Automotive Air Conditioning Information Forum (Archives)

jbrown on Sat July 30, 2011 3:34 PM

Year: 1992
Make: Ford
Model: F150
Engine Size: 4.9L
Country of Origin: United States

I apologize for the length of this!

The A/C on my '92 F150 has been inoperative for years due to a seized compressor, and I'm considering bringing it back into operation.
This is a dealer installed system at the time the vehicle was bought new, with a Sanden SD709 compressor (direct mounting), factory style accumulator/drier, blue orifice tube (no expansion valve), and a tube and fin condenser. The hoses have crimped fittings at the evaporator and accumulator ends, but hose clamps everywhere else.
The system has been repaired once before years ago by the dealer due to no cooling. The repair cost was around $800, so I think the compressor was replaced at that time, but I don't remember for sure.
The last failure was a sudden seizure of the compressor, which then caused the clutch to self destruct. I removed the clutch at that time and installed a different sized belt to keep the truck usable. The system held pressure for at least a year after that, but now it has no pressure, so there is at least a small leak (probably a big leak now after the intervening years).

I think the reasonable way to go is to replace the compressor, condenser, accumulator, lines, flush the evaporator, and convert to 134a. I hope I can source the parts for $500 to $600. Any more than that and I'll just do without A/C. I have a gauge set and a very good vacuum pump (surplus semiconductor process pump), so I can handle evacuating and charging with 134a. Since the pressure is already gone, I've looked at the orifice and there's just a small amount of metal particles and surprisingly (at least to me!) small fragments of what looks like gasket material. No black goop or film. So I think the evaporator can be easily flushed.

The questions I have are related to what new components to get.
I assume there is a compressor more suited for 134a than the SD709 that will be a good physical fit? Or is the SD709 fine for 134a?
I assume the old hoses are junk (especially for 134a), and that new barrier hoses won't clamp on well like the existing hoses (that's why I'm planning on a new condenser).
I assume a modern condenser will be more efficient as well as having real fittings.

Buying replacement parts listed for the dealer installed air doesn't seem like the right way to go. The listings I see for dealer installed air show a different accumulator than mine, show an expansion valve that I don't have, and I can't find any listings for equivalent hoses.

Should I buy factory air parts, since I'm replacing everything but the evaporator? The accumulator I have now looks just like the factory air part.
Will a factory air condenser fit without too much trouble?
Could I then use factory air replacement hoses?
I certainly don't want to put a factory air type compressor in that's going to do the black death teflon thing. Are the replacements for the FS10 compressor immune to that now?
The factory air connections to the compressor look completely different from the SD709 connections I have now, so I assume I need to coordinate the compressor selection and hose selection. I don't know which way to go here, pick a good value compressor and spend a lot getting hoses made, or pick a compressor I can use with off the shelf lines?
Places around here that I've asked about making A/C lines give me very high ballpark quotes (would kill my $500 to $600 budget), so I'd probably try to find an online outfit if I go that route.
Will factory air parts I buy from ACKits work well with 134a?
Are there 134a specific parts I should buy?

Keeping it R12 would require that I have a shop do at least some of the work, and around here that just won't happen within my budget.

Am I being too optimistic with my target cost range? If it weren't for the clamp on hoses, I'd just replace the compressor and accumulator and give it a shot, but every post I read says the hoses are likely to leak and barrier hoses will pop off the barb fittings and/or not seal.

Thanks for any comments and suggestions!

-Jim

bohica2xo on Sat July 30, 2011 8:07 PM

I actually own an F150 with the same system. Can be a challenge getting the right assortment of parts sometimes. Wrench connections on the compressor, a springlock on the OT connection. Suction side accumulator. SD709 mounted under the PS pump on the driver's side of the 4.9 Hose clamps on everything else.

The condensor is a tube & fin, which was adequate with R12. If you look up a replacement on this site, you will find a serpentine for the OEM system. But if you look at the 1994 condensor it is a 6mm design. Both replacements have springlock connections.

The 709 replacement from AC kits will be fine with 134a. I would keep the 709. Replace the tube & fin with the later condensor. The hose from the new condensor springlock to the OT springlock should be the OEM hose, so that one is a no-brainer. The suction line from the accumulator to the compressor should be just fine unless it is damaged. That leaves one "custom" hose - from the compressor discharge to the condensor springlock. Not a difficult hose to have made up.

The accumulator, OT, and evaporator in your truck are factory parts for reference.

I much prefer the SD709 to the FS10. I have about 160k on my 709 right now. The OEM condensor should fit easily. Ford went from R12 to 134a in the middle of the 1993 model year. In 1993, FS10 trucks were 134a, and 709 systems were R12.


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.

jbrown on Tue August 02, 2011 10:07 AM

Thanks for the info bohica2xo.

I'll probably go for a condenser for a '94 then, and stick with a 709. It looks like there are on-line places that will make up hoses for around $20 over the cost of the hose and fittings. That's way better than the ballpark $100 a hose local places quote me! I think they are just trying to convince me to have them do the whole thing....

I guess I should then look at charge amounts for a '94? I haven't checked to see if there's any significant difference between '92 and '94.