AC compressor replacement

[Traveler]

Okay so you may think it is silly to work on AC in March and so do I, but worse yet I bought the parts in Febuary.

This also applies if you want to do a R12 to R134 conversion.
During reassembly just throw your conversion fittings on, and back the cycling switch out about 1 to 1.5 turns.
You don't have to flush the system unless you want the R134 to cool as good as the R12 did.

So the front seal on the FS-10 compressor has been leaking and throwing oil for a couple years. It finally got to the point it stated smoking one day.
I guess that means it is done.

Well I bought the stuff, might be a waste of time but I tried to do it right.

New, not reman compressor, accumulator, and orfice tube. Those things with a system flush are required to recieve warranty if needed.

So I started by evacuating the system the proper way with a recovery machine.
No most of you cannot do this, so let me just say a hose frequently just comes loose, or gets cut.

So we stick the machine on and hit recover, it weighs how much freon was taken out of the system. In a perfect world, that would tell us how much to put back in.

The machine recovered .38 pounds, so I assumed there is some missing.

[Traveler]

You can see the old compressor here till mounted in place.

You can barely see the clutch and see the tan rusty color from the heat.

[Traveler]

Here is the accumulator, or reciever drier, or filter drier.

[Traveler]

Okay after we have removed the accumulator, and compressor. You need to pull the orfice tube sorry I did not get a good pic.
I had a friend helping me and got easily distracted.

So we removed that stuff to be able to flush everything.

We also need to remove the lines at the rear AC to flush through them as well. The round silver disk thing right on the hose there is the expansion valve. I pulled the hose off there to flush through from both directions.

[Traveler]

This is the orfice tube.

Old one on the left came out in pieces. Not un common to be that way.

New one on the right.

[Traveler]

Next the compressors

one thing you need to remember is when installing a new compressor rotate it a few dozen times by hand before starting the truck up, that clears the compressor of oil, if there is too much oil there it can break the compressor before you ever get to run it.

[Traveler]

New Accumulator drier.

[Traveler]

This is the part where we flush.

We have to do it before installing the new parts, we do not want to risk contamination in any of the new parts.

They have different flushes. I work for a chemical company so I have a wide variety.

I use heptane. It is like a degresser, very flammable, but evaporates fast.
Heptane is what they put in the old Coleman lantern fuel, not the white gas, or unleaded.
I have recomended people to use laquer thinner.
They sell flush and it smells just like laquer thinner.

So anyway you see the can, next to that the funnel, then the aluminum can on the right.
It has a regulator on top of it. being that heptane is flammable compressing it makes it like a bomb, so you use the lowest pressure you can to push the stuff through.

You hook an airline to the can, and pressureize it. the hose has a rubber tipped blow gun on it. Very simple to operate.

I flushed from the rear AC to the front, then through the Evap, then through the condensor, and the last hose that runs from the evap to compressor.

After you push the product through, use a plain airline and blow through some more, that will purge all the flammable vapors.

[Traveler]

Here is where the orfice tube goes.

This is a spring lock fitting. You are suppose to replace all the O-rings as you go.

[Traveler]

Okay system is flushed.

Now put your new parts on.

After the system is closed up you need a vacuum pump to pull a vaccum on it.

Now you only need to pull a vaccum for 15 minutes, but I usually leave it on for a couple hours. It will remove air, and moisture from the system.

After the vaccum. Then we add oil. I put in 4 ounces which should be more than enough for this system.

Next is charging. There is no set charge, or weight.

If you replace a hose and a new one is a foot longer than the old one then you need more freon.

I of course was trying to charge it in March which is tough since the outside temp is cool anyway.
I put in 2 pounds and stopped that was enough to make it cool air, cycle the compressor and keep the windows defrosted.

The recomended way of charging is.

Rev the engine to 1200-1500 rpm
Turn AC on max, front and rear
Stick a thermometer in the vent
Slowly add freon until the vent temp stops dropping.
If you see the temp start to rise stop you are fully charged.

I think I got it. If you have questions feel free to ask.

