Ford C350 Dual Air - trouble

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bohica2xo
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Re: Ford C350 Dual Air - trouble

Postby bohica2xo » Sun Mar 03, 2019 2:23 pm

Looks like the replacement part for the Centurion is a Piccolo now

http://www.ackits.com/cond-f-series-94-96-dealer-94-98-yj-383-320-319-7626
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slawson2000
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Re: Ford C350 Dual Air - trouble

Postby slawson2000 » Sun Mar 03, 2019 5:40 pm

I think the Centurion may have a piccolo in it now.
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I looked into the TXV and saw one elastomer bit. That was it. Otherwise very clean. I did not remove it as it was encased with some sort of goop assumed to control condensation. It looked like it would be a PITA to get it off. I think it should be fine.

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So the plan would be to blow out the rear lines while the system is apart and then reassemble with new parts.

Do you see an issue?
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Re: Ford C350 Dual Air - trouble

Postby bohica2xo » Mon Mar 04, 2019 9:44 am

Plan sounds ok to me. Obviously that plastic made it all the way from the compressor to the back of the vehicle - through the condenser. A great example of why we say flushing is a good idea.

How much oil was present at the TXV?

The insulation on the lines & the TXV is called Presstite. It is a cork / butyl rubber tape that is used to insulate the valve & the control bulb for proper operation. If you need to remove it, you can cut or tear it away, but it should be replaced if you do.

Your condenser appears to be a plain tube & fin. One path, multiple passes. The important difference is the header on the other end of the condenser. A Piccolo has a header tube, that allows several pathways all at once. This slows the refrigerant down in the individual tubes. The piccolo also has smaller tubes - about 6mm

As condenser manufacturing has moved to the newer types, I suspect that the old single path style is simply not made any more. The tooling to make a Piccolo or Parallel Flow unit is cranking out OEM stuff by the ton, and an agile manufacturer can repackage a standard core with the appropriate connections & brackets easily.

I have seen aftermarket vendors advertising flat tube parallel flow condensers for the post-92 F series, but frankly the bracket attachments look pretty shabby. The Piccolo that AMA lists is a quality unit.
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slawson2000
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Re: Ford C350 Dual Air - trouble

Postby slawson2000 » Mon Mar 04, 2019 1:10 pm

I figured there would be something back there as there was plastic in the orifice tube as well. While it was apart I was going to blast the rear supply line (?) both ways with shop air to try and remove anything that is still in the line.

It had a little (emphasis on little) oil back there, but not nearly as muck as the orifice tube. Then again, the AC has not been used that much, and recently only about 5-7 min. Maybe not enough use to flow back there? Not sure exactly how the expansion valve works.
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Re: Ford C350 Dual Air - trouble

Postby bohica2xo » Mon Mar 04, 2019 1:23 pm

Overall not a lot of oil in the system. There is flow at the rear TXV anytime the compressor is running. Usually there is some oil built up in the rear system if the rear blower has not been running.

If you get the lines cleared out then you have a pretty much oil free system. Something to know when deciding how much oil to put back in when you reassemble it.

The TXV is wide open at room temperature. When you start the system refrigerant will flow in the rear unit until the sensing bulb that is clamped to the rear evaporator suction line (under the presstite tape) tells the TXV that the suction line is someplace below 40f. Then the TXV closes down the flow. If the rear blower is shut down, it takes only a little refrigerant flow to keep the rear evaporator near freezing - which is what the TXV does. Turn the blower on and the TXV will open and modulate flow to hold the evaporator temperature. A rear system is never really "off" unless it has a solenoid valve.
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slawson2000
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Re: Ford C350 Dual Air - trouble

Postby slawson2000 » Mon Mar 04, 2019 2:29 pm

I guess that will be the next big question... how much oil and how much refrigerant.

I guess the oil will be somewhat dependent on what comes out of the system. I'll see what I collect upon disassembly. Not sure about the refrigerant...
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slawson2000
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Re: Ford C350 Dual Air - trouble

Postby slawson2000 » Sun Mar 10, 2019 3:26 pm

Well, working on getting this together. Pulled the compressor and there is no oil draining from it, at all....

I pulled the drier, drilled a hole in it and it drained about 2.75 oz.

The replacement hose, a UAC HA 10407C was about a foot short between the drier and the compressor and does not fit.

The UAC compressor CO 35109C came with a 8 groove pulley while the truck takes a 6 groove.

The compressor clutch was indexed 90 deg out so the wiring does not fit.

The new condenser went in fine.

I did not install the new drier and plugged up the open hoses.

Just having fun.
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Re: Ford C350 Dual Air - trouble

Postby bohica2xo » Mon Mar 11, 2019 9:15 am

Yeah, aftermarket installs can be a puzzle like that. I have a 1993 F150 with dealer installed A/C. Only the dryer is OEM...

The good news is you got the dryer drilled & measured. The fact that it had that much oil when it locked up says it was not grinding itself to death, so the evaporators should be clear of small debris.

Was the replacement condenser you received the piccolo type?
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slawson2000
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Re: Ford C350 Dual Air - trouble

Postby slawson2000 » Mon Mar 11, 2019 1:41 pm

Lets see... The old one I took out looks to be a hybrid of sorts (maybe). It has two headers on one side. The flow comes in one header, across and back the small tubes, and then out the other header. Here is a pic of the other side of the old condenser.

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The new condenser looks to be a multi-flow. Header on each side and flat tube across them. More like a radiator. Not sure you can make out details here:

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Biggest problem is trying to get the hose to fit, or if it is even correct. When I say it is shorter... I mean it. Ideas?

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Re: Ford C350 Dual Air - trouble

Postby bohica2xo » Mon Mar 11, 2019 9:58 pm

Nice. A true parallel flow unit as a replacement. The best heat exchanger available for MVAC at this point in time. If you look closely at the headers you will see the dividers. The refrigerant makes passes from one side to the other through some of the tubes, and back across through others.

Your refrigerant charge weight will actually go down a little with that unit. Less interior volume, yet more surface area. More efficient.

Did you get that hose through AMA? If so call Tim & he can help you figure out the right one - and swap it out. Same goes for the compressor. Sometimes with 3rd parties involved in a vehicle build like the Centurion, the "book" part is not the right one. A good vendor will work with you to get it right.

Your original unit was sort of a half-step toward a piccolo - Ford saw the problem with 134a early. I have not see that condenser in a very long time. I think it was a short term thing.

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