95 Bronc with a compressor failure. It sat up about a year and when i put it back on the road the AC Clutch failed so I replaced it in the hopes that maybe it was just a clutch.

With the new clutch is made progressively louder racket so I stopped using it until the other day when the new clutch failed (I briefly turned it on).

I think it is time to replace the compressor.

In researching the compressors I noticed that there are varied makes so I have a question as to which brand compressor to buy. Here are my options:

• O'Reilly - Motorcraft - Assume FS10 - 283.99
• Autozone - Ready Aire - FS10 - 235.99
• Autozone - Compressor Works - FS10 - 179.99
• Autozone - Compressor Works - SD709 - 247.99
• Autozone - Denso - FS10 - 259.99
• NAPA - Visteon - FS10 - 301.00
• NAPA - (unknown) - SD709 - 409.00
• ACKITS - Unicla - FS10 - 236.35

Do I get the FS10 or the SD709 (I assume Super Duty)? How can I identify which compressor my Bronc came with from the factory (FS10 or SD709)? I live in Texas so strong cooling is imperative.

Should I even consider buying a remanufactured compressor (the ones listed above are all new)?

I typically stay away from getting parts from Autozone because I have found the parts that they sell to generally be of poor quality.

 

It sounds like the compressor has failed internally. You'll have to do more than just replace the compressor, as the entire system will be filled with debris that must be removed. If the condenser is a "parallel flow" type, you should seriously consider replacing it. Accumulator and orifice tube replacement is also necessary.

If the AC system is factory it will have the FS-10 (Nippondenso), I believe the SD-709 (Sanden) was used with dealer installed AC.
I can say for sure that the Visteon, Unicla and Motorcraft (Visteon, I believe) compressors are good quality. I doubt the quality of the Ready-Aire (Four Seasons) unit and I share your concern about the Auto Zone compressors. I don't have any actual experience with Compressor Works.

Good Luck

 

Thanks for the reply.

I had already planned on replacing the compressor, accumulator, orifice tube and condensor.

My only concern about doing the job myself is cleaning the old lines. I am planning on buying ac cleaner specifically designed for the application but I am wondering if there is some machine that a shop would have that might do a better job. Do they just introduce the solvent and then blow them out with compressed are or do they have a closed system that circulates and filters the solvent?

My other question is how much oil should I introduce after I vac down the system? Do new compressors come pre-oiled?

 

Good plan.

There are various methods used in shops for flushing depending on the equipment they chose to buy. You can read about some of them here:
Automotive AC Information Forum - ACKITS.COM
Since you got a price from ACKits, you may have already seen that.

Assuming you didn't have a Black Death failure, you can flush the remaining parts of your system yourself with a solvent that evaporates quickly and doesn't leave a residue. (Lacquer thinner, alcohol, toluene, etc). There are specific flushing solvents available that work very well, but depending on your budget, they can be pricy.
The key to DIY flushing is to have a good volume of compressed air available to dry the pieces thoroughly.
Avoid the cans of aerosol flush available at the chain parts stores. It usually leaves residue that can be hard to remove. There are also non-aerosol flush liquids that seem to be water based (FJC brand comes to mind), avoid these as well.
If you had a Black Death failure, the repair is actually easier. Just replace everything except the evaporator.

The oil can be hit or miss. Some comps come with a full system charge, some come just with a small amount of shipping oil. New compressors "usually" come with a full charge of oil, but not always. I always just completely drain the oil and add the known proper amount/proper weight/proper type of oil to the system. It eliminates the guesswork if the mfgr isn't specific about the oil shipped in the unit. The amount and type should be on the AC spec tag under the hood. Usually 8-10 ounces of PAG-46. Don't forget to add UV dye.

I appears that you are really doing your homework on this repair, so I won't get into seals, evacuation, charging, etc.

Good Luck!

 

I typically get way more information on a repair than I need because I am not a professional mechanic and don't have experience doing these repairs frequently (I find professionally that experience doing the job is the most important factor to success).

I very much appreciate your advice on the types of solvents because I was planning on using the aerosol. I have ample compressed air so that shouldn't be a problem.

