Back story- I got my 2001 dhse around 3 yrs ago, basket case really but I like a project! Renewed and serviced everything and coughed up for a nano, in it for the long haul! Anyway, ac didn't work and I knew nothing about ac so I booked it in for a regas at kwikfit around a year after she was put back on the road, vac test passed, regassed and lovely cold air but failed after approx 3 months. Left it around a year then booked her in at a local landrover indy, they found a leak in the condensor using dye and a uv torch. I renewed the condenser and the compressor to condenser hose and took it back to the indy, they confirmed no more leaks and regassed the system. Lovely cold air again but failed again after around 9 months. Left it another year until today when I booked it in at a local garage who, according to their website they can find any leak using nitrogen and a sniffer probe, Google EAC in telford, shropshire to see what I'm on about. They have said they found no leak for the 20 min test. Although my knowledge of AC is minimal the bloke in reception suggested a full ac service and dye added to the system to find the leak! I was a bit pissed at that comment so paid the bill, £70, and left. They did suggest also a longer pressure test for 35 mins and a full diagnosis, I also questioned that and got a load of flim flam, I knew more than him and couldn't speak to the tech who did the sniff test as he had "gone home".
They were my last chance really and I've lost any faith I might have had in garages. In all my life I've only gone to garages for tyres and even that's gone wrong twice, and tracking which cost me 2 ruined tyres in 4k miles.
So where do I go from here?
I'm handy, not too stupid (except car electrics but I'm getting better!) Can I DIY leak find on an empty system?
Tia
Chris.

Clean the whole engine bay and then have a look for UV traces after running at pressure... I've had various leaks across a few LRs, condenser and hoses were the easy ones, but I also had a leak from a compressor, at the clutch
...Unless you find the UV trace then dont waste time, and just recharge in May each year?
I assume the clutch is pulling in as it should? If not then there are other fixes to consider

romanrob wrote:

Clean the whole engine bay and then have a look for UV traces after running at pressure... I've had various leaks across a few LRs, condenser and hoses were the easy ones, but I also had a leak from a compressor, at the clutch
...Unless you find the UV trace then dont waste time, and just recharge in May each year?
I assume the clutch is pulling in as it should? If not then there are other fixes to consider

I've got a uv torch and had a look a few weeks back but there was green everywhere, even fingerprints, either from the last leak test and regass from the tech or from me working on the condensor/hose replacement. System works great, with gas in it, its 100% a leak somewhere which they, according to their website, would find.
If I get it regassed, with dye too, is it possible to differentiate new leaks from the old staining? Am I expecting to see a mist?.

Or a way to use compressed air to find leaks? Got a compressor to get to 10bar. Guess I'll need special fittings for the ports.

The only way you can find a leak on an empty system is by putting pressure in it and checking. If they are doing the leak test properly they won't use pure Nitrogen but what is known as trace gas which is a mix of Nitrogen and another inert gas that can be detected with an electronic sniffer. The Kwik Fit and similar use a programmable machine and in most cases have no idea what it is they are actually doing. They connect the machine, tell it what car it is so it can use a look up table to identify how much gas it needs and press the go button. Doing it manually you recover any remaining gas, fill the system with Oxygen Free Nitrogen (that's what it says on the cylinder anyway but if it had any Oxygen in it, it would be air surely?) at 10 bar and leave it for 30 minutes or, if using a digital gauge any leak will be seen in 10 minutes, and see if the pressure drops. If it doesn't then you let the OFN out, vacuum out the system (down to less than 0.01 psi) and fill with the correct quantity of R134A refrigerant.

The difference is the machine only pressurises to 3 bar which is below the operating pressure so it may not show a leak whereas if done properly it will. I install domestic AC systems and on those they are pressure tested to 40 bar and ideally left for a minimum of 2 hours. So although I don't have any R134A, I do have the kit for pressure testing. The other halves Merc was losing gas after 3 or 4 months so I pressure tested it at 10 bar and it had to be left overnight before the pressure drop was noticeable. It's a shame you aren't a bit closer to me, I have two friends (both former P38 owners as it happens) that are mobile AC engineers. On a very small leak like you have there's three options. Replace anything that hasn't already been replaced, get it gassed by Kwik Fit (or ATS who often have cheap deals through Groupon) every year or use a leak sealer. The latter will keep it running for a couple of years at least on a small leak (the missus's Merc has been working for almost 3 since we put some in) and Halfords do a small can for around £20. The problem there is that it needs to be added during the regas process. The system is half filled, the can attached and some of the gas is allowed into the can, shake it about a bit to mix the two liquids, then let the mix into the system before continuing with putting the gas in. So not an option if someone is using the programmable machine as they won't be able to interrupt the process.

