AC check over before recharge

[Mich1958]

Hi Guy's

Just looking for a few pointers before I try and recommision my AC.

So 1st thing I have no idea how long the system has not been working for, so I had a word with my pet AC guy and he has advised me to do as thorough a visual an inspection as i can manage making sure all the stuff looks like its there, tight, dry and not obviously broken.

Whilst doing so I found this   I,m guessing that the low pressure switch has been bypassed because A the pressure was low or B the switch is stuffed or C something else.

So my guy has advised me to replace the low pressure switch and the dryer accumulater then take it to him and he's going to fill it with nitrogen for a pressure test.

Is there anything else that I may be missing before I change out these parts that may be a Delorean quirk.

Thanks guys

Cheers Mich

[Rissy]

That looks like a later accumulator (good). That looks likes like an original HP switch assembly (ok).

Was the system previously charged with R12, R12 replacement, or R134a?
Do you have original hoses, or new replacement hoses?
Is it still the original compressor?

These are fairly important questions.

I’m guessing you’re wanting it charged with R134a. If it’s previously been R134a, then fine/ok if original kit (if it was fully cleaned of all non compatible oil), great if you’ve got new replacement kit. Bear in mind that original kit won’t hold R134a for a prolonged period of time because the original kit is designed for R12, which has bigger molecules compared to R134a which means R134a will continually be leaking from an R12 system. It may only last 2-3yrs if you’re lucky.

Not just myself, but others here will recommend to replace EVERYTHING with new kit, and build yourself up a R134a system. Do it once, do it properly. However, this is normally advised if you know you’re sporting all original kit. You don’t it seems.

The best way to assess condition, is to go round breaking all joints with a mind to replace all seals for new, lubricating them with PAG100 oil as you go. You’ll also want to replace the orifice tube. Accumulator (as your guy has said). You may find in doing this process that it’s obvious that the inside condition of your system has clearly seen better days, and you’ll know what you feel is right to do at that point. My system was completely shot. I replaced everything. I did it once, and properly. Granted it’s expensive to do.

As for your electrics. Ideally, what you should be aiming for, is to put it all as it should be. No bypasses (or whatever is there) because it’s designed as it is for safety for the system and for yourself. That looks like a botch right there. Undo and correct/fix to remove the botch. A bypassed LP switch means your compressor is at risk of being burnt out.

I hope that helps.

[Mich1958]

Hi Chris

Thanks for the prompt reply and the advice I will update my AC guy.

So it appears that the compressor and conecting pipework are original as to the rest of the system it's a bit of an unknown.

He want's me to order the parts ie dryer and switch then pressure test it first before anything is changed.

Got my parts in the basket at D go ready and fingers crossed that it has been previously changed to R134.


Cheers Mich

[Rissy]

It’s important for your guy to fully extract everything and anything remaining of the old R12 compatible oil if it’s not been used as an R134a system yet, as mixing incompatible oils/gasses results in them becoming really quite acidic and they’ll eat your system alive from the inside out. But remember, even if you’ve fully flushed and cleared out the entire system, you’re still dealing with a compressor, and hoses, not sealed and designed for R134a, so it’ll be a charge, use, deplete, recharge again in a couple of years scenario until you replace these older parts for newer R134a designed components.

[Chris Williams]

All wise words from t'other Chris. I did convert mine from R12 to R134 using the original compressor, lines, new dryer and as it was damaged condenser. I did drain as much oil as was possible and changing what was in the compressor. And it worked perfectly...... but only for about 18 months as the gas did indeed slowly leak (probably) as suggested through the original lines. I have since fully converted it to R134 and although ironing out some teething issues it works much better now.
Ohh and be warned less than 50% of the new low pressure switches work correctly if at all !!!!
Chris