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Bronco conversion to r134a?

2bet on Wed June 02, 2010 1:25 PM User is offline

Year: 1992
Make: Ford
Model: Bronco
Engine Size: 351w
Refrigerant Type: r12
Ambient Temp: non
Pressure Low: non
Pressure High: non
Country of Origin: United States

New here and need a some advice.

My truck has not been running for almost 18 mo and recently i finally got it running.
Refrigerant or oil vented out through the high pressure relief valve when the engine is warmed up.

Took it to the shop to have it check (50$) and they wanted 380$ for a r134a retrofit excluding the cost of the compressor if it is broken.
Refrigerant has been removed(by the shop).

Now i have an r12 ac system with no oil and refrigerant and im not sure if there is a problem with my compressor.

My question is, should i just try and get a r12 recharge or should i go for a 134a retrofit?
(i don't hear any good reviews about the local part store retrofit kit, so i would not attempt to)

Any help would be greatly appreciated.

2bet
Las Vegas, NV

bohica2xo on Wed June 02, 2010 1:35 PM User is offline

The first question is Dealer A/C, or factory A/C? Factory A/C used an FS10 compressor. Dealer installed A/C used an SD709 compressor.

Here in Vegas a retrofit will need an upgraded condensor to work well, along with the best airflow you can provide. The good news is the F series / Broncos have the space to upgrade the condensor, and the fan to cool it.

Your system still contains oil. Evacuating the charge only removed the refrigerant.

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.

2bet on Wed June 02, 2010 3:38 PM User is offline

Thx for the reply bohica.
I would have to say is FS10 based on pics i googled.

I was thinking of getting the A/C back before it reaches 120*, so any help would be a lifesaver

Edited: Wed June 02, 2010 at 3:41 PM by 2bet

mk378 on Wed June 02, 2010 4:59 PM User is offline

Likely the relief valve popped after the condenser overheated because the fan clutch is shot. Just because the fan goes around and the engine doesn't overheat doesn't mean you have enough airflow for good A/C.

bohica2xo on Wed June 02, 2010 5:57 PM User is offline

Ok, the system is probably OEM. Look carefully at the compressor, and see if it is a ford part, or a replacement. A coat of paint usually indicates a used part...

The issues now are the high pressure event / cause, and the relief valve re-seating. Most of the time a relief valve that old does not re-seal when it opens. It may close most of the way, but many leak.

Look at the condensor. The OEM replacement for that vehicle is a serpentine part Like This which has small passages. A failed compressor can clog half of the condensor capacity without being obvious. This of course can lead to a high pressure event...

It can be very hard to determine the condition of a serpentine condensor internally. It may look fine with half of the passages clogged. It is usually not worth flushing one. If you have a tube & fin condensor with round tubes, it may be flushed - but it has less capacity and does not retrofit well.

With an unknown system the place to start is the orifice tube. It is the filter for the system, and can tell you a lot by what is on or in it. Pull it, and post pics if you can. The next stop on this truck is to see if you can remove the accumulator from the evaporator. If the nut & tube are frozen, you may be replacing the evaporator. Best to find out now, before you order parts.

The compressor can be bench tested if it looks like a good part. A new FS10 is under 250 bucks from AMA.

Worst case, condensor/accumulator/evaporator/compressor - under 475 bucks in parts. For a whole new system.

If the fan clutch is more than 3 years old, it is tired - especially here in Vegas. Make sure the fan shroud is installed, and the radiator air path is clean. Replace the fan clutch if it does not wake the neighbors on a cold start...

There are some other, smaller parts. An HPCO switch for legal retrofit. High quality 134 adaptor fittings (AMA has the STEEL ones). BVA100 oil for the system. Flushing any re-used component.

As for "beating the heat" here... looks like 105f for the weekend.

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.

2bet on Thu June 03, 2010 9:55 AM User is offline

Quote
Originally posted by: mk378
Likely the relief valve popped after the condenser overheated because the fan clutch is shot. Just because the fan goes around and the engine doesn't overheat doesn't mean you have enough airflow for good A/C.
I was doing a radiator flush without the fan clutch attached when i hear a loud noise, thats when i see mist coming out from the pressure relief valve.

