looks like my Chinese aircon pump has stopped functioning after a couple of months but it could be 2 faults appearing at the same time.

 

Had a sqwalking noise from then auxiliary belt area, I thought it was the alternator pulley over-run clutch, sounded just like it and I could get it to start and stop by increasing the electrical load with the lights and heated rear screen.

 

Was confident that had failed till I noticed the aircon was not cooling, it could be 2 faults and the aircon could have resulted from me disconnecting the battery to do parasitic drain tests, I dont know that it has worked since.

 

So did VDCS tests on the aircon, good pressure at 4.7 bar, no compressor shut down codes = 00 = good to go, what is displayed as "turbine voltage" I believe to be the modulated voltage going to the compressor control valve and here I saw an anomoly, normally it displays I think the term is "commanded voltage" and "measured voltage" and before when it has been working they have been the same, now there is no measured voltage, I could be mistaken and perhaps there was never anything in that field perhaps someone can confirm.

 

Anyway when I drop the temperature setting the commanded voltage rises from zero to 3 volts and then up to 9volts as before but the pressure does not rise, the condensor temp does not drop and the air from the vents remains at ambient, this is pretty much how my old failed compressor behaved so maybe I imagined there was something in the measured voltage field.

 

I did try plugging in the old cleaned and tested control valve to the loom and its not being activated, now I have finished the days work I will go and measure if there is a voltage to the control valve, if there isnt does anyone know what fuse would feed it?

 

Just when I was feeling smug about having cold air this summer

 

PS, I am losing my English, how do you spell squalk, sqwalk, squwalk as in the noise a parrot makes? none of them look right to me now.

Edited 9 June, 20197 yr by J.R.

Fuse 4 or 16, I think.

Thanks, very timely, on my way out with the multimeter and 2 panel pins now!

Squawk by the way (had to look it up though ).

Looks like the compressor has lunched itself measured 12v on the control valve connector and it threw up a fault code when unplugged, plugged in the old one and whilst I could not see or feel it move (its probably foutu as well) it got hot so the controller is trying to activate the compressor and I think the turbine measured voltage is a red herring, it has never been displayed.

 

No more squawking but a graunchy rattle at certain revs if you modulate the throttle.

 

I think its a case of buy cheap buy twice, dont suppose I will have much joy from a Chinese seller, probably too late for Paypal, I bought it in February, I might have some leverage because like many of these listings it claimed the article was in the UK unless Southampton is a suburb of Zienjing!

 

A shame because it looked very well made as do the rear brake calipers that I fitted this week from the same manufacturer (Maxspeedingrods)

Edited 9 June, 20197 yr by J.R.

When you replaced the original was the system flushed before the new compressor was connected up? Was there the correct amount of oil in the pump, was it drained/weighed and replaced?

No because I would have had to replace the whole radiator/drier assembly, I took a punt as the old pump when stripped was spotless and sterile inside and the fluid that drained out clean.

 

The new pump had some oil in it and was sealed, how much I do not know, I am very sceptical about the regas as it was done by a friend in his workshop and both he and the other guy did not really know what they were doing, there was supposed to be oil in the regrigerant but whether there was or was it enough I do not know, only that 525 grammes were put in.

 

The next one will be regassed by Norauto, they may not know a lot more but their machines are pretty idiot proof.

 

It had been evacuated before I connected up the last compressor if that counts as flushing. Do you have any recommendations for this one? If there is any sign of debris I will have to bite the bullet and replace the rad/drier.

Flushing is usually done using nitrogen and is required to remove any crap and moisture in the system. Weather there is any debris in the system depends on a lot of factors. If for example exposed to ambient air due to a (huge) leak, there is a higher risk of it.

 

An AC system can usually fail on multiple ways

- Leak (on the O2 its common on the nut of the drier due to corrosion or the condensor (stones and other debris - thats why many people add an additional guard)

- Failed AC pump (usually caused by insufficient refrigerant.

 

Refrigerant is in the system mixed with the oil, which should keep it lubricated. On some cars, without lubrication, the compressor eventually fails, and just locks (causing the belt to snap). On the O2 there is a CVC compressor used, which runs always, but has an internal pulley which will break in such case (instead of damaging the belt which also drives eg the alternator)

 

If the compressor still runs, but there is no refrigerant, lubrication is limited to none. Oil will eventually overheat and become dirty - causing the compressor to fail. In those cases it's highly recommended to do a flush, not only for removing the moisture but also the old oil. Without this done, the expansion valve will sometimes fail over time.