I know my compressed air will allow some moisture in(bad) but only for a day or so until I can get her booked in for a vac/regass (good? No real harm done?). I'm sure I read somewhere ages ago about someone using compressed air at home to find a leak but can't find it now. I recall the fittings needed caused some head scratching but was solved somehow. I've got pipe fittings, bsp, here and pressure gauges, hoses, pushfits, ballvalves etc so I could probably knock up the bulk of it just the port fittings to solve.
If I do get it regassed along with dye..what's the best method or stuff to use to get the old green staining off, it's everywhere. If I could pressurise the system at home I might be able to hear a hiss at 10bar but I could be talking ball clocks haha 😄

You'll need a pair of these,https://www.amazon.co.uk/Connector-Extractor-Condition-Adjustable-Coupler/dp/B083M2CV1P/ref=sr_1_21_sspa. The standard connection on all AC hoses is a 1/4" flare so you'd need the correct hoses too, although for the price you could even splash out and get yourself a kit like this https://www.amazon.co.uk/KATSU-Tools-Manifold-Conditioner-Refill/dp/B094R8NCVZ/ref=sr_1_5 so you will have the connectors and hoses.

The recommendation is not to use air to pressure test as it will introduce moisture which means you should really replace the dryer. However, there's thousands of cars that have been running around with no refrigerant in them for years before someone decides to sort things out and the while system will have been full of air all that time and a simple regas will do the job.

Chris, to clean the engine bay i just used regular solvents - meths or worst case, acetone (i wouldn't use that on the hoses though) . That said, your engine bay sounds greener than mine ever was :)

Another problem I have found with using a UV light is anti-freeze also glows green. So if you've ever had a coolant leak or spilt any, you'll see green everywhere.

I have owned my P38 for 13 years & every year or two the A/C needs to be regassed but then works well for a year or two. This year I was going to add some of the A/C leak sealant while having Richard's mobile A/C chum regass it but as he was on holiday I got the regass done at Kwik-Fit so will need to wait until next year to use the sealant now.

For getting a system regassed taking the car to Kwik-Fit or ATS (regass currently only £45 with Groupon offer) is the cheapest option but if there is anything beyond that then you are much better off taking the car to an independent auto A/C engineer. You should be able to use Google to find a local ndependent auto A/C engineer.

Gilbertd wrote:

You'll need a pair of these,https://www.amazon.co.uk/Connector-Extractor-Condition-Adjustable-Coupler/dp/B083M2CV1P/ref=sr_1_21_sspa. The standard connection on all AC hoses is a 1/4" flare so you'd need the correct hoses too, although for the price you could even splash out and get yourself a kit like this https://www.amazon.co.uk/KATSU-Tools-Manifold-Conditioner-Refill/dp/B094R8NCVZ/ref=sr_1_5 so you will have the connectors and hoses.

The recommendation is not to use air to pressure test as it will introduce moisture which means you should really replace the dryer. However, there's thousands of cars that have been running around with no refrigerant in them for years before someone decides to sort things out and the while system will have been full of air all that time and a simple regas will do the job.

£50, that's not too scary really. I've ordered them. My system was empty for around 5 yrs before I got the car anyway. I was discussing the use of necessary 'trades' that we've had to use over the last 35 years and 3/4 of them have done a bad job or ripped me off as I later discovered. I'm self taught in most DIY things now around the home and competent at most things except AC!
A few examples..
When I was 19 I picked up a rear tyre puncture on my rd400 yamaha, nail into the inner tube, removed the wheel on the side of the road and walked 3 miles with it to the nearest tyre place. They patched the tube while I waited , pumped it up and I walked back to the bike and refitted it. Set off home and only made it a few hundred yards and it was flat again. Got recovered back home by my dad who had finished work by then and we picked up some tyre irons and removed the wheel again and the tyre to find a hole perfectly in the middle of the inner tube patch repair., and the original nail still in the tyre poking through inside.
I'm now 25 got my first house and a leak was evident on the roof near the gutter, rang a roofer from the local paper who came whilst I was at work to do the job after looking and quoting the day before. Said 3 tiles were cracked (concrete) and would need replacing and the under felt had rotted. A couple of years later the roof leaked again, same place so I decided to have a look myself, found the broken tiles had been siliconed together and a couple of plastic tesco carrier bags had been used to patch the felt.
I'm now 29 (not now now, I'm 61 but was 29 then) sold that house to buy the one I'm in now. Decided to have a swanky alarm system fitted after being accosted at the exit of B&Q by a canvasser. This actually made TV news and the guy was jailed over it, long story short, he fitted a timer in the alarm control box that knocked the system out when the warranty expired, so you had to pay for a repair, I and other victims didnt know this of course,but the nice guy did apologise for the malfunction of the system and after fitting a new battery and some other bits gave me a hefty bill but as a gesture of goodwill also gave me another 12 months warranty on the whole system free of charge as "these units never go wrong and I've just been unlucky"
15 months later and the system goes down again, getting suspicious I rang a different alarm company who found this relay and removed it and suggested I rang trading standards. I did so and they had already built a case up against him after numerous complaints.
The rangey needed 4 new tyres when I got it, shame really as they were all perilli scorpions with loads of tread but perished after standing for 5 yrs. National tyres had an offer on 4 new tyres with free mobile fitting so for convenience I had that done then drove the 2 or 3 miles to their local branch to have the tracking done as I had replaced every steering component with new during the recommisioning. Then straight to the mot place where she sailed through. The next bit is really my fault, but 4k miles after the new tyres and tracking were done I had my head under the front looking for an oil leak and noticed no tread at all on the inner quarter width on both fronts, the bit you can't easily see with the wheels straight ahead, but that's how it's always parked. Went somewhere else who said it was miles out and did it properly, been fine since. She seemed to steer fine with the tracking out but as it was my first 38 and my other car is an old defender I never thought anything was wrong.
Since my early years I've moved on a lot and built a two storey extention from digging the footings, casting the reinforced raft right up to the chimney pot and all internal work, everything except the plaster skim, just can't get the knack of that. Fitted new bathroom and kitchen, knocked down internal walls, built staircases, dry lined the cellar, made iron railings, laid a block paving drive, fitted a log burner, built my 110 on a galv chassis, restored a few Japanese motorbikes and hospitalised my self twice and set myself on fire once.

