98 S70 N/A 5-Speed: Complete A/C job (yay!) not holding a vacuum... (sigh!) How do I troubleshoot this?

Post by **theWIFES_S70** » 22 Sep 2018, 23:43

This has been a job about three months in the making... Finally got around to tackling the job today.

I replaced all the lines and hoses, the evaporator, dryer, all o-rings... My god, this job hurts! How do you guys with giant hands replace those A/C lines on the Condenser?

I pulled a vacuum for about 30 mins (with 4 month old vacuum pump oil!), pulled it down to 30 bar. But then, it dropped down to 25 five minutes later... I had to leave for dinner so I don't know how much further it went down.

How do I get troubleshoot this? Do I fill it with freon, add dye, and then figure it out the old fashioned that way? Is there an o-ring that frequently get pinched and/or forgotten? I thought I was careful...

Post by **abscate** » 23 Sep 2018, 06:01

How are you watching the drop? Is that with the pump attached but turned off?

25 is no good. It should hold a solid pegged 29-30

You replaced every oring you touched, right? Some of them are easy to misalign if you don’t pay attention

Post by **theWIFES_S70** » 23 Sep 2018, 10:37

abscate wrote: ↑23 Sep 2018, 06:01 How are you watching the drop? Is that with the pump attached but turned off?

25 is no good. It should hold a solid pegged 29-30

You replaced every oring you touched, right? Some of them are easy to misalign if you don’t pay attention

I'll try pulling a vacuum again. I'm not sure if I closed the gauge before shutting off the vacuum. (My dad was hungry and wanted to go out to dinner already.

Two connections and o-rings to condenser, are perfect.

O-rings to compressor... not so sure. When I pulled the hoses, didn't see any o-rings so I installed my new hoses without any o-rings saying, "okay..." Only to then find o-rings still on the old hoses. (Hello another 2 hrs of work!) I installed new o-rings onto the compressor, lubed and everything, and installed the hoses. Like I mentioned, this was such a pain to do! I am less confident about these o-rings.

Hard lines with double o-rings and trombone fittings... got them to fit. So they are fine. Caveat, I didn't really know you had to reinstall them with the removal tool. (This is literally the only car on Youtube that requires the removal tool to reinstall these lines... why Volvo!) I tried to shove in the lines without the tool for a while before taking a month off and returning to this job. I am wondering if I broke my evaporator somehow...

Hard lines were new and had o-rings installed already. The large nut is tight. I'm pretty confident about this one.

The two sensors (replaced those o-rings). Pretty confident about those, too.

The Dryer... Sheesh... I was able to drop it, and get a wrench and some Channelocks on it. Not 100% confident about it. But I think I got it.

Post by **abscate** » 24 Sep 2018, 10:36

You have to seat those O-rings before you get the fastener started or some of them will get caught in the threads..

I think I have a picture of when that happened to me once..

yeah, on this page - one of the hard lines up at the EVAP firewall rolled in the groove, and snapped.

viewtopic.php?f=1&t=56005&hilit=1999+v70+t5&start=30

Post by **abscate** » 24 Sep 2018, 13:39

Oh yeah, I hope that vacuum was 29 inches Hg, not bar.

Those negative pressures ripple the space time continuum and wreak havoc..

Post by **Ozark Lee** » 24 Sep 2018, 19:10

I have had bad manifold gauge set hoses cause an apparent vacuum leak. To eliminate that variable you can pull the vacuum and then remove the hoses and walk away for an hour or so. When you plug the manifold gauge set back in you should still be under vacuum.

Depending on how good you are at getting the connector on and off you might lose a fair amount of vacuum but if you verified that the vacuum held you can pull the vacuum again and then immediately charge the system.

...Lee

Post by **abscate** » 24 Sep 2018, 19:52

You can close off the low pressure port on the car, leave it overnight.

In the morning, pump it down while leaving the low side port closed

Now you need to go into high awareness mode with your ears. With the pump running, open the low port, listen for a change in the pump noise, from wwwwhhhhirrrrr to Wuckawhuckawhucka

If it just whirs, the vacuum has held overnight.

I’m actually sourcing parts for a full scale vacuum gauge on mine

Post by **theWIFES_S70** » 24 Sep 2018, 23:04

Thanks for the suggestions, fellas. Will get to this over the weekend and see how the vacuum is doing. I hope there's no pinched o-ring. Taking it all apart and doing it all over again would be such a pain. Luckily, don't think the wife will need A/C till next Spring at the earliest!

And, not driving the car for a month made my power steering stiff again. Will need to refresh that ATF again!

Post by **theWIFES_S70** » 07 Oct 2018, 21:13

Finally got around to pulling a vacuum on my A/C system again. This time for 40 mins! I followed all the correct steps and, while I hoped beyond all hope!, it was pretty evident there was a pretty big leak somewhere in the system. (Dropped close to 10 bar in five minutes...)

Will disconnect and drop drier and drier hose and tighten them... Hopefully it's that. Otherwise, it's probably the evaporator I broke trying to shove in my trombone fittings without a disconnect tool...

Post by **abscate** » 08 Oct 2018, 04:55

The Evap is really hard to break, I doubt it is that.

You can also test it in place, too.

Everything else is a pain but at least the dash stays in