Quote
Originally posted by: bohica2xo
Ok, the system is probably OEM. Look carefully at the compressor, and see if it is a ford part, or a replacement. A coat of paint usually indicates a used part...
The issues now are the high pressure event / cause, and the relief valve re-seating. Most of the time a relief valve that old does not re-seal when it opens. It may close most of the way, but many leak.
Look at the condensor. The OEM replacement for that vehicle is a serpentine part Like This which has small passages. A failed compressor can clog half of the condensor capacity without being obvious. This of course can lead to a high pressure event...
It can be very hard to determine the condition of a serpentine condensor internally. It may look fine with half of the passages clogged. It is usually not worth flushing one. If you have a tube & fin condensor with round tubes, it may be flushed - but it has less capacity and does not retrofit well.
With an unknown system the place to start is the orifice tube. It is the filter for the system, and can tell you a lot by what is on or in it. Pull it, and post pics if you can. The next stop on this truck is to see if you can remove the accumulator from the evaporator. If the nut & tube are frozen, you may be replacing the evaporator. Best to find out now, before you order parts.

The compressor can be bench tested if it looks like a good part. A new FS10 is under 250 bucks from AMA.
Worst case, condensor/accumulator/evaporator/compressor - under 475 bucks in parts. For a whole new system.
If the fan clutch is more than 3 years old, it is tired - especially here in Vegas. Make sure the fan shroud is installed, and the radiator air path is clean. Replace the fan clutch if it does not wake the neighbors on a cold start...
There are some other, smaller parts. An HPCO switch for legal retrofit. High quality 134 adaptor fittings (AMA has the STEEL ones). BVA100 oil for the system. Flushing any re-used component.

As for "beating the heat" here... looks like 105f for the weekend.

B.
I can safely say is OEM.
I hope is just the a faulty release valve.....that would be the cheapest and easiest to replace huh.

I'll try and dismantle system and take some pics as soon as i find time.

I found a friend who has an air compressor, so i guess i'll be able to flush my condenser and evaporator.

Would you care to explain how to do a bench test on my compressor? didn't wanna to flush everything and realize that i have a shot compressor.

72* now and climbing

Edited: Thu June 03, 2010 at 9:56 AM by 2bet

bohica2xo on Mon June 07, 2010 3:44 AM User is offline

The procedure for a bench test is HERE

An air compressor can get the flush out of a system, just be sure the air is dry - usually not hard here in Vegas.

Running without a fan would explain the popped relief. If that is what did it, then your system is probably in decent shape - you know the compressor can make over 400 psi.

If you plan to convert, flush the compressor with oil as shown in that link, and flush the balance of the system with solvent. Make SURE you get all of the solvent out of the components. This can take a LOT of air. Search this site, there is a lot of flushing information on 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.

2bet on Mon June 07, 2010 9:52 AM User is offline

Thx yo!
Back to more reading

Edited: Mon June 07, 2010 at 9:53 AM by 2bet

2bet on Tue August 31, 2010 11:23 AM User is offline

I finally decided to replace the whole ac system.

Appreciate if sponsor/members would advise me with the total cost.

Thx in advance.

bohica2xo on Tue August 31, 2010 1:22 PM User is offline

Basically all the parts you need are on this page:

1992 Ford Bronco 351 V8

The Blue orifice tube should be used. The dryer should be matched to the fittings on the vehicle - threads or springlock. The condensor is a serpentine, and has enough capacity for 134a use if you have a good fan. Be sure to adjust the cycling switch if you go to 134a.

If you want the hose set, you should call AMA @ 602-233-0090 They can get you a hose set, they just don't list it on that page.

The evaporator can be replaced without too much effort. It is probably packed with debris anyway - my 1993 F series gets that way here in vegas.

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.

2bet on Wed September 01, 2010 9:20 PM User is offline

Thx bohica2xo.

Appreciate it!

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