Automotive Air Conditioning Information Forum (Archives)

woodbine on Thu July 03, 2014 5:46 PM

Year: 2004
Make: Fiat
Model: Scudo
Engine Size: 2000cc
Refrigerant Type: R134
Pressure Low: 0
Pressure High: 0
Country of Origin: Italy

Hello to all.

I have lurked on this forum, but just joined and this is my first post.

The a/c hasn't been turned on for 6 years due to a broken switch. The switch has now been fixed, but the system pressure is zero and the compressor doesn't start, but isn't seized.

It's a 2004 Fiat Scudo van, diesel 2.0jtd. I'm wondering if the system is likely to be able to be reused without spending big money. Is it likely to be damaged and uneconomic to repair?

I'm not an a/c engineer so will be getting one to do the work - but want to be armed with info and advice about how to proceed. I thought poss. start with a 25 minute vacuum test, which I believe will help to boil off any moisture that may be in the system and tell if system will hold gas. Is this a good start?

Then if it leaks, get dye put in. And fix leak(s).

If the system is leak free, or leak(s) are fixed, would it be best to replace the receiver/drier before going any further? Also, when filling with gas at this stage, will some oil need to be added too? Anything else I've not mentioned that needs doing?

So many questions. Hopefully someone gan give advice about the best way to go with this and what's needed to be done. Or wether the system will be wrecked by now. Thanks to anyone who can advise.

mk378 on Thu July 03, 2014 9:11 PM

Zero pressure you know that it doesn't hold gas. You should start with a pressure test. If there is a big hole (for example, damaged or corroded condenser), flushing the other parts and changing the oil could be a good idea. PAG oil absorbs moisture readily and pulling a vacuum doesn't remove it, the contaminated oil should be replaced.

Edited: Thu July 03, 2014 at 9:11 PM by mk378

woodbine on Fri July 04, 2014 12:32 PM

OK, thanks for your reply mk.

When you say start with a pressure test, is that a Nitrogen test, or are there others?

Can you explain what method(s) are used for flushing the other parts? Are they flushed on the vehicle,or removed from the vehicle to do this?

Also, do you recommend that the drier/receiver is replaced. If yes, should it be replaced before or after the above work is carried out?

Thanks for your help. Much appreciated.

woodbine on Wed July 09, 2014 5:04 PM

BUMP

HECAT on Wed July 09, 2014 9:03 PM

You could pressure test with nitrogen, or pull a vacuum and test for decay. Either way you will need to determine if it is a large or small leak issue. A large leak would indicate system has been open for a long time and the oil would most probably be too contaminated to produce adequate compressor lubrication. A small leak may indicate a charge was present for a considerable amount of the 6 yrs. of inop and the oil may be in better condition to go ahead and use. If small leak, you may try to fix the leak, change the filter/dryer, vacuum, and recharge (this would be most economical). But, understand that either way is just guessing at probabilities and would be no guarantee the compressor would be properly lubricated or last. The only way to guarantee oil quality is to remove (flush) and replace with new. The compressor if reused should be oil drained and oil flushed (no solvent). That procedure is on the A/C procedure page. More details about flushing is in the PDF file in my signature. Armed with this information, the next step would be to discuss this all with your chosen A/C technician

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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 

woodbine on Thu July 10, 2014 5:21 PM

Thanks for your reply HECAT.

Can I assume that after 6 years of not being used, any/most oil will be in the compressor, especially as it is by far the lowest point in the system? So flushing the compressor will get rid of most of the system's oil?


Looking at both replies, I think my best course of action will be to -
1) Quick vacuum test to confirm a leak
2) Trace leak with nitro or dye tests.
3) Fix leak(s)
4) Flush compressor and any other parts that can be done at the same time, excluding the condenser
5) Replace drier/receiver
6) Replace oil
7) Refill refridgerant

If I have forgotten anything on this list please let me know.

Thanks again to both of you for your help.

HECAT on Thu July 10, 2014 5:42 PM

No, with a system that has lost charge, we would assume most of the oil will be in the evaporator. But this assumption would be based upon an operating system that slowly looses its charge.

I think you have put together a reasonable course of action; but please allow me to clarify...

#4a: Do not solvent flush the compressor. If reusing, oil rinse only; here is the procedure.

#4b: You will want to back-flush the condenser, unless you are replacing it.

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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 

woodbine on Fri July 11, 2014 8:13 AM

OK thanks. I just assumed the oil would make it's way to the lowest point, but obviously not.

Just two last questions before I get things under way.

1) Will an a/c engineer be able to properly flush the evaporator successfully without lots of dismantling - presumably the evaporator doesn't need to be removed for this?

2) How successful is flushing a modern condenser (van is 2004) - as I understand that the galleries in recent condensers are very narrow - or is replacement a better option?

HECAT on Fri July 11, 2014 8:52 AM

Quote
Originally posted by: woodbine


1) Will an a/c engineer be able to properly flush the evaporator successfully without lots of dismantling - presumably the evaporator doesn't need to be removed for this?



2) How successful is flushing a modern condenser (van is 2004) - as I understand that the galleries in recent condensers are very narrow - or is replacement a better option?


1) The orifice (OT or TXV) has to be removed to flush the evaporator. Sometimes this will require lots of dismantling depending on vehicle design (no two are the same).

2) If proven and capable flush tooling is not available, the condenser is often just replaced; mostly because of metal debris. Oil removal only can be less difficult.

I think it is a good thing that you are trying to understand this for yourself before you head to the repair shop. But now we are making assumptions about what your chosen professional can or cannot, will or will not do; or if he is tooled and capable for the work. It is often better to seek his action plan, and then respectfully discuss your thoughts and opinions. If he does not or cannot meet your expectations, you can choose to go elsewhere. When I worked in a professional shop, customers that dictated an action plan and did not allow me to inspect and recommend the course of action I would take (to stand behind my work), were politely sent on their way. Good Luck, I hope you have cool A/C soon.

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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 

woodbine on Fri July 11, 2014 11:43 AM

Thanks. I hear what you're saying. I work in the plumbing industry, and agree that customers can sometimes have set ideas about how things should be done that are just as often wrong as they are right.

I wouldn't go into someone's workshop and tell them how to do their job. However, now I am armed with good advice from yourself and mk, I know that if the engineer's suggestions and advice are a long way from what is written above, then alarm bells should be ringing.


I'll post to let you know how I got on.

Ian

HECAT on Fri July 11, 2014 12:57 PM

Ian,

Thanks for not taking my advice the wrong way. As a professional in another trade, I see you do understand. I was concerned you were going to march in with your action plan and not get very far. Please do update with how it goes.

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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