Topic: AC compressor (Read 4336 times)

danzigfan · « **on:** 04 July 2022, 16:13:43 »

Well...after I decided that Omega was perfect, project done....compressor gave up this afternoon...started rattling as hell, blowing warm...clutch engages and disengages normally....
I ordered new compressor and now I need to know two things:
1. How much lubricating oil should be in new compressor

2. Part number for 2 dowty washers that go between AC compressor and cooling lines

New compressor will arrive in two days, replacing it won't be a problem, but I can't find where to buy those 2 dowty washers.
Thanks in advance, Stan

Raeturbo · « **Reply #1 on:** 04 July 2022, 16:24:10 »

Take your old ones to a hydraulic pipe repair shop, they’ll probably be able to match them up👍

olm · « **Reply #2 on:** 04 July 2022, 17:23:42 »

Surely the new compressor includes them, it came to me with the gaskets

danzigfan · « **Reply #3 on:** 04 July 2022, 17:56:02 »

The last one I got, came without them

danzigfan · « **Reply #4 on:** 04 July 2022, 19:08:42 »

Does anyone know the amount of lubricating oil inside compressor?

Doctor Gollum · « **Reply #5 on:** 04 July 2022, 19:25:56 »

Should be on the AC label on the slam panel

danzigfan · « **Reply #6 on:** 04 July 2022, 19:52:49 »

It only says the amount of refridgerant

Doctor Gollum · « **Reply #7 on:** 04 July 2022, 19:59:52 »

Quote from: danzigfan on 04 July 2022, 19:52:49

It only says the amount of refridgerant

Thought there was also the PAG amount. 50ml maybe $:-\$

biggriffin · « **Reply #8 on:** 04 July 2022, 21:11:51 »

Should come with a small satchel of oil, when you go to get it reggased, the Dalek will add the correct amount of pag about 50-80ml, and 950ish of refrigerant.

Raeturbo · « **Reply #9 on:** 04 July 2022, 21:53:36 »

Yes 👍 done mine recently

danzigfan · « **Reply #10 on:** 06 July 2022, 15:01:40 »

So, just as a test, to see the amount of oil needed, I took ac compressor off my other 2.5V6, and no oil came out

...Now I'm at the starting point again.

Entire system takes 8 oz or 236 ml... If I can believe allmighty internet, condenser, evaporator and both ac lines contain app. one oz each, when you replace compressor. So the amount of oil added to it should be 236ml minus 118 ml which is already in the system.

It's slowly getting over my head...any experienced member here who did this procedure and lives today to tell?

Doctor Gollum · « **Reply #11 on:** 06 July 2022, 15:10:38 »

Quote from: danzigfan on 06 July 2022, 15:01:40

So, just as a test, to see the amount of oil needed, I took ac compressor off my other 2.5V6, and no oil came out ...Now I'm at the starting point again.

Entire system takes 8 oz or 236 ml... If I can believe allmighty internet, condenser, evaporator and both ac lines contain app. one oz each, when you replace compressor. So the amount of oil added to it should be 236ml minus 118 ml which is already in the system.

It's slowly getting over my head...any experienced member here who did this procedure and lives today to tell?

You're over thinking it

When it gets vacuumed out, the system should be empty. When it gets refilled, the new stuff will already contain the oil of an appropriate amount if done properly

Raeturbo · « **Reply #12 on:** 06 July 2022, 15:17:53 »

^what he said^👍

danzigfan · « **Reply #13 on:** 06 July 2022, 15:18:44 »

So...should I leave amount of oil inside new ac compressor as it is and just take the car with new compressor directly to regas? No worries?

Raeturbo · « **Reply #14 on:** 06 July 2022, 15:20:55 »

Yes they will evacuate the whole system before they refill it anyway

danzigfan · « **Reply #15 on:** 06 July 2022, 15:22:24 »

Thanks

danzigfan · « **Reply #16 on:** 08 July 2022, 09:48:59 »

I replaced the ac compressor, toom it to regas and more problems showed up...It holds vacuum, ac clutch works as it should, but no cold air from vents....The ac line was freezing cold at the first start, but than remain warm/hot after starting ac again. Anyone had this issue?

biggriffin · « **Reply #17 on:** 08 July 2022, 10:21:20 »

Are fans switching on when air-con is on. There's an expansion valve up behind the glove box,, very rare they fail.

danzigfan · « **Reply #18 on:** 08 July 2022, 10:23:58 »

Yes, fans are switching on

LC0112G · « **Reply #19 on:** 08 July 2022, 10:32:04 »

Can you control the internal vent temperature by changing the temperature dials with the A/C turned off? I mean, can you get both hot air and cold air? if not it could be that the flaps/actuators in the heater box are jammed.

