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Where do I begin ('87 Bronco / R134A) Pages: 12

slawson2000 on Sun April 29, 2007 4:11 PM User is offlineView users profile

Year: 87
Make: Ford
Model: Bronco
Engine Size: 302HO
Refrigerant Type: R134A
Ambient Temp: 110+
Pressure Low: ?
Pressure High: ?

Where to begin? I have an '87 Bronco that was switched over to R134A about 6 or 7 years ago ($1200+). To make a long story short, I guess there was not enough airflow over the condenser and the pressure got so high something popped after a couple days of usage. Got it fixed, popped again. The shop wanted to add a fan for $400ish and I had enough and have done without since. I can not do without any more. Anyway, now I have electric fans and the shop wants another $1100 to fix it (nice huh?). This time I figure I'd like to try it myself.

So, where do I begin. Is there a way to test components? Where is a good place to buy parts, any good tool recommendations (considering I do not do this for a living)? Any recommended upgrades?

Where do I begin?

Chick on Sun April 29, 2007 7:16 PM User is offlineView users profile

Do you know why the AC isn't working now? A leak that needs to be found? Do you know the pressures? even static? You can jump the cycling switch on the accumulator to see if the compressor comes on, but don't run it any longer than to see if it work. Changing to R134a will involve flushing the system, finding and fixing the leak(s) adding back the proper amount and type of oil, and recharging about 80 to 85% of the R12 charge with R134a. Check out the tips and FAQ page for flushing procedures and vac/charge procedures. A "NEW" fan clutch will be a must. You can get all the tools and parts right here at Ackits.com (you will need a new O tube and accumulator) and you can get a very nice DIY'er starter kit that will allow you to fix the system yourself. Much cheaper than you've been paying for your AC service. And of course any questions, post them and we'll help you along..Hope this helps..

-------------------------
Chick
Email: Chick

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Freedoms just another word for nothing left to lose

mk378 on Sun April 29, 2007 9:26 PM User is offline

It sounds like a hose blew out. See if there is any pressure left at all. You can begin by finding the service ports, unscrew the plastic cap and very briefly press down the valve like a tire valve. If nothing comes out, all the refrigerant is gone. Inspect the hose leading from the compressor to the condenser.

A proper retrofit requires adding a high pressure switch to shut down the compressor in case of abnormally high pressure. Also likely the pressure got too high because your fan clutch is worn out.

You will need at least a gauge manifold, vacuum pump, and can tapper to do basic repair and recharge work.

slawson2000 on Mon April 30, 2007 11:04 AM User is offlineView users profile

Let's see if I can cover all these questions.

My AC is not working because

Quote
there was not enough airflow over the condenser and the pressure got so high something popped after a couple days of usage. I would assume there is a leak somewhere or a pressure relief valve blew (?).

I am not changing to R134A, it was already swapped over.

I do not have a fan clutch, I am running electric fans (Flex-a-Lite #251).

I will take a look at the tips/FAQ pages. Thanks

The hoses look in tact. There is no pressure (at all).

Again, it was swapped over by a reputable (and expensive) A/C shop, I assume it was flushed of R12. I would like to think that there was a high pressure switch added, but apparently not.

Have some patience with me, I can turn wrenches, but this is new territory. So first I need to find the leak. What is the best way to do that without refrigerant? I understand the benefit of decent tools, but $300? I am not complaining, I just have to do a little cost analysis. What parts should I look at replacing? Is the parallel flow condenser worth it? BTW, I live in Las Vegas.

TRB on Mon April 30, 2007 1:18 PM User is offlineView users profile

Not really an easy way to test for a leak without using some refrigerant. You could add some nitrogen and do a bubble test. But that is not going to show the smallest leaks that can be present.

This site has some great people helping with the questions. So feel free to ask away as most are kind hearted and just want to help.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

88Vette on Tue May 01, 2007 3:52 AM User is offlineView users profile

Quote
Originally posted by: TRB
Not really an easy way to test for a leak without using some refrigerant. You could add some nitrogen and do a bubble test. But that is not going to show the smallest leaks that can be present.



This site has some great people helping with the questions. So feel free to ask away as most are kind hearted and just want to help.

That is for sure 100%!
:-)
This place is the best at helping a newbie and ackits are the best for parts and prompt service!!





-------------------------
Location:Houston, Texas

bohica2xo on Tue May 01, 2007 4:27 AM User is offline

You probably opened the pressure relief valve. These have a reputation for NOT re-seating properly after they open.

One of the requirements for a proper 134a conversion is a high pressure cutout switch. The shop that did your conversion should have installed one...

