How to leak test P80 AC system?

[scot850]

The project 2000 V70 base when bought had a damaged drier but still had some residual pressure in the system. The Condenser is bent courtesy of the PO but did not appear to have any issues as like I said the system held pressure but not much.

I replaced the drier and the local repair shop re-gassed the system. I asked them to add dye to the system as I am not convinced the system is good and if it failed I could find where (my luck will be the accumulator). The repair shop said they cannot add the dye as there is no high pressure connector to inject it into, and it can't be done through the LP side. If this is the case, how do you test the integrity of the system?

I will have to wait until at least Tuesday to take it back to get the pressure re-checked.

I did replace the Schaeder valve on the LP port with a new Volvo part before re-gassing.

Today when driving the car, the AC took a while to come cold, but thought I could occasionally feel warm air. Stopped at a mall, came back out maybe 20 minutes later, started up and the system came on cold fairly quickly. Ran for a while and then switched from re-cycled air to outside and then went warm. Also smelt like old wet socks. Switched the system off, rolled the windows down and maybe 5 minutes later switch the AC back on on re-cycle mode, and it came cold again. Ran for a while and then went to ouside air and was cold for a while and then went warm again.

I am aware of the clutch gap issue, but for those more experienced with AC on the P80's does this sound like low pressure (read a leak) or possibly a compressor issue or ECC issue? I have a couple of spare ECC units and loads of cabin temp sensors (I did clean the one in the car).

Any suggestion where I should start looking for the solution?

Thanks,

Neil.

[wizechatmgr]

Not sure why they can't add dye to the low side... Worse case scenario you slap it on the recovery machine to remove the remainder, pull a vac. after and then inject the dye.

VIDA will get a code from the car if the ECC calls for the compressor to turn on, but it does not build pressure - at least with my '99.

[readallthebooks]

they sell consumer cans that have the dye... and even kits with the dye and glasses and light. unless those are total bunk i dont know why a shop couldnt add dye through the low side...?

[scot850]

Thanks for the replies, but I will talk again to the local repair shop on Tuesday when they return (national holiday tomorrow) and then take it to the dealer if I get no answer that I can work with. The system has been working well since it was re-filled about 2 months ago and just started playing up yesterday. First thing I guess is to get the system pressure tested, and then go from there.

Neil.

[scot850]

Spoke to the dealer and they say they can add dye to the system for leak testing, so maybe they have better equipment than my small local shop. Anyway, it goes in tomorrow for system pressure test, but I think it may well turn out OK. I drove the car today and it was only around 20-25 C and the AC worked perfectly, which would point to the clutch on the compressor being the likely culprit. When I am under the car again next I will check it out, but it works for now and long range forecast looks like lower temps for the most part so we can survive until then!

Now just need to find the bread clip/zip-tie instructions!

Thanks for help guys,

Neil.

[thebull]

In case there is a leak you might need leak detector. They are selling few on amazon and eBay. Price should be in range of $30 to $600. UV Dye is used only for large leaks. Microscopic pinholes causing AC to be dry after 3 days or 2 weeks. Most of the leaks happens from the condensers and could be two or three of them.
The leak detector I have is capable to detect debits of 0.3 ounces per year. The number could be 1 or 2 ounces per year and will do the job for sure. Smaller the number bigger the price. But do not worry to go with cheaper option. If it is working will do the job. For example: my XC90 was loosing Freon in 2-3 weeks. The debit of the leak was big enough to be detected with whatever detector available. Please keep in mind that when the system is cold leak goes slow and more when heats and pressure increase.
Leaks most probably will occur due to mechanical impact, corrosion, faulty installation (bad seal for wrong material for example).
When detector is used it must be inside garage or parking without air draft.
Lets hope it is something else.

[scot850]

Well had the system pressure tested and at around 20-22C it was freezing the nuts off a monkey (repair shop words). They were right as it was the same when I used it yesterday. Had to run several errands around the city (about 50km) and the system worked great for about 45km of that and 3 stops. On the last 5km home same thing, it was about 30C and all of a sudden system stopped blowing cold again. Has to be the clutch out of spec., so once I get a chance (or if the weather stays below 30C! I won't need to this year) I'll shim the compressor with good old zip-ties.

Thanks for the help guys.

Neil.

Mind you if the dealer ever got my 'R' back I wouldn't need to run this car on hot days either (3/4 weeks and counting).

[abscate]

Yeah that's a clutch gap issue. Measure the gap with a feeler first. I'll see how my pink zip ties measure up for giggles

[scot850]

Pink would be nice, they will go well with my red eyes from all the crying........!

Neil.

[erikv11]

Almost any AC issue, first step is always to measure the clutch gap ! It's so easy to do, just reach down there with a feeler gauge. (Yes, hindsight is 20-20 ... )