[MOFOCO1]

I just had to have mine replaced as well. The bearing went out and it started squeeeeeeeeeeeeelin' like a stuck porker!
Clutch got so hot it glowed red. It took Autozone 4 tries to finally get me the right omne, oh what #### they put me thru last 2 weeks.ht compressor with the correct 7 groove clutch pulley. Freakin idiots!! I will expanded on this later. I have always been one of their best supporters but the new crews there suck!!!!!!!!!!!!!!!!! http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/sad.gif ?http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/sad.gif ?http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/sad.gif ?http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/sad.gif ?http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/sad.gif ?http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/sad.gif
Gotta go get 3.5 hrs of sleep, before work...Later....Mo

[JohnDeStef]

Traveler, excellent write up!

I have received my Cent, and am deep into figurging it all out... what needs done and what the priorities are.

Right now I'm doing the AC and am going from R12 to 134.

Can anyone help me identify the expansion valve? The numbers on it do me no good. Where/who do I get one from???

THANKS A MILLION GUYS! The trucks tying up some valuable shop space here in Ft. Myers Toyota's garage.

[Audra]

uhm leave it r12, wish I had on mine. http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/wave.gif


It cooled much better when it was r12.

[Traveler]

If you can get me a picture of your expansion valve I can probably come up with a part number, you can take it out and go to the parts store with it, maybe, just maybe you will find someone smart enough to give you the proper one.

Is there a reason you want to replace the expansion valve? or just doing it because you are suppose to?

Yep R12 will cool better, but the sources are dying off very quickly.


Let me see if I can find a pic or two.

[heatmiser]

The last time i replaced R12 with 134A we got the condeneser from a 95 or 96 because it is a :duel pass system and it cooled fine here in Phoenix, just not in the back as no :duel air i think we bought all the stuff from a 7.5 to get all the hoses had help from a friend who works for ford. http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/new_Eyecrazy.gif *http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/new_Eyecrazy.gif *http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/new_Eyecrazy.gif

[adrianspeeder]

Quote[/b] (Audra @ Sep. 07 2005,16:25 )]uhm leave it r12, wish I had on mine. http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/wave.gif


It cooled much better when it was r12.
I suppose you have a large supply sittin around?

http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/Oo.gif

Adrianspeeder

[JohnDeStef]

It was the rear ac that wasn't working, and we found alot of metal shavings in the oriface tube. *We replaced the compressor, dryer, and evalve, also flushed the system, replaced all the orings and filled it with 134, and put on a new serpentine belt. *I paid for parts, $220, and painted an Odyssey decklid trim panel & front bumper to cover the labor.

I'll post the part number for the rear evalve soon, for future member endeavors. *Proair couldn't help with part numbers to use at Pep Boys or Autozone, but they could sell/ship me a valve!http://www.supermotors.org/getfile/230589/fullsize/nutkick.gif

[BJS]

Quote[/b] (blackfordtruck @ Sep. 08 2005,09:43 )]
Quote[/b] (Audra @ Sep. 07 2005,16:25 )]uhm leave it r12, wish I had on mine. http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/wave.gif


It cooled much better when it was r12.
I suppose you have a large supply sittin around?

http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/Oo.gif

Adrianspeeder
yeah have a case sitting in the closet not to mention that w/ the correct license (which I have) I can go to napa & pick up whatever I want.

[Traveler]

That is a cheap AC repair.

R134 will get as cold as R12 did, but the head pressures are so high usually the compressors are short lived, atleast on a system dseigned for R12

The rear expansion valves I have seen have always been a pretty standard and basic, just hard to get parts guys to open the book and look.

[JohnDeStef]

I cannot get the ac to blow cold. *We've evacuated and refilled the system 3 times, and replaced the blue oriface tube with a red one. *There was still a small amout of shavings on the blue tube when removed yesterday.

The rear unit blew at 70 deg. and the front at 80 deg..

The underhood temps are very high. *I'm thinking about adding a 10 inch condensor fan, and insulating the evaporator box, and dryer. *

The lines for the rear ac run right near the passenger exhaust manifold, but.. the rear ac is colder than the front... http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/rock.gif *I'm also going to insulate those lines.

<sigh>

[Traveler]

Well first what are your pressures?
Just a guess, the low side should be around 35psi, high side 300psi

How much are you putting in? mine was right about 2 lbs, but I have done others close to 3

Try clamping off the heater hoses gently with a vise grips to see if the temp drops any, it could gain you 10-15 degrees pretty easy.

Does the fan clutch work? You can run water over the condensor, and if it starts cooling, the condensor is bad or the fan clutch is bad. You should not need to add an electric fan.

If you have pressure readings that will help a ton.