nigelbb wrote:

I have owned my P38 for 13 years & every year or two the A/C needs to be regassed but then works well for a year or two. This year I was going to add some of the A/C leak sealant while having Richard's mobile A/C chum regass it but as he was on holiday I got the regass done at Kwik-Fit so will need to wait until next year to use the sealant now.

For getting a system regassed taking the car to Kwik-Fit or ATS (regass currently only £45 with Groupon offer) is the cheapest option but if there is anything beyond that then you are much better off taking the car to an independent auto A/C engineer. You should be able to use Google to find a local ndependent auto A/C engineer.

Never tried ats for anything before. 3 times I've had the 38 in for ac, the indy and the place I went to yesterday you have to leave the car with them and wait for a phone call to collect. I've no real idea of what they have done because I'm not there and I doubt they would let me stand in the workshop looking anyway. Kwikfit, however, when it had its first ever regass under my ownership, had the machine right by the roller shutter door so the bonnet was just poking in and I did have a little chat with the guy but just about the ac button' light off ac on thing' incase he didn't know. Then I wondered off and sat on a nice picnic table they had under a shady tree. Kwikfit have a time slot so I CAN be there and maybe be sure the correct amount of gas is put in without maybe going into the workshop and upsetting the H&S peeps if the ac machine is in the same place as before.

Forgot to add to my moan about bad service above. The place I went to yesterday for the nitrogen sniff test had unplugged the lead from my dash cam, why would they do that!
It's hard wired in, cable runs under the windscreen piller trim and under the headliner and the cam fits nice behind the rear view mirror. USB fitting is extremely snug and only about 2" cable showing and its impossible, to me , to accidently disconnect it. They have two branches about 5 miles apart, I dropped off the car for the test at the nearest branch to me and didn't find out that they had took it to the other branch as "they don't have the gear at this branch and the nitrogen is not transportable" until I went to pick it up from the original branch they booked me in at. Didn't want me to see any thing unsavoury? 2 or 3 speed cameras depending on what route they took, hope I don't get a ticket with a poor photo!

That's a bit sneaky, if you don't get anything in the post in 28 days, they didn't get flashed...... We've all been bitten at some point, which is why I do everything myself and don't take it in to anyone. I started playing with engines when I was 11 (I'm now 68, 69 later this month) and have always tackled most things on cars and bikes. So mechanics was my hobby but work was radio communications and electronics until I retired just as lockdown started, which was a bit of bad planning but when I'd put my 3 months notice in, nobody knew what was to come. I'd intended getting a part time job (van driver for Euro Car Parts or one of the other local motor factors was high on the list) to top up the (pretty decent) pension until the State pension kicked in but lockdown killed that idea. Those that were still working were working from home, including my daughter who was using a spare bedroom as an office, and the weather got very hot. She rang me and asked if I could install air conditioning for her. Looked into it and found it was electrics and plumbing, both things I could do, but found that to even buy a unit I needed to be F-Gas registered. A mate had done a course to do car AC just before lockdown and he recommended the same place he had done his course at. I rang them and while the car AC course is one day and a fairly simple exam at the end of it, the full F-Gas for domestic and industrial was a week but, as I had nothing better to do, signed up for it. Did the course and asked what was different in my course to what my mate Danny had done. I had been taught how a system worked, all the legislation involved as well as practical tests whereas the car course just taught you how to do it and why you did it the way you did. So on the last day I did my F-Gas practical test, then the exam, had a coffee then did a regas on my car and sat the exam for the car course, so I ended up with both qualifications.