The pressure relief valve is the horizontal cylinder on the compressor in the picture below. It is threaded into the discharge fitting, and has a hex on the end. A replacment may be hard to locate locally. If your valve is bad, it will leak when you try to pressurize the system, out of the hole in the end with the hex.



.

Where to start? With a decent set of gauges, and some simple tools. My recomendation would be to invest 300 bucks in the DIY Starter Kit, and do the whole job yourself. Your repair could be as simple as replacing the relief valve, and the dryer. Once you own the tools, the next repair is even easier.


B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

Chick on Tue May 01, 2007 6:14 AM User is offlineView users profile

Here is a pic of various PRV's. They ciome in different sizes, but I have really only seen two thread sizes, Metric and standard. If you can't find a new one, junk yards are full of them.. Just ask if you can take one off a core or you can send it to me and I'll match one up for you as a last resort..
The pics may be a little small as they were taken when Bohica was teaching me how to re-size pics..




-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

Edited: Tue May 01, 2007 at 6:17 AM by Chick

slawson2000 on Wed May 02, 2007 11:03 AM User is offlineView users profile

Thanks for the starting point. I'll get some 134a and start looking for leaks. Is soap and water a good way to check? I'll also be keeping an eye out for a good gauge set. Any while I can appreciate good tools, is there a way to use a hand vacuum or a cheap vacuum pump (hf or similar)?

Thanks

slawson2000 on Thu May 03, 2007 5:14 PM User is offlineView users profile

Started into the diagnostics. Here is what I found. After I jumped the pressure switch, the compressor clutch locked in and the compressor turned freely with the engine running with no noises or anything for about 3 seconds then I disconnected the jumper and it stopped. I repeated it again just to make sure. I assume that means the compressor is OK - tell me other wise.

As far as a HPRV, I think mine is gone. Not like it blew out, but like it is not there. There is a hole with threads on top of the compressor - nothing else. Am I correct?





Also, I found this fitting between the compressor and condenser to be only finger tight.



I think I have found my leaks. How does one go about finding a replacement HPRV and what should I replace while it is apart? The compressor part number is Ford f5lh-19d786-aa. Where should (and how do) I install a high pressure cut off switch and where can I get one of those? I can not find anything other than the R134a Adapters that is not stock.

Thanks in advance.

Edited: Thu May 03, 2007 at 5:17 PM by slawson2000

bohica2xo on Thu May 03, 2007 5:41 PM User is offline

Your HPRV is missing. So are some other parts. The shop that worked on that system did you no favors.

The finger tight fitting should be replaced with a combination HPCO switch / service port assembly. Depending on the fitting size there are two:

HPCO / Service fitting 1/4"

HPCO / Service fitting 3/16"


Your system has been open to atmosphere for as long as the HPRV has been missing. You will need to replace the dryer, and flush out the old oil. The compressor should be flushed with fresh oil, as detailed HERE The compressor in the pics just happens to be the same as the one you have.

The rest of the system needs to be flushed as well. PAG oils are hygroscopic, and if exposed to atmosphere for very long they become waterlogged. Given the sloppy work on your system, there is really no way to tell how much (or what kind of) oil is present. It should be flushed to bare metal, and recharged with the correct ammount of 134a compatible oil.

The two valve stems on the compressor manifolds are service valves. The dust covers are missing from both valves. It is possible that the valves were not in the proper position, and caused your high pressure problems. For normal operation, they should be all the way open, and "backseated". They have a seat that prevents stem leakage when they are open all the way. They should be turned counter-clockwise facing the end of the shaft, untill you feel them "seat".

I would go to the local "pull your own" junkyard, and pick up a couple of dust covers, and a couple of HPRV's. If you have the facilities, your old HPRV can be welded shut. As long as you have installed the HPCO, this is perfectly safe. Look in This Thread for more HPRV information, and pics of a welded one.


B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

slawson2000 on Thu May 03, 2007 7:04 PM User is offlineView users profile

Great info so far. I guess in hind sight the system has been open for years. What is the best oil for the compressor? I take it you should just flush the compressor with oil - correct? The dryer is just a bolt in piece - correct? Anything else I should get, replace, flush, clean?

I will get that switch. What about an in line filter? Is that a good idea?

One sad thing is that the shop that did the work is supposed to be one of the best in Las Vegas. All my friends have had great success with them. I do not know what happened with me.

The dust covers were (are) there I just had them off for the picture. I was thinking instead of welding it shut, maybe find a bolt/plug that can seal it shut? What thread size is it? Any ideas? The bone yards around here are pretty slim on just about everything.