It's also worth measuring the temperature of the two A/C pipes that go into and out of the engine bay bulkhead. One of them should be cold, and the other warm/hot.

danzigfan · « **Reply #20 on:** 08 July 2022, 10:40:03 »

A/C pipe was cold only on first start up...then luke warm and later hot. No worky $:-\$

LC0112G · « **Reply #21 on:** 08 July 2022, 11:00:10 »

Quote from: danzigfan on 08 July 2022, 10:40:03

A/C pipe was cold only on first start up...then luke warm and later hot. No worky $:-\$

This may be illegal to do yourself in your country unless you have the correct ticks in various nonsense training boxes, but....

Your symptoms sound like lack of gas to me. You need someone to put some pressure gauges on it. https://www.ebay.co.uk/itm/403116218375

These allow you to measure the gas pressures in the pipes either side of the compressor. With the engine not running, both pressures should be the same - typically 4 or 5 bar IIRC. With the engine running (well compressor running really) then before the compressor the pressure should be low-ish (2-5 bar IIRC), and the pipe will be cold. After the compressor the pressure will be high (20+ bar IIRC), and the pipe will be warm/hot.

If the system is blocked, then you'll end up with very high pressure in the HP side, and less than atmospheric in the LP side. If the system is low on gas, then the compressor can't generate enough differential across the expansion valve to give the required cooling. If the system is empty of gas, then the LP cutoff switches will stop the compressor clutch from engaging.

danzigfan · « **Reply #22 on:** 08 July 2022, 11:53:42 »

Thanks for the advice, system isn't blocked for sure, because the pressure isn't high enough, when the compressor is running. It should be around 20 yes, but it doesn't reach that pressure at all. The system took 700g of gas both times, because I went to two diferrent ac refill places

LC0112G · « **Reply #23 on:** 08 July 2022, 12:18:03 »

Quote from: danzigfan on 08 July 2022, 11:53:42

Thanks for the advice, system isn't blocked for sure, because the pressure isn't high enough, when the compressor is running. It should be around 20 yes, but it doesn't reach that pressure at all. The system took 700g of gas both times, because I went to two diferrent ac refill places

It may have taken 700g of gas when filled, but how sure are you that there still 700g in there now? Personally I don't really like filling the A/C with gas by weight/mass. Much better to do it by running pressures IMO.

Measuring BOTH the LP and HP sides should tell you what is going on. The LP side needs to stay above (about) 2 bar when the system is running, otherwise the LP cutout turns the compressor off to avoid damaging it. The HP side should reach 15-20 bar. There is a HP cutoff there too but I'm not sure what that is on an Omega - probably around 20-25 Bar.

If there isn't enough gas in the system, then you can get the LP/HP running at (say) 2Bar/10bar, which is enough to keep the cutout switches happy, but the HP side isn't high enough to give good cooling. Or if your new compressor is a load of junk similar things happen.

amba · « **Reply #24 on:** 08 July 2022, 19:38:08 »

Just had my A/C recharged a few weeks ago after last being done approx 3 years ago.

I always remember A/C system when fully vac down to hols a charge of 950 grams so I would say at 700grams your is light and whist enough to engage the compressor not enough to give correct cooling.

Raeturbo · « **Reply #25 on:** 08 July 2022, 20:46:44 »

I agree, mine took over 950. I think they actually hold 1kg (of course can vary on temp blah blah etc..,,,,

danzigfan · « **Reply #26 on:** 08 July 2022, 21:18:11 »

Did you ensist on filling the system with 900 grams?
Because they just find the car make and model on the ac machine and it says 700g on display...so the machine does all the work, no brain involved

Raeturbo · « **Reply #27 on:** 08 July 2022, 21:29:05 »

The machines normally work it out as far as I know and will fill them up.??

danzigfan · « **Reply #28 on:** 08 July 2022, 21:34:45 »

Well, I'm going to try this on my other Omega...hopefully the mechanic will be willing to fill the system with 200 grams more

Raeturbo · « **Reply #29 on:** 08 July 2022, 21:38:43 »

Just ask him to fully empty and fully fill. Although I think the automatic AC machines are programmed to fill to maximum anyway

danzigfan · « **Reply #30 on:** 08 July 2022, 23:03:57 »

Thanks

amba · « **Reply #31 on:** 09 July 2022, 15:27:04 »

The volume of A/C refrigerant should be on the white sticker on the front slam panel visible with bonnet open.

Mine shows :
Refrigerant..R134a
950grams
Compressor Lubricant PAG refer to GME specification.