Feel the line fight after the orfice tube, is it cold?
now feel the outlet from the evap, coming out of the firewall, it should be the same temp when properly charged, is it warmer or colder?
If outlet is colder than inlet, you are over charged.
If inlet is colder than outlet, you are under charged.

How much oil did you use? you didn&#39;t add more than a couple ounces did you?

Did you check your vent temps with the truck running?

http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/biggrin.gif

[Traveler]

and insulating all that stuff is a waste of time, it will not gain you any noticeable differences.

It isn&#39;t like heat, the amout it gains or loses traveling to the evap does not effect it.
It operates off of pressures, and pressure release.

The pressure is built by the compressor, as the freon passes through the orfice tube it expands, as it expands it gets cold.

If the condensor, or hose was plugged or restricted somewhere, you will have a cold spot right behind the restriction.

[BJS]

Even w/ the water going through the heater you should still be seeing temps 15-20 below intake air temps for the dash registers. I&#39;ve been playing around w/ the a/c in my DD and noticed that on vent setting the air coming out of the vent is aprox 8-10* above outside temps. so theoretically by bloccking it off you can gain that extra cooling but you have some other problem.

The fact that you&#39;re catching derbis on the orifice tube says that there is garbage in the sytem somewhere, condenser, evaporator, or failing pump take your pick. Which side of the oriface tube was the derbis on?

As for insulating lines makes no sense the air box is logical and ford did heat shield the air box on mine and most of the later models. My guess is that when the banks kit was installed on yours the insulation got destroyed as it&#39;s only a reinforced alum sheet.

[JohnDeStef]

I&#39;ll print out your questions and take &#39;em with me tomorrow when we tackle the ac again. *There&#39;s ALOT of great ideas in there&#33; *http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/xyxthumbs.gif

Today&#39;s upgrade day for the oil and shocks. *Amsoil 5w-30 w/ filter is going in. *Rancho RS9000X shocks are on all corners. *I&#39;ll be playing with the settings in the coming days. *And I&#39;m gonna do a postings search for what ya&#39;ll are running your Ranchos at.

Thanks guys.

[NOTLIKLEY]

I have attempted to write up a response here a few times. Maybe this *can help&#33;

R-12 vs R-134a, *(these are referigerants not "freon", Freon is just a brand.) *R-134a has a better heat of rejection than R-12, and a better proformance curve at all temp ranges with the exception of low temp applications *(below 0ºf)

The myth that R-12 is better than R-134a *is incorrect, R-134a is better.
Those of us in the refrig. trade are just sick of the multiple products on the market because retrofitting is a nusiance. But again I emphesize that when properly done, performance of R-134a is far better.

The most common problem with both referigerants, is incorrect charging procedure.This is not hit or miss&#33;&#33;&#33;&#33; The importantance of this charging procedure I can hardly emphasize enough.I am from the low *temp referigeration field for 25+ years, I have been teaching CORRECT charging procedures for 3 years, as a consultant for a engineering firm, * and have recently become an owner of a automotive repair facility.

That being said. *If you have a Thermostatic expansion valve(s)--TXV it will work equally as well for R-134 as it did for R-12. *Determine the "engineered" charge wheather you are using 12 or 134 (this is usually in the engine compartment, if you don&#39;t know ask someone here to advise.) If 12 is your option WEIGH the charge into your unit exactly the amount indicated, you&#39;ll need a digital scale.

If you are doing a 12 to 134 retrofit follow the procedure for flushing described by Traveler. The charging procedure will hardly differ however the correct charge will now be 15% less.

Increasing the size of the condensor will possibly mask an overcharge --changing the condensor isn&#39;t necessary. *

Reason: *

If your system is a TXV, the excess referigerant is stored in the condensor. Because the condensor is the place where heat is rejected and if the charge of 134 is 15% less; any form of a over charge will reduce the capacity for cooling ("heat of rejection"-- we really dont speak of cooling.)

If your system is a fixed meetering device (not TXV, any color oriface tube) and the system is overcharged, excess referigerant is stored in the evaporator. Hence poor cooling or in ability to absorb heat is the result.

FrigiCold is the manufacturer for our *rear evaporators and can help you with the charge, information measuring the aftermarket referigerant lines or any modification will additionally modify the amont of referigerant.

In conclusion let me reiterate: *charge is critical, both referigerants&#33; *If you retrofit 12 to 134 charge is to be reduced to 85%. *Don&#39;t guess-- reasearch the charge and do it right.
You will be happier. * http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/bluboomteamenforcer.gif

[JohnDeStef]

Wow, impressive reply, thank you very much for your expertise.

