Expansion Valve Replacement

[tgates]

My 85 GT has dealer installed "factory" AC. I have no suction pressure at the compressor. After troubleshooting with a good AC guy I am now looking at replacing the expansion valve. While I am at it, I plan to replace the associated hoses.

I would appreciate any advice you all may have regarding the valve replacement. Is dash removal necessary or is there sufficient access without going that nightmare? The evaporator does not leak but I assume I should change that as well if I have to pull the dash.

Also, I would appreciate hearing about a good source for replacement hoses.

Thanks in advance for the help.

Tim Gates
Baton Rouge LA

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[KevinVarnes]

I am not familiar with the dealer installed A/C component locations. The expansion valve is normally somewhere on the firewall and accessible from the engine bay, but I can't say for sure on your car. You would have to follow the high and low side hoses from the compressor to the evaporator to find the valve.

In addition to what you are planning I would also replace the accumulator/drier and any o-rings and seals you can get to. I normally source most of my A/C parts from RockAuto, but there doesn't appear to be a lot available for the dealer installed A/C systems. You will have to do your homework on parts and assume any part listed is for the factory system unless it specifically states it is for the dealer installed system. The factory system uses the Nippondenso compressor whereas the dealer installed system uses a Sanden compressor.

Do you plan to retain the R-12 refrigerant or change over to R-134a?

[erratic50]

Personally I have hate relationship with the (GM style btw) pancake compressors often used on the dealer installed air kits. Ive had a cars with one and worked on a few over the years. My experience was that the clutches go bad, the compressors lock up, etc— with a lot more frequency than with the factory ford stuff.

For that reason unless I’m a concourse restoration guy (at which point I’d rip the dealer AC out entirely) I’d swap everything out to make it a factory AC style installation.

They work better on R12 but they work OK on 134A. If you switch to 134A get the 134A pressure switch also.

On my 1985 build absolutely everything AC and heat related was gone. The car was used as a road racer before I bought it as a well abused in many ways but minimal rust and straight low miles roller. I’ve bought all the factory stuff and am going together with the type of parts it had when new. You have to search for some of the 85 and older hoses, etc, but they are out there.

[tgates]

I elected to stay with R12. Bought a new never used HR980 compressor (with threaded fittings...rare) plus a new clutch and dryer. I bought my car new and the dealer installed AC system was essentially trouble free for 33 years. I figured that was good enough from a reliability standpoint.

But all is not perfect. The hoses are old but they hold pressure so I will get to those in time. I want to get the pair going to and from the evaporator while I am in there doing the control valve.

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[erratic50]

Good luck getting it back together!!

[tgates]

The AC is all back together... except I need a new expansion valve. So close...

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[chevelle21]

The AC is all back together... except I need a new expansion valve. So close...

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Where is your valve located? my 85 also has dealer AC. I assume its behind the dash? I removed my compressor and lines last year for my engine swap. Only thing I didn't touch was the unit behind the dash so I'm curious if that's where your valve is.

[85stanggt]

I don't know about the dealer installed A/C, but the factory installed A/C did not have an expansion valve. Older A/C systems used an orifice tube that is inserted in the line where it hooks up at the firewall. You do not have to pull the dash to replace this. (Again, not sure how the dealer installed A/C is set up, but should be similar).

The orifice tube has a tiny hole that serves as the restriction in the system. If this gets clogged it will prevent flow. But, the compressor should still be able to pull the low side down, even with the line restricted. Is there any pressure differential in the system when you put gauges on and run the compressor? I am not convinced the orifice tube is your problem.

[Ourobos]

Liquid line has orefice tube, your 85 has no expansion valve. If there's a blockage and new lines and dryer didn't solve it, it's likely in the evaporator behind the dash.

[KevinK]

I looked up the dealer installed AC in the Ford book. It lists the base part numbers but the detailed listing is missing most of the AC parts. I believe the expansion valve is 19848. Likely a very generic part and you may have better luck at Napa. Actually, I see Rock Auto lists it for $12.00.

So much for all those guys saying there was none on the Dealer Installed AC.