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Compressor Testing?

Parts were ordered on 8-14-06.........I got the package from today/8-18-06. And, I picked up the A/c tool (Shamaal's pic) from Harbor Freight.

Won't have time to work on the Explorer for awhile.

Anyway, I gotta make sure the parts are correct........the inked numbers, stuck onto the parts, don't correspond to the invoice numbers..........crossing my fingers that they sent the correct stuff.

Aloha, Mark

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Me? I'd flush the condensor while I am at it.

I called, and went over the numbers.......the delivered stuff, are the correct parts. So I plan on working on it next Sun/Mon.

I plan to change out the parts myself and hook it all up. Then, take it down to get it professionally vacuumed and R-134a re-filled. I asked, "How long was the window of opportunity, as the accumulator would be hooked up, but air would be in the system (though all hoses connected)". I don't want to ruin the new accumulator.

He said, "Get it re-charged, as soon as possible.........but, no more than a week."

Is it true (up to a week)? Or should I be worried, if I don't get it done w/in 24 hours?

Aloha, Mark

The accumulator dessicant only holds a few drops of water.... and sucks it from the air. Wait til you are close to being ready and put it in last.... his advice is good, but I'd do it in 24 hrs in a humid environment.

ps. it is not "vacuumed", it is evacuated. Nothing is vacuumed like a carpet, just all the air is removed. HUGE difference. Imagine is a huge dome was placed over your house and all the air slowly sucked out until there was a total vacuum. Would you consider your carpets vacuumed in that scenario? Obviously no, and this is what evacuating an AC system is like.

Sorry, last weekend I spent..........cutting down two trees in the yard.........And, with the end of Summer almost here (Labor Day Weekend)......I guess, this project will have to wait.

Spend some time w/ family before school starts know how that goes.

Aloha, Mark

*******UP DATE********

Spent about 12 hours yesterday (9-10-06) working on the Ac replacement parts project........what a PIA, removing the evaporator was.

Why so long? Well, I did get side tracked.......checked the battery and added water........R/R the passenger side spark plugs (access was great).........and noticed that my brake caliper slide pin was making it's way out by itself (ohhhh nooooo). Wasted about 45 min on removing an elec. connection plug (w/ additional red lock along......doom on the FORD engineer). And about an hour on a part that disappeared.......found it hung up on the frame rail......just "tired, I guess."

I'm almost done..........just gotta get the accumulator back in.........I need to get down to the parts store.......will be back later to up date.

Also, gotta contact my Ac guy..........see if he'll be available to evac and re-charge it later this afternoon.

Aloha, Mark

Just in time for the cold weather :D


I wanted to ask about A/c oil (PAG100)..........from the Haynes book it says:

Compressor oil:
drain old compressor oil and mesaure
If <3 oz......add 3 oz.
If 3-5 oz.....add that amount plus 1 oz.
If >5 oz......add only that amount

Evaporator oil:
Add 3 oz to the new evaporator

Accumumator oil
Remove schrader valve, drain old oil and measure.......add equal amount plus 2 oz.


I figure that the old parts have some (very little) oil left coating the walls of various components. So, went like this:

Drained......not even 1 tablespoon came, I put 4 oz in the new compressor.

Again, not even 1, I just added 3 oz.

Took off the schreader and drained about 1-1/4, I'm planning on putting in, I guess 3 oz.

So, a total of 10 oz of new oil for the system (w/o the condenser change) I didn't/couldn't find a TOTAL OIL amount, listed for this A/c system.......I'm worried about over doing it with oil.

Question: Does 10 oz. sound correct? Or, do you have a different reccomendation?

Aloha, Mark

PS>>>>BTW.....the oil out of the components looked orange (dye I guess). And when the oil was taken out of the accumulator, it was "muddy on the bottom (1 oz)" with a floating oil layer on the top. Twelve year old oil (I guess), is that common?

Re-charge appointment at the shop is set for tomorrow (9-12-06/afternoon). So, I'll oil and replace the accumulator, tomorrow morning. Then button up everything just prior to taking it down.

7 = 9 oz oz is the oil load for your system. Instead of putting in the evaporator a better place would have been in the accumulator. What will happen now is the oil will gravity feed backward through the orifice into the condensor. As the refrigerant is a darn good solvent, no harm done.

I don't recall if you changed the orifice, I didn't see it in the list. The orifice has a screen on it that would catch any particles clogged in your system. It's good practice, particularly on an old system like yours to inspect and clean or replace as necessary. Remember, you now have a fair amount of oil at that junction. So be prepared for a spill if you disconnect. Add new oil to replace any lost into the accumulator.