Keep that advice coming!

bohica2xo on Thu May 03, 2007 7:50 PM User is offline

slawson:

I would run BVA 100 in that compressor without hesitation. Most of the parts you need, including the oil are available from the site sponsor AMA. Even with UPS charges, the parts will cost you less than they would here in town. I do not know if Tim (AMA) can get the HPRV as a new part or not.

I will look around and see if I have a known good HPRV. You are welcome to it. I weld them up because there is no simple way to plug the hole. A bolt will not work, since the valve has a shoulder & groove for the O ring seal. I try to hang on to the ones that seal, and only weld the bad ones.

A new dryer, an HPCO, some BVA 100, an orifice tube and some O rings are about all you really need.

You will flush the compressor with the oil you plan to use, so buy a little more than the system needs.

The balance of the system should be flushed with a suitable solvent, and dry air t oremove the old unknown oil.

Check the service valves. It is possible that the high side valve is nearly closed. This would blow the HPRV, even though the high side gauge reading was at a reasonable figure. A technician that was not familar with the valves could overlook this, and would blame the condensor for high pressures when it left the shop.

You should also replace the fan clutch if it is more than a couple of years old. I see it all the time here in the desert, since the engine does not overheat "it must be OK". A ford OEM part is dead @ 60k miles or so. A white box (pep boys, autozone, etc) replacement sometimes does not make it to 20k miles.


B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

slawson2000 on Fri May 04, 2007 12:59 AM User is offlineView users profile

A welded one would be perfect. I am of the theory that less is more.

Are the service valves the ones on the back of the compressor that should be all the way open?

I do not run a fan clutch any more. After the shop told me I needed more air flow over the condenser while stopped in traffic, I upgraded to one of these:

Flex-A-Lite 295 Fan

and wired to to come on at 60% with the a/c.

So I take it I do not flush the new dryer, or condenser, just the parts left over.

What is the general consensus about an in-line filter and how to test for leaks?

Thanks again (this is awesome).



bohica2xo on Sun May 06, 2007 8:20 PM User is offline

slawson:

I have a welded HPRV from an FS6 you can have. What part of town are you in?

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

slawson2000 on Sun May 06, 2007 8:43 PM User is offlineView users profile

Eastside. Out by Trop and Boulder. Where are you?

BTW, Thanks.

bohica2xo on Mon May 07, 2007 4:49 AM User is offline

I am a bit closer to the center of town - 89103

I will send you an e-mail.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

slawson2000 on Thu May 10, 2007 1:40 PM User is offlineView users profile

Got the email, sent one back. Did you get it?

BTW, picked up a vacuum pump today. Gauges on the way.

bohica2xo on Fri May 11, 2007 4:02 AM User is offline

Steve:

I sent you a reply, hope you got it.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

slawson2000 on Mon June 11, 2007 11:03 AM User is offlineView users profile

Thanks for the part. I am now trying to get the parts ordered.

slawson2000 on Fri June 15, 2007 9:43 AM User is offlineView users profile

The parts arrived. I have some BVA oil, the HP switch kit, accumulator, blue orifice tube, o ring kit and a welded up HPRV. So my plans are to the new parts on the system, flush the evaporator and condenser while it is apart, then try and charge it up.

Any hints, tricks, suggestions for me?

How much BVA do I need to add to the system and where would be a good place to do it?

Thanks in advance...

slawson2000 on Fri June 15, 2007 3:46 PM User is offlineView users profile

I need a good estimation of how much oil to add to my system. I blew out the condenser... nothing came out but air. My lines were pretty much clear. I replaced the accumulator (don't know how much it holds). And I blew out the evaporator, don't know how much blew out there.

How many ounces should I add? I put about 3.5 back and currently have it under vacuum. I need to go to the shop again, so cracking the system to add (or remove) a little is no biggie. I think the system holds about 7oz from dry.

Please help....

HECAT on Fri June 15, 2007 4:07 PM User is offline

If you flushed, and the components are dry, compressor drained, new accumulator, and o-tube; you will need the full load of oil, if it is 7 ounces. If you just blew with air, the oil coating the insides of the heat exchangers is still there and we can only guess how much. If this is the case, someone else will give you their professional "guestimate".

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

slawson2000 on Fri June 15, 2007 7:31 PM User is offlineView users profile

Well, I ended up draining the compressor and putting 7oz in. Everything else was "blown through with a compressor... hopefully it is right. Now I am going for the 80% rule and see how the head pressure does in this heat... 104* and climbing.

slawson2000 on Fri June 15, 2007 10:16 PM User is offlineView users profile

This about wraps up this chapter... I continued the saga here:

Tell me if I did it....

Thanks for the help....

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