 

Most new compressors do have some oil, but thats just some amount, not car model specific. When replacing the compressor, its always mandatory to add sufficient oil (/verify the amount in the compressor) before starting it.

 

Also note that the oil required in the O2 is hygroscopig, thus attracts moisture. If the AC system is open for a longer time, I would purge it with nitrogen and vacuum it for at least 2 times (double evacuation). HVAC specialists generally recommend triple evacation, but since a car system is smaller than a home system I personally think a double will do just as fine.

 

 

Machines at a mechanic are indeed fool proof, but they only do measure the amount of removed refrigerant/oil so they can reapply these amounts. They don't take other factors into account (eg already removed, oil left in the compressor, and so on)

I wouldn't trust such a machine, but go for someone who actually has knowledge and equipment to do a regas manually (thus reading the measurements, and calculating sub/superheating),. Pressing some buttons doesn't require knowledge, but doing further diagnoses does. Hence I won't go for a local mechanic, but for a AC specialist (Which, generally, is not a local garage who happens to have an AC refill machine)

 

 

(Hope this is clear, might have some mistakes it, since English isn't my native language)

 

Edited 10 June, 20197 yr by DJSmiley

I've seen many a new compressor installed only to fail again very soon due to poor installation.

 

One thing you have to be aware of is genuine compressors are pre-filled with 100% of the oil volume required for the system. This makes sense on initial assembly as the rest of the system will be 100% empty. However even after recovery of a system that has been run there will be oil distributed around the system. So by adding 100% of the oil capacity to the oil that's in the system then puts the total oil too high and they compressor locks up.

Thanks for the replys and DJSmiley your English is perfect like all my Dutch customers!

 

Mine has never been run without refrigerant, open to the atmosphere or run dry with the new pump in place (I used a shorter belt) I was told that the refrigerant (added after it was vacuumed which would have presumably removed most of the old oil) contained the necessary proportion of oil, I'm not too sure but the chief meccano at Norauto knows his stuff and I trust him to refill the next pump properly.

 

Chinese seller doing the usual "dont worry sir, we will do everything to solve your problem, please send us loads of photos to show your problem............." 😕 I thought perhaps one of an ice cream cone melting!

Good call from both of you!

 

Removed the belt and turned the pump by hand, moves freely for a couple of revolutions then tightens up and squeaks and at that point it feels dry, hard to describe but I would be fairly sure.

 

I dont think they added any oil, they didnt really know what they were doing, I watched them pull a vacuum then refill with the correct weight of refrigerant, when I queried the oil they just showed me a dusty bottle on the shelf beside the machine and said that it was within the refrigerant.

 

From what you are saying I surmise that first a given volume/weight of oil should be introduced and then the refrigerant, I will find the info first (any idea where to look?) and then keep a close watch over the proceedings next time.

 

What pees me off is that I do all that I can to be autonomous and to avoid all contact with the motor trade because it usually ends like this but practically you cant buy and maintain every bit of kit.

 

Every car I buy I spend the first 6 months finding and fixing all the bodges that the motor trade have committed on it and in the process find the real reason that the seller wanted rid of what looked to be such a good vehicle and with some determination does become one.

 

It just sucks to have to buy a new part twice but Joe Public would probably be screwed for labour charges both times.

Found it, 100-120 millilitres.

 

Do you think that I should drain the new pump before fitting?

 

It wont be driven before filling, the short belt for the alternator only will be fitted.

 

I guess if I drain it I could measure the quantity.

Edited 10 June, 20197 yr by J.R.

If you drain the compressor, there is still oil left in the refrigerant hoses, condensor, evaporator and a small amount in the compressor itself.

 

I wouldn't go beyond 100ml. For a new system (new condensor, new evaporator, new hoses) 120ml would be fine, but in an existing system.. 10-20ml is (just a guess) not unlikely to remain even after draining. You're never able to empty 100%.