Yes I've seen the oil cloudy as you describe, I attribute it to breakdown of the dessicant. There is an orange fluorescent dye used for cooling leaks. I don't recall seeing it in freon systems though, back when I did this professionaly I used an electronic leak detector. An early dye may have been orange. If fluorescent, then it's a dye. Glacier 991 may know. The other possibility is rust if the accumulator rusted through.

After buttoning up, spin the compressor by hand a couple of times with a 10 mm wrench to distribute the oil. Don't do this if the system isn't closed.

Good luck, keep us posted.


Thanks for the, I'll just put 2 oz of PAG 100 in the accumulator and that will bring the total to 9 oz of new oil......for all my parts changing.

As for the orifice tube.....yes, it's new and was checked.....since I had good access to it.

And, I think it's fluorescent dye (for leak detection)......actually, I had some green and some orange stuff on different parts, that is why I asked......just couldn't figure green sometimes and sometimes orange.

Aloha, Mark

I'm back from the shop..........the good new is, I don't have a leak. Tech said everything, A/c wise, is working. Good pressures and more than the 150 psi difference between hi and low side.

The bad news is, the temp only dropped about 10-15 degrees below the ambient air temp. Tech said, it's a possible issue with the, "blend doors," mixing warm air w/the cold A/c air.

I did spray water to clean off the condenser.........really, hardly not a thing came off.

So, I gotta work on it somemore...........will be checking the blend doors next.

BTW.............Tips for the install:


Those bolts on the bottom side of the evap housing box.......remove the inner fenderwell to get at them.

Remove the heater hoses at the firewall........gets you better working room.

No need to disconnect the elec. connector block (the one w/small red plastic lock) or the vaccum tubes from the interior side.


As for the compressor mounting, use anti-sieze where bolts (steel) are going into aluminium bracket.


Check your parts. I called the supplier and was told via the part# that everything was correct. Sorry, check the physical size too. The delivered accumulator (aluminum) was taller. I had to remove the old bracket just to get it to fit in the same general location. Now, there is no bracket to hold it steady, not a good situation, IMHO. I didn't return it, as I already had put the new oil in it, before I discovered the error. Not to mention, I bought it via the internet.


This thread was helpful (along with the A/c stickies above):

Points to remember:
Greenies for every O ring.
Nylog lube for O rings.
Only, "finger tighten the plastic," valve pressure switch on the accumulator.

As in the link...........too bad I didn't remember seeing the oil being placed into the accumulator.

I figured that since I had to remove the schrader valve to get the oil out........that the oil would have to go in the same route. Yes, I did it w/ a syringe.........not the best way.

Aloha, Mark

PS..............My math must be off somewhere.........I bought an 8 oz bottle of PAG100 oil and used it all up (and I spilled some)..........but the numbers add up to 9 oz.............oh well, to late to worry about it now.

Does the tube coming out of the evaporator to the accumulator feel cool, maybe even have condensate on it? If so I would agree with the tech.
There are known blend door problems, but I'm not sure if they are applicable to your year. On mine (91) I can open the glovebox, squeeze the sides, drop it down and gain access to the blend control cables.

I said:

So, I gotta work on it somemore...........will be checking the blend doors next.

I forgot there were some leaves stuck to the old evaporator when it was removed..........huh??? Where did that come from. Last night, I was looking for an easy way to remove the cowl and seeing if I could clean it joy, there. I guess I'll have to attack it problem from the inside.

Not to mention it could be a blockage (or partial blockage) within the duct work, too.


Thanks for the tips...........I'll be looking at everything that you mentioned.

Does the tube coming out of the evaporator to the accumulator feel cool, maybe even have condensate on it? If so I would agree with the tech.

Haven't tested it, yet. Funny you mentioned that, I read that last night (Haynes manual):

The pipe (thinner tube) leading from the condenser outlet to the evaporator should be cold, and the evaporator outlet line (the thicker tubing that leads back to the compressor) should be slightly colder (3 to 10 degrees F). If the evaporator outlet is considerably warmer than the inlet, the system needs a charge. Insert a thomometer in the center air distribution duct (see illustration) while operating the air conditioning system- the temperature of the outputiar should be 35 to 40 degrees F below the ambient air temperature (down to appromimately 40 degrees F).


There are known blend door problems, but I'm not sure if they are applicable to your year.