I will further investigate the kits from ACKITS because I only referred to this site for component pricing.

Related to seals, the compressor will have new seals/ o-rings and I replaced the main hoses about 2 years ago but what other seals should I be aware of? Given that I will be replacing compressor, condensor and the accumulator I think the only seals that I wouldn't necessarily be replacing would be whatever connections might be to the evaporator.

 

I like the way you approach fixing your car. You can never have too much information to make good choices.

ACKits sponsors an excellent DIY AC forum. The link I posted was to a forum section on flushing. Lot's of good info, Browse around the rest of the forum while you're there.

You will be replacing many of the o-rings/seals with the new parts. Just replace any other orings for insurance against future leaks. A complete O-ring kit is about $8. Don't forget the oring under the cycling switch, that one can be a "gotcha".

Shameless plug for ACKits: Tim and Company (Arizona Mobile Air) use the products they sell on their website. Tim will not sell a product online that he wouldn't use on a customer car. They are one of my preferred suppliers.

 

I am almost done with the new component installation but where is the orifice tube?

I can't find it in my manual. From my GM experience they are typically installed around the accumulator but I don't see it on the Bronc.

I'll find it one way or another when i get back to the project later today but I thought i would ask the question just in case I get some help ahead of time.

 

Look inside the accumulator inlet tube fitting (the smaller tube), it should be there.

If not, Ford integrated the orifice into the liquid line on some vehicles. I don't recall the Bronco being one of them, but you never know. Remove the liquid line (small, condenser to evaporator line) and blow through it. If you feel a restriction, the orifice is in the line. If it flows freely, the tube should be in the evap inlet.

There is a chance that the old tube blew down into the evaporator inlet tube. It's not common, but does happen. When the compressor fails and plugs the orifice, the high side pressure can skyrocket and blow the orifice down into the pipe. The only way to fix this is to replace the evaporator. (You might cut the tube near the bend, remove the orifice then weld the tube back on, just a thought.)

A word of caution; Don't uncap the accumulator until you are ready to install it. Install it last, just before you evacuate the system. If you can't evacuate right away, remove and recap the accumulator. The desiccant can quickly become saturated just by humidity in the air.

 

I completed the installation and recharged the system according to the fluid capacities that the guys at O'Reilly looked up for my vehicle:
11.5 Ounces of Pag 46
33 Ounces of R134a

(for those that are repeating the same repair, plan on removing the evaporator to clean it out. I had a heck of a time just trying to blow cleaner through it so I took it off to thoroughly clean it. I would highly recommend this to anyone completing this repair).

It cools very well at speed but doesn't seem as cold as it should when I am idling (of course it has hit 100 here in Houston the last couple of days). My concern is that I might have too much oil in it or I over or undercharged it with r134a (I put in 3 12oz. can and just vented some of the last can to make approx. 33 oz total).

What should the temp be at the vents at idle?

What should my low and high side pressures be at idle?

Should I take out about 2 oz. of oil and vac down and recharge the system (do I really risk anything with 9.5 oz. of oil vs. 11.5 oz)? Could a 2 oz. difference in r134a make a difference?

I have thoroughly appreciated your assistance throughout the process.

 

11 oz of oil is a slight overcharge, but won't hurt anything.

Did you find the old orifice tube? If it's in the evaporator tube, that can cause issues.
Your lack of cooling at idle is probably caused by poor airflow over the condenser. How old is the fan clutch? If more than 5 years old, it's probably weak. AC performance at idle/low speed is the very first place a weak clutch will manifest itself. The engine won't notice until it gets really bad.

BTW, You did pull a 29.5" vacuum on the system for 30 minutes before charging, didn't you? You didn't mention it. If not, that's your problem, there's air in the system.

If you did pull a vacuum,
Connect the gauges again and post your High and Low pressures at 1500rpm, Max AC, High blower, doors open after about 5 minutes
If the High side pressure is more than 2.5 times the ambient temp, mist water from your garden hose over the condenser.
- If the High side pressure drops like a rock the fan clutch is bad or the outside of the radiator is plugged with debris.
-If the pressure drops slowly or very little there may be an internal blockage..