Put an AC system in for my daughter, two indoor units in the two bedrooms from a single outdoor unit and it was working perfectly. A couple of days later she was on a Skype call with her boss who noticed the AC unit on the wall behind her. Put one in for him the following week. I put a free advert of facebook and it went from there. I won't work more than 3 days a week, ideally only 1 or 2, but it keeps me busy and as each job is different it can be quite interesting at times working out the best way to run pipework, where to mount units and so on.

Another mate is a full time professional musician but as all the theatres were shut during lockdown, he had no work and was asking me about the work I was doing. I told him about the one day car AC course so he did it too. So the pair of them cover Cambridgeshire, Bedfordshire, Buckinghamshire and Hertfordshire. But, not having been taught the theory like I was, I still get phone calls when they find something they don't understand and that is people that have been taught how to do it and not someone who has simply been shown how to use the machine.

I guessing I could install a bedroom ac unit myself then being plumbing and house electrical competent? The extension I built is a new lounge downstairs and our bed room upstairs. It gets uncomfortably hot in bed , window is open always at the back, shut at the front as that faces a busy road and the new craze of pop pop bang bang car exhausts stops me sleeping, rads are off 99.9% of the time too but we are never cold in bed. AC just in that room would be nice. Got a scaffold tower, fell off that once, hammer drills, stihl saw etc so no issues fitting one if it's legal.
I've loved anything mechanical, older the better since I was a nipper, clockwork stuff I like too, got 5 long case clocks here and 3 wall clocks which I usually fix over a winter when I don't like being outside. I'm no expert but I can strip, clean, rebush bearings and set them up quite well. I've no idea how people who can't do basic stuff with their hands survive these days, trades are shockingly expensive and no one round here seems to want to even wash their own car, mow their lawn, clean their drive or cook their own food anymore, they pay someone to do it which I find bizarre when they then complain about the cost of living.
Back to the room AC, and being too hot in bed thing, we have tried sleeping on top of the covers with naff all on but that's not a pretty sight for either of us when the light goes on. Best covered up!

You probably could, most DIY competent people over the age of 50 would be able to do it, only problem is getting the units. Due to them being charged with Ozone Depleting gases it is illegal for anyone to supply to a non F-Gas registered person. Then it needs to be commissioned by a qualified person too and there's the kit you need to install and test them which cost me over a grand for the bare minimum. There's a couple of dodgy suppliers you find on the internet that will supply to anyone (they've already been prosecuted twice but just pop up with a different name) but they supply some really horrible Chinese made units that I doubt will last much more than a couple of years.

I've installed quite a few systems in living rooms but whether it is really worthwhile I've no idea. The customer wants one in the living room so that is where I put it..... My daughter has found that if she leaves the bedroom units on at 21 degrees and leaves the doors open, the cool air falls so they cool the whole house.

You are quite right though. I saw a survey that had been done recently on the practical skills of people broken down into age groups. It was things like can you hang wallpaper, can you wire a 13A plug, can you change a tap washer, can you change the wheel on your car and so on. What they found was that the vast majority in the 50+ age group answered yes to almost everything, those in the under 30 age group answered no to almost all of them. It isn't surprising there are so many cowboys about these days as there is a rapidly diminishing number of skilled (or even semi-skilled) people about as the younger generations would rather learn how to sit behind a computer rather than go out and get their hands dirty doing something practical.

I was having AC leak issues on one of mine a few year back. As the system was completely empty, no dye in it & needed a new dryer, I used compressed air to do the test. Filled it to about 8bar, and then used soapy water. Found the leak pretty quick on the condenser. Swapped that & the dryer, and whe nre-gassing asked them to do the vacuum for extra time to be sure !! Yes Gilbert, I know it's wrong !!

Worked fine for 2-3 years, and then got another leak. got it checked & regassed, but was low again after about 4-6 weeks. No signs of leaks or dye anywhere this time, but noticed the compressor getting noisy behind the clutch. Took clutch off & hey-ho there was the leak. Not enough for the dye to get all over the compressor, but enough to lose the gas.

My other P38 still has vacuum on it after 2-3 months so will be re-gassing that soon.

Pete12345 wrote:

Yes Gilbert, I know it's wrong !!

Technically it is but any system where the refrigerant has leaked out is full of air so it isn't any different. Strictly speaking the dryer should be replaced but even if it isn't, it'll still work, maybe not at optimum, but it will work.