 

When I did replace my condensor, I've added about 15ml. Just a random 'guess' since I'm not an AC guy, but now, 2 year later, AC still runs...  I just assumed this amount was left in the condensor which failed and I had replaced.  System was empty, and I've added 525g refrigerant. It was a DIY job, just measured the full bottle, and inserted refrigerant in the system till the bottle lost 525 grams in weight  (using a kitchen scale) 

 

(Bought a vacuum pump on Amazon for about 50 GBP and a 900gram bottle refrigerant for 38 euro). And I had luck, despite not having the proper certification they did send the refrigerant

Refrigerant prices have gone up pretty much, I should have invested in refrigrant instead of bitcoins

 

Edited 10 June, 20197 yr by DJSmiley

Essential thatthe tight PAG oil for the type of compressor is used. 

 

Oil is introduced into the system whilst the vacuum is being held (same as the gas). 

 

Flushing removes all the old oil

I can be fairly sure now that the compressor failure was down to lack of lubrication, removing the drive belt and replacing with a shorter one to drive only the alternator has resulted in an immediate decrease in fuel consumption of at least 5mpg almost certainly more than that over 2 different journeys that I regularly make and know the consumption figures of obsessively.

 

Muppet mechanic mate just pulled a vacuum and refilled with 525 grammes of refrigerant gas.

 

Can anyone explain the correct procedure so I will know my stuff when I talk to Norauto and can see if they know theirs?

 

I presume when the vacuum is pulled any oil in the compressor will be evacuated, is it seperated and measured? do they first let back a measured volume of oil before the weight of regrigerant charge?

The vacuum cycle doesn't normally remove much (if any oil), the oil is too heavy and remains in the system. The only way to remove all the old oil is to flush with the appropriate kit and adaptors.

 

For a regular component replacement you would -

 

Recover the system

Replace the component

Vacuum for 30 mins (more if you can) and allow to hold to check for loss

Recharge system injecting oil and tracer dye (if applicable)

Test - if the compressor has been replaced follow the guidelines on the first running in procedure.

 

For compressor internal failure

 

Recover the system

Remove the compressor

Connect the flushing kit

Run flush as per guidelines

Install new compressor

Replace drier

Replace TX valve if required, minimum remove and inspect

Vacuum and hold

Fill system. If genuine compressor used add no additional oil. If aftermarket compressor used add the recommended total oil for the system. Add tracer dye if required.

Test - carry out compressor run in procedure

When I get the new pump (I am going to buy one, its not the suppliers fault) I will drain out the oil, measure it and refill it with the correct oil just in case what they have used was substandard, that way I will know how much was in the last one I fitted.

 

I am also going to bite the bullet and buy a vacuum pump, I already have the guage set so now I will only have myself to blame if it doesnt work.

 

Can you still buy the canisters of R134A?

 

Will have a search in a minute but if anyone can recommend a supplier or steer me away from a mistake it will be appreciated.

 

I am going to turn this misfortune into a learning experience and an opportunity to buy more tools and to be more autonomous.

Filling an A/C system is not something you can really have a go at yourself, measuring the gas is critical.

 

Plus technically you have to be licensed to handle the gas anyhow.

15 hours ago, J.R. said:

When I get the new pump (I am going to buy one, its not the suppliers fault) I will drain out the oil, measure it and refill it with the correct oil just in case what they have used was substandard, that way I will know how much was in the last one I fitted.

 

I am also going to bite the bullet and buy a vacuum pump, I already have the guage set so now I will only have myself to blame if it doesnt work.

 

Can you still buy the canisters of R134A?

 

Will have a search in a minute but if anyone can recommend a supplier or steer me away from a mistake it will be appreciated.

 

I am going to turn this misfortune into a learning experience and an opportunity to buy more tools and to be more autonomous.

 

With the proper tools you can. But you do need a proper set of gauges, hoses, connectors and so on. And the knowledge to calculate the required pressures (which depend on ambient temperature/humidity). 

 

As for the refrigerant: You need to have F-gas certification in order to buy and/or work with refrigerants. Having this certification proves you have the knowledge to work safely (both for people and environment) with these gasses. 

So without this, you shouldn't be able to buy refigerant (In theory).

 

In reality: If you 'know some people' you still can get it (hell, I can even get some R22 if I need to). While ordering online: Some vendors don't pay really close attention about having the certifications and just deliver it to your door (Like mine)..

