in the mid-90's. I think that it became more tightly Federal regulated at that point, and a recovery machine had to used. The expense of the equipment and the increased regulations on refrigerant made a lot of the smaller shops stop doing auto AC work. Where I worked we did a lot of air, and we dumped a shitload of R-12 in the air. Just didn't know any better back then, but at least it got figured out that it was bad for the earth.

On my own stuff these days, luckily I have a local shop with a recovery machine that will pull the charge, and recharge it after I've worked on the system, for a fair cost.

 

[RobbieD]

What form of substance will I be expecting to fly / pop / spew / launch / squirt out of this system?

Done slowly with a gage set it can be vented mostly as a gas with some oil mixed in. I used to rubber band a plastic bag on the gage set yellow hose, barely crack open the valves, and then go work on something else for a while.

First find a service port valve, and push in on the Schrader pin to see if it's charged. If it's charged, see if you can find a shop with a recovery machine to pull the charge. Then you can open the system and disassemble and remove components.

 

[eightynine4x4]

Got it. If I have charge, I’ll keep this all installed and get the truck running again soon, then be ready to drive to a shop to have them pull the charge.

So the charge.. I’m testing like as I wouod when releasing fuel pressure on rail via schrader.. pushing in a little. Then maybe seeing what? Isn’t it just gas and invisible? Is it a sound I’m checking to hear?

 

[RobbieD]

I’m testing like as I wouod when releasing fuel pressure on rail via schrader.. pushing in a little.

Exactly. Give it a quick push; if it's a full charge you'll get a good spurt. Mainly vapor with some oil and liquid. Just be careful and make it a quick press.

 

[RonD]

Thomas Midgley Jr., the man that killed or maimed at least 100 million people over the years

He was at the forefront of Leaded gasoline, Ethyl gasoline, adding lead prevented pinging/knocking but was also very poisonous
In the 1920s many workers died or got very very sick from lead poisoning, Midgley also got sick and took a year off before coming back and extolling the virtues of Ethyl gasoline and how safe it was, he was vice president of the company making it
Still more workers died directly from lead poisoning, until better safety measures were put into place

Ethyl could be sold cheaper and at a higher profit than the current Ethanol blends that reduced pinging
"Ehtyl" came from tetraethyllead that was the additive to the gasoline, and sounded a bit like ethanol which was safer to use

Ethyl pretty much replaced any ethanol blends because of price for 40+ years, until the lead started showing up EVERYWHERE and caused all kinds of health issues

No, the lead in leaded gasoline didn't "lube the valves", lol, or do anything at all except reduce pinging and pollute the air
Older engines that ran fine on leaded gas, ran fine on unleaded

Then Midgly went on to develop CFC's (chlorofluorocarbon) aka "Freon" or R12
Also a bad pollutant
Which is why you shouldn't just release it from AC systems

Not sure if its Karma but Midgley contracted Polio in the 1940s
His mobility was impaired so he build a system of pullies and levers to help him in and out of his bed
He was found dead, strangled by his "invention" when things went bad, he was 55
Some say it was a suicide

 

[RobbieD]

^^^ Thanks, @RonD .

People (science, rather) has learned a lot. It does matter that we should try to do things responsibly.