Yes.....I saw that in other threads. I think that it's mainly for the early 2nd Gen..........though, anything is possible. So, I'll be looking into it.


BTW, the tech pulled a vacuume on the system (evacuated the system) for a short while (not the 1 hour, frequently stated on the web). I asked him why NOT an hour? His response was, once it goes down to 29 (something) it's done, can't do better than that, no matter how long vacuume is pulled. So, I guess his, "professional machine" is just better/faster? Is that true?


Yesterdays Bill:

AC Evac/Recharge ------------- $39.95
Refrigerant 1 lb. --------------- $38.00
(only charged for 1 lb, cause he recovered 1 lb last time)
Haz/Shop Supplies ------------- $2.00

Total ------------------------- $79.95

With cold weather approaching fast, perhaps, I'll have to wait for next summer (if I don't fix it soon). And, this time I'll be looking for a shop that speciallizes in automotive A/C.

Aloha, Mark

PS.............humours side notes: (well, maybe not so funny)

Yesterday after working so hard and double checking that everything was back in place, I got behind the wheel and tried to start it............NO JOY.........OHHHH NOOOO!!!! Ok, keep calm.........was I hearing the fuel, OK press that button under the floor mat.........OK, she started right up after that.

And...........looking on the motor by the distributor........there is a condensor looking object, a fried wire coming off of it and a connector from the wire loom that ends w/ nothing attached. Easy, right? Well, I go to the various auto parts places with the part in hand (everyone thinks is some sort of ignition or distributor condenser or capacitor)............but, nothing in the coumputer.

Ended up at FORD DEALER, guy says its a radio condensor...........a little less that $10.........he adds, "Do you have radio trouble?" My response, "No." He counters, "Than, you don't really need it, you could save yourself the money."


Yes it's a radio condensor. Condensor is what they used to call capacitors at the dawn of time, the Brits still call them that. With the cylinders firing at the rate and frequency that they are and at the high voltages that they do, a capacitor shunts any noise off the +12 volts line. The effect on radios or sound equipment is a buzzing noise.

Occasionally the capacitors short to ground internally and burn up. In the old days (points and coils) the condensor was replaced whenever you did a tune-up. With today's electronics, noise on the +12 can cause really weird problems. The computer should also have line filtering that keeps this from being a problem. I'd replace it if the opportunity arises or you start getting flaky computer errors. Not having it will not make anything go bad.

Regarding pulling the evacuation. When the pressure drops, any water present will boil. The longer you hold the vacuum, the more water will boil out. Some people I know actually heat the lines with their hands or heat gun to hasten the process. I do not have any studies as to how long it takes, 1 hour is common, I've heard of overnight. The idea is that the water will not vaporize instantly, it takes time.

That's the reason people wait. Having said that, I'm not going to say the tech is wrong. In my opinion, you pull the vacuum long enough to evaporate and remove any water present. With a new accumulator with new drier material it's may be immaterial and superstitious to hold for a long time.

Glacier991 is the experienced expert and may have an opinion.

From everything I have read that Schmaal posts, I'll concede that HE is every bit as much as an expert as I am. Maybe more.

Anyway, he is exactly right. The reason you evacuate for so long is to remove all water vapor. Your AC tech should go back to school, as he clearly doesn't understand.

However, and as Schmaal noted, with a new accumulator with a new dessicant pack, you are fine.... just not old school way of doing it.

I'd like to know your pressures... what IS the low side and what kind of cycling are you getting?

If I remember said something like 250 HI and 30-40 LOW (I could be wrong about the numbers)......I was more interested in the 150 difference between the two readings.

I tought about cycle times: It was 4 secs.

BTW.....I still gotta grab those hoses and try feeling for the difference in temps.

Got any ideas: On how those leaves entered the duct work?

Aloha, Mark

OK...I grabbed the pipes:

The smaller diameter pipe, connecting the evap to condenser (w/orifice tube inside) was cold.....condensation noted on it.

The large diameter pipe connecting the evaporator to the compressor, and the pipe connecting the evap. and accumulator (top side) were both cold.........condensation noted on it.

Can't tell the difference in temps (all cold). Hope this helps.

Aloha, Mark's about mid 50s F, outside today......and we just had hail falling w/ the rain.

Good, the problem then, as you surmised, is that you are not getting airflow across the evaporator or it's being mixed with the heater air. Either a blend door or something stuck in the path (leaves?).

You may be able to drop your glovebox and see the door cables.

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. a plan.

I'll be able to look further into it...........on Sunday/Monday.

Aloha, Mark