 

x2 on the fan clutch, I've had several fail at 150k to 200k miles. Electric radiator fans really help A/C performance it hot city driving. Great info on this thread. Could be a stickie !
regards
rikard

 

I definitely pulled a vacuum down on the system for more like 45 minutes before charging and it was right on 29.5.

As I indicated, I charged with approx. 33 - 34 oz.s of 134a (one of the cans contained the UV dye just in case (I would never use leak seal in case you were wondering)). For those novices (like me) reading this later, the first 12 oz.s goes in pretty quick and the remaining refrigerant goes much slower so give it time.

I contemplated the fan clutch as it has probably been 7 or 8 years since I last changed it so I'll run the misting test to verify.

A few additional tips for those reading after the fact:

• If you are the least bit apprehensive, you should consider renting a vacuum pump and recharging the system yourself (assuming you have a set of gauges - I got a cheap set from harbor freight for $50). This is really the easy part. I ended up renting the pump from Autozone but they return your deposit in full when you return it.
• If you pull the evaporator be prepared for some rust on the screws towards the bottom of the housing. One of mine was so rusted out that I had to use a pair of vice grips to get it loose (and it is a bear considering how little hand room their is towards the bottom). There is also one bolt that needs to be removed from inside the cab (you can get to it without removing anything else).
• As indicated earlier, be careful of the solvent that you use to clean the system. The non-aerosol solvent that I got from O'Reilly was supposed to be rapidly evaporating but wasn't (I'm sure it would have boiled off when I pulled a vacuum down on the system but I also expect that there still would have been a residue). It was almost like pouring a can of oil into the system which is one of the reasons I decided to pull the evaporator off of the vehicle. I ended up using lacquer thinner and it worked great as it evaporates very quickly.
• Be sure to closely look at and compare the accumulator to the old one when you pick it up (you do need to replace this). The one I originally picked up was almost right but the mounts were offset from the factory original by about 10 - 15 degrees which prevented it from matching up.
• You'll need an A/C - Fuel line spring release tool to disconnect the high pressure line coming from the accumulator (and where the orifice tube is accessible). You can pick up a set of these for about $10 (I picked it up from Advanced Auto).
• The orifice tube can be a ways down the high pressure line so get a good pair of small long nose (with a thin long reach). I didn't have a pair that would fit so I ended up having to bend the very tip of a small nail gripped by a pair of vice grips to rig an extraction tool.
• You should consider replacing the main A/C hose when you have the system broken down if yours is very old. I had replaced mine last year so I don't remember what I paid for this but since you have the system broken down, you might as well.
• You should plan on replacing the condensor because I can only imagine how difficult this would be to get clean considering the process that I went through to clean the evaporator. If you don't, I would strongly suggest putting an inline filter in place because it could protect your new compressor from debris left over.
• Finally, don't buy cheap components to save a few dollars. I paid extra to get a new Motorcraft compressor (turned out to be $310 from O'Reilly and I had to make an effort to get it from them because their system initially indicated that it was not available). I plan on keeping my Bronco forever and don't want to have to redo this repair any time soon considering the expense involved. I ended up paying about $550-$600 in parts for this repair because I wanted it done right. You can do it cheaper but you get what you pay for.

 

dwg999, my bet is on a weak fan clutch.
Excellent writeup, Sir!!! Did you ever consider writing Tech publications for a living? I can think of many Tech publishers that need writers who have completed more than 8th grade. You're a shoo-in.
BTW, Everything that you did to your system, with the attention you paid, would have been $1500-2000 or better, if you had a shop do it.

I won't quote dwg999's entire post, but...that is one that should maybe be a sticky! Well written and straight from the successful experience of an AC newbie!! Not just the "yammering on" about how things "should" be done by some usual poster like me. After reading all of it, I want to send some customers his way.

 

lsrx101,

Thanks for the compliment.

I really just wanted to provide a thread that would help out other individuals in my position before they start the repair. I know this isn't an exception for this site but I just wanted to contribute.

This is one of the more useful sites that I have found for repairs and I very much appreciate it.

 

Which you did very well. Thanks for your contribution.