We are in a disscussion over which oriface tube to use... red or blue. Blue came out of it when we switched to 134, but our parts supplier insists it calls for red.

Right now, with no gauges or tools, the lower side of the oriface is cold and the upper is hot.

[Traveler]

Any idea how much you put in?

Lower side, which is past the orfice tube, now the upper you are checking the outlet of the air box right, right before it goes into the big can? (reciever drier)

Notlikley is exactly right, Charge is critical.
We face two problems, nobody ever said how many pounds or ounces to put in one of these things. If I was guessing I would bet the flunky at Centurion that did it had no clue what he was doing way back when he did it. The shop foreman probably said, uhmm charge it till it&#39;s cold.
And we also have a dual system, front being orfice tube, and rear being expansion valve. So an expansion valve stuck open or closed can be misleading as to what the problem really is.

[adrianspeeder]

Notlikley, AWSOME info&#33; http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/chrs.gif

Adrianspeeder

[BJS]

Mine actually still has the sticker added on the core support that says how much more the additional system requires.

I&#39;ll look tomorrow and report back.

[JohnDeStef]

Well I put in 3.3lbs and then bled the low side until the vent temps started dropping. I ended up with the coldest temps at 40 on the low side and 300 on the high side.
I believe I have either a bad fan clutch, condensor or clogged condensor. After running water over the condensor and having 1700rpms, the vent temps drop to 55, and the pressures to 30/200... right where we want &#39;em. Soooooo I think I&#39;ll price a fan clutch or install a pusher fan. I&#39;m really not into doing a &#036;300+ condensor job.

Or will a bad condensor bring down the rest of the system?

[Traveler]

if You dropped 100 psi by running water over the condensor, then you do need to move more air across it.

Sad part is, 300 might be all the better the truck will do until you are driving it down the road.

300 is not ideal, but common.

[BJS]

A bad condenser will bring down the rest of the system.

I had stickers on mine saying how much extra to add but they&#39;ve peeled off so I can&#39;t tell you and that would have even given you the amounts for 134a http://www.fourdoorbronco.com/temp/iB_html/non-cgi/emoticons/sad.gif

Both are going to cost you roughly the same but realize that depending on how warm the engine was it may not have gotten hot enough to trigger the fan clutch to engage. With the truck cold & just sitting in what I&#39;m guessing is upper 80 to 90 degree weather you should be able to turn the fan clutch with a fair amount of resistance. But you won&#39;t see optimal cooling from the fan clutch until it everything gets good and hot. And when it does kick in you should be able to hear the difference when you idle up the engine. On my truck I know mine works but I have to be in stop & go traffic w/ the A/C running before mine kicks in and then you can hear it over the diesel and it definately takes away from the power when accellerating.

Oh fan clutches should be right around &#036;100 which is going to be in the same ball park as the pusher fan if you get a reasonably large one. Though realize that if your clutch is going out then you aren&#39;t going to be getting adequate engine cooling from slimply the elec fan in shouth FL.

You may try getting a large shop fan and pointing it @ the front of the truck when you&#39;re checking the A/C system as that will simulate actually moving. If you do alot of sitting in traffic then you might want to look into the auxillary pusher fan for when you&#39;re stationary.

Fan Clutch Diagnostics:
The fan clutch is a hydraulic viscious coupling. The fans fail most frequently due to the hydraulic component leaking out. This leaves high friction surfaces in conctact that wear out quickly w/o the fluid to carry away the heat leaving the fan operating at lower that desired performance. The fluid when it leaks tends to draw dust and derbis onto the clutch assembly as an indicator of the leaking of fluid. There is not enough fluid to ever notice puddle or leak under the vehicle.

[BJS]

Found my sticker for some reason I was thinking it was on the unit in the back not under the hood.

Mine says 4.5Lb of r134a with 2oz of oil for a system charge.

[Traveler]

4.5lbs, wow that is a bunch, I have right at 2lbs in mine and I think it is very close to correct. Anthing else I would add would just increase pressures and not lower vent temps, so I stopped.

I know not every vehicle is the same, but that is a big difference. over twice as much.

[BJS]

yeah I was rather dumbfounded when I found sticker & read it also considering that the stock charge if I remember right is like 1.6lb