A/C System diagnosis 2

Because wally can't see the sub headings I'll write them in. His experience is very valuable.

I recently purchased a Refrigerant Identifier ID 1234 yf. I've managed to find more information about it online than came with it. I wanted to ensure that I was going to use it correctly before I tried it, hence no trial and error testing. When I did my training and assessment for refrigerant handling back in 2015 I'd understood both from the theory and practical training that no escape of refrigerant must occur, and if refrigerant did escape to the atmosphere then you'd fail the assessment.

Okay I understood and did not have any problem. Watching the operation of the refrigerant ID 1234 yf analyser online I could see that the operators were testing systems but seemed to be disconnecting the hose from the ID 1234 yf analyser without ensuring that the hose was free of refrigerant?

I've contacted the manufacturer for advice but they have not yet returned with any information but have acknowledged my requests. I can't see a way round that using the ID 1234 yf analyser!!

A customer brought her car down from Burrow in Furness yesterday for me to mot and service it today. I was asked to look at the A/C system because a garage in Burrow had advised her that the A/C system had no refrigerant in the system!

After checking records it is twenty three months since I recovered this car from Burrow in Furness with a blown engine. Back then I rebuilt the engine and exchanged the heater matrix and cooling system radiator along with the engine oil cooler. A lot of work was carried out to the car back then. Twelve months or so later the car came back for a service and a new road wheel fitting. At that time the customer said the heater blower was failing. If I get this correct the timing of this was when COVID-19 was just starting out so she could not bring the car back for anymore repairs.

At some point she got the heater blower fixed back in Burrow in Furness. Since the heater blower had been fixed she advised me that the A/C system was not blowing cold air. The garage she said advised her that the refrigerant had depleted from the system? When I exchanged the heater matrix two years ago (approx) I bought OE Ford seals from Quicks. I had doubts the system had leaked!

Today I carried out a mot and full service before putting my attention to the A/C system. I put the Refrigerant analyser ID 1234 yf on the system (R134a) and tested it to find that the ID 1234 yf failed the test, but actually told me nothing about why the test was incomplete?

I had to assume at that point there was no refrigerant in the system. I then put the recovery machine on and went straight to manual operation to carryout a vacuum test, however, the machine advised that refrigerant was in the system!

I then did a recovery and recovered 90 grams. After this I did a manual vacuum test and left the machine to see if a leak (large or small) was present!

I then refilled the A/C system (Ford Fiesta) with 530 grams (16 mm Condenser). After refilling I operated the A/C system and it is working again as normal.

I decided to put the Refrigerant analyser ID 1234 yf back on. This time the ID 1234 yf produced some results. No contamination from other gasses and recording 100% R134a, but recorded an Air reading of 5.0%. 

I then tested my dad's car a Kia Ceed 3 2019 model diesel with refrigerant 1234 yf and recorded 100% 1234 yf and no contamination and no air.

I then tried the test again on my Kia Ceed 3 2010 model diesel using R134a and the readings recorded 100% R134a, no contamination and 5.6% air!

My A/C system is very cold once it has started to circulate and the recovery machines don't show this problem as being present.

I suspect that the air present will be because of the descant in the receiver dryer being past its useful life?

The Fiesta A/C system today is seriously cold now in operation but has the 5.0% excess air present.

Any views on this?