 

But as stated by Tech1e: Its not only just adding refrigerant, having at least the knowledge how AC systems work will be the minimal to even consider it DIY. And as he says, you've to ignore any laws regarding licensing (which you probably don't have).

 

 

But like a lot of things: Sometimes its better to leave it to a professional, unless you're really sure what you're doing and know the risks.

(The same for example applies to change a switchboard in your house while you're unable to disconnect the utility lines. Can be done, but doesn't mean this is recommended as your first DIY job)

 

Edited 13 June, 20197 yr by DJSmiley

I wired this whole building, 7 apartments, the colonne collectif (3 phase distribution to each individual electricity supply) all signed off by EDF and Consuel.

 

When I stop learning I start growing old, most of my learning is by my own mistakes and overconfidence, thinking I know what I am doing when in fact I needed to study, like putting oil in the new compressor before getting the system recharged, its not the fault of my muppet mechanic friend (he is a muppet though!) but mine through not knowing.

 

Its the problem getting gas thats putting me off spending a bit more for a vacuum pump, I can get it from China in the smaller canisters but what is really inside, the cost of them and the pump is more than a recharge at Norauto.

 

I will buy and fit a 2nd new pump, drain and refill it with the correct oil (then I will be 100% sure uts done) and then probably get Norauto to do a recharge.

This is becoming a major and costly "on a mission"

 

I am now doubting my sanity buying cheap chinese aircon pumps, its not a case of buy cheap buy twice but maybe three times now.

 

First replacement Chinese pump worked for a couple of months then was holding pressure but not cooling and making graunching noise, used a shorter belt to bypass it and could feel the graunching when turned by hand.

 

2nd new pump bought, first new one removed, 2nd new one fitted awaiting re-charge then found the problem with the first was in fact the splines had stripped in the bore of the aluminium pulley, I had the bits of the original pump so was able to recondition it, the inside felt fine, had I known I could have repaired it on the car, kept the gas in the system and not bought another shonky pump.

 

NorAuto advises that the 2nd new pump was leaking they could not charge the system, I was sceptical thinking that they just did not want to do a complete refill of 525g rather than a top up so I bought a vacuum pump to go with my manifold guages, then found I have to buy expensive oil for the pump as well.

 

Tested it today and could not pull a vacuum and what was there dissapeared in an instant, definitely a leak. NorAuto said it was leaking everywhere, inside and out but I'm convinced that was just the usual bull**** when faced with the unfamiliar situation of someone actually asking them to be precise which they could not.

 

It could be one of the O rings as I did not replace them, never have done in the past and always got away with it but maybe not this time.

 

I did notice that while pulling a vacuum on the low side with the high side shut off the vacuum was being pulled there as well, my question is should the low and the high side be completely isolated and airtight from each other? I hope not because if they should then there is indeed an internal leak and not just an O ring to change.

 

I might be putting the first Chinese pump back on with the pulley from my original one.

 

Its been an expensive learning curve but at least I have got some diagnostic tools and knowledge out of the experience, its a shame the first new pump failed just before the canicule.

Edited 19 July, 20196 yr by J.R.

6 minutes ago, J.R. said:

NorAuto advises that the 2nd new pump was leaking they could not charge the system, I was sceptical thinking that they just did not want to do a complete refill of 525g rather than a top up

I'm going to guess that you didn't know that the standard method of recharging an AC is to drain the old refrigerant, and then refill with new?

1 minute ago, KenONeill said:

I'm going to guess that you didn't know that the standard method of recharging an AC is to drain the old refrigerant, and then refill with new?

 

Just what I was about to say. In order to fill the system there needs to be a vacuum so it’s Recover, Vacuum, Charge. 

Of course I did, but I had vented it to fit the second new pump so there was no gas to evacuate (a better word than drain)

 

After all the work and studying I have been doing over the last 6 months, the replacement of various parts, testing with the manometres and VCDS plus watching a few evacuations, pressure tests with nitrogen and regasses it would be a pretty poor show if I didnt know how a system is re-charged.

 

Now does anybody know if the high and the low side have an isolating valve or whatever between them?

59 minutes ago, J.R. said:

I was sceptical thinking that they just did not want to do a complete refill of 525g

 

I was referring to that statement, you have to do a complete fill.