So I recon if your A/C guy is telling you he has put 700 grams into the system ...he is wrong

.I would suggest you get a full refund as he appears to of not done the job correctly and possibly caused damage by sending you away with a incorrectly working system.

Take it to a proper A/C provider and question them first as to what they intend replacing entire gas/il charge with and only pay when you see the print out of pressures and air vent temperatures.

LC0112G · « **Reply #32 on:** 09 July 2022, 18:03:32 »

I wonder if it's being refiled with that new gas (R1234YF) instead of R134a?

danzigfan · « **Reply #33 on:** 09 July 2022, 18:13:19 »

No, it wasR134a...problem is it was only filled up with 700 grams...enough to engage the copressor, not enough to properly cool.

And I did some dismanteling of the dead ac compressor..the are metal parts you don't want to see in it...so to the system cleaning it goes anyway $:-\$ ...this will cost an arm and a leg all new parts included.
Talking about the new ac compressor I bought fee days ago, I installed it on my other V6 with dead ac.
I'll take her to recharge on monday, insist to fill it with 900 grams and will report on the result. It should work

LC0112G · « **Reply #34 on:** 09 July 2022, 19:00:39 »

950g

Doctor Gollum · « **Reply #35 on:** 09 July 2022, 21:24:00 »

You might find the warranty on the new compressor system is void unless the system is rebuilt $:-\$

Lines can be flushed through, but evap/condenser /drier/expansion valve technically require replacement...

amba · « **Reply #36 on:** 10 July 2022, 08:42:42 »

Few years ago my old Elite required a new compressor.Guy who has done my A/C for many years checked through and found small pieces of metal inside the old compressor unions so suspected it had contaminated the entire system.

Had all lines cleaned along with new expansion valve which was a total nightmare to replace but we ended up getting it all renewed but even at "mates rates" it was a very pricey job.....but the A/C worked again.

As nice as A/C is when things go wrong expect the costs to be significant.

danzigfan · « **Reply #37 on:** 11 July 2022, 19:49:19 »

Update:
I took old girl 2.5, which now has new ac compressor, to recharge with 950 grams of gas. Happy to report she changed into a freezer box today, ac works really nice.

Then I took 3.0 with known good compressor to recharge, and there is no better result than before.
The system took 950 grams, started compressor clutch and no cold air from vents.
It seems to have bigger issue.

Raeturbo · « **Reply #38 on:** 11 July 2022, 22:56:52 »

Can you get any air at all from your vents hot or cold?

danzigfan · « **Reply #39 on:** 11 July 2022, 23:18:47 »

Only hot/ outside temperature air

danzigfan · « **Reply #40 on:** 12 July 2022, 04:24:22 »

High pressure hose stays warm even when ac compressor is running, condenser and dryer were replaced two years ago, I've read here there are cases of expansion valve fail but I can't seem to find any "how to" anywhere. It's a shame, because it's a major dashboard out job. Even on LHD Omegas

LC0112G · « **Reply #41 on:** 12 July 2022, 10:01:28 »

Quote from: danzigfan on 12 July 2022, 04:24:22

High pressure hose stays warm even when ac compressor is running, condenser and dryer were replaced two years ago, I've read here there are cases of expansion valve fail but I can't seem to find any "how to" anywhere. It's a shame, because it's a major dashboard out job. Even on LHD Omegas

The high pressure hose will be warm. The compressor compresses the refridgerant and that gets it hot. It then passes through the condenser (radiator) where heat is lost to the atmosphere, but if the atmosphere is at 20-30C then the refridgerant will never cool to less than that, so the temperature after the condenser will still be warm/hot. The refridgerant then goes to the expansion valve, where its squirted through a small hole. This causes the refridgerant to expand, reduce pressure and get cold (like 0C) all at the same time. The now cold refridgerant then passes through the evaporator inside the heater matrix where external air is blown over it. This causes the air to get colder and the refridgerant to get warmer, but again, the refridgerant will always be below the air temperature. Therefore the Low pressure side will often be in the 5-10 Deg C range.

High Pressure = Warm
Low Pressure = Cold.

biggriffin · « **Reply #42 on:** 13 July 2022, 21:32:41 »

Quote from: danzigfan on 12 July 2022, 04:24:22

High pressure hose stays warm even when ac compressor is running, condenser and dryer were replaced two years ago, I've read here there are cases of expansion valve fail but I can't seem to find any "how to" anywhere. It's a shame, because it's a major dashboard out job. Even on LHD Omegas

The expansion valve can be removed on rhd by removing heater fan glove box,airbag, and lots of swearing,

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Author Topic: AC compressor (Read 4336 times)