Now I have a leak !!! 1998 Frontier

[Cusser]

Well, Monday, returning to Phoenix 1pm, the AC stopped working in the Frontier, blower motor blew out hot air (projected to be 117F here today). About 10 minutes later cool air returned, then stopped again 10 minutes later, as I was approaching home. So far, all I've done is confirm that compressor was not turning when the hot air was blowing.

So trying to figure when/if is a good time to work on this, scheduled to go back up north Wednesday, and 12F projected for tomorrow. Heat warning extended until Saturday evening now. I might "have to" take the B2200 up north, driving without AC when it's this hot (figure 140-150F 4 feet above the pavement) is a real chore.

I need to see if compressor is getting voltage when the AC clutch stops engaging, that's #1. Since it started blowing cold again,
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Braved the 117F afternoon temperature, took a look see. AC clutch was engaged then; saw oily residue on the high pressure rubber line from compressor to condenser, actually found a tiny pinhole leaking refrigerant and oil when the AC was operating...
Lower part of the hose is on the right in this picture, flowed down by gravity.


This is dealer part 92490-3S501 which sounded discontinued when I called Courtesy Nissan Parts in Texas. However, for half that price ($58) there are aftermarket units available from your local O'Reilly. http://www.oreillyauto.com/site/c/detai ... bilityTab_


So looks like "AC fun" Wednesday morning !!! Since the system still contains refrigerant (so no air got in), I will NOT be replacing the drier. I will add 1 - 2 oz. refrigeration oil that has some UV dye in it, then evacuate, check vacuum, and add R134a (NO SEALERS OR CONDITIONERS !!!).
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I'm not sure that the pin hole actually leaks when AC is not in use, as static refrigerant pressures might only be like 90 psi. But when operating, the high pressure line can get to 280 psi. This rubber line (see photo in earlier post) is very close to where one checks the oil, so there was no oily residue there just a week or two ago, this was pretty obvious; a little oil actually pooled up in the "cup" of the crimp. Many times one would be surprised how long it actually takes for a tiny leak to cause an AC system or tire to leak.

High pressure line issues are somewhat common with the old Frontiers, from what I've read, I'll tackle this early tomorrow morning. Good news is that the forecast high temperature today was reduced from 120F to 119F !!!


On my 1988 B2200, I had its high pressure line repaired for about $50 over a decade ago, that leaked at a crimp. What bugs me on the B2200 is that it has leaked about 6 oz. R-12 since last summer, and I cannot find the leak even though the system has UV dye in it (and I've got light and goggles) and an electronic detector. Prior to replacing the compressor and drier Oct. 2014 with brand-new, there were no refrigeration leaks for over a decade, so I "figure" something there "must be" the reason for the leak, but I've checked over the entire system for leaks several times (and once by a shop) and can't find a smoking gun. So I'll likely just add another can of R-12 this year from my stash.

[Tim]

I can hook you up with a guy in Chandler that can rebuild the line. But UAC will likely have the line for the same cost.

Discharge
http://www.ackits.com/nis-xtrra-24-4c-0 ... A%2010693C

Suction
http://www.ackits.com/index.php?route=p ... A%2011209C

[GM Tech]

Your a/c inop is not due to your leak if you have intermittent cold air!! Two separate issues! The next time you have hot air blowing- tap on front of compressor clutch driver- see if it engages- if so you have the infamous wide air gap scenario...and we can expand on it later..

[Cusser]

Your a/c inop is not due to your leak if you have intermittent cold air!! Two separate issues! The next time you have hot air blowing- tap on front of compressor clutch driver- see if it engages- if so you have the infamous wide air gap scenario...and we can expand on it later..

Monday afternoon, driving from Prescott (100F) down to Phoenix (117F), the AC clutch did stop engaging and temperature in the cab got so hot I had to open the window. I was actually figuring that it was an AC clutch issue (I don't have a wire to a dash light on it to show me when AC clutch is getting voltage, like I do on my '88 Mazda truck) and was going to pursue that, but then I saw the oily residue and confirmed pinhole leak on that high pressure line.

Yogi Berra (or some other backyard mechanic) always said: "Fix FIRST what you KNOW is bad", so that's what I did. So mid-day yesterday, I drove it back from 117F heat tot he cooler 104F in Prescott, and the AC worked fine, 100 mile drive. I did notice a few times that the AC compressor disengaged, but it re-engaged before the vent air became warm (where it was HOT Monday afternoon), seemed like that was normal evaporator de-icer switch operation. Anyway, it cooled fine, and this is definitely a heat wave here, weather has "heat warning" in effect until Sunday night. I also checked the two new line connections for oil residue after the drive, they were fine.

In this type of Arizona heat, if one turns off the AC switch, you definitely feel the air being warmer and uncomfortable within 1 or 2 minutes. That did not come close to happening yesterday. But I'm aware that with 18 years and 219K on this Frontier AC system, that something like an air gap or de-icer switch may be involved. Yes, that Phoenix temperature Monday afternoon was ungodly hot and (maybe?) affected the ability of the clutch to engage, but that was also on freeway driving so good air flow, not dependent on the fan clutch.

Actually, hoping it's not an AC clutch or gap issue, as I don't think the Frontier has clearance to do those while the compressor is still in the truck and lines still connected (which I could do on my '88 Mazda truck).

But I fully understand that the pinhole could've been a completely separate issue; just hoping all is well now. I'll add to this post if the condition changes, thanks.

[Cusser]

Update, still an issue: I drove it 100 miles on highway that day in record heat back to Prescott area, AC on. Drove it to senior softball Thursday, AC on. Monday Mrs. Cusser drove it 250 miles on highway in 110+ F heat, AC on. AC did NOT switch off, was very comfortable even in 110F+ heat.

This morning, she used the Frontier to drag the horse arena, AC on. All of a sudden refrigerant and oil comes spitting out, looks like a leak at the O-ring on at the junction of the high pressure line to the compressor, lost refrigerant and some refrigeration oil. I replace with one of the new O-rings, oil it properly, add 3 oz. of PAG 100 oil, pull vacuum, start adding refrigerant. Partway through the second can of R134a, leak at same place again; high pressure reading at that point was only 100 psi, so sure doesn't seem like an obstruction in the drier or expansion valve, that would cause abnormally high pressures. The single hold down bolt is down as far as it can go, the metal of the end of the fitting is flush on the compressor (there is no locating pin on this end).

It seems like this high pressure hose is only from one manufacturer, in China, sold at both Autozone and O'Reilly and others as different brand names, all with same sticker with Texas address and stating made in China. This part has been discontinued through Nissan.

Unless I get a brainstorm or help from others, I'll be searching out slightly-larger green refrigeration O-rings tomorrow.

Thanks.

[Cusser]

OK, think I got this figured out, the clue came to me while I was sleeping (and did not involve Mrs. Cusser), see what I posted earlier:

[QUOTE=Cussboy;189050] The line came with 2 extra O-rings, too. [/QUOTE]

Those are not EXTRA O-rings, those are necessary/required O-rings. The male fittings each had a channel which had a new O-ring in it (covered by a protective cap) when received. There's a tiny bag containing two additional green O-rings, and I thought they were extras, STUPID ME (of course there are no instructions with this, or in the service manual).

So I took a second look, more careful this time, and these are actually a different size O-ring, like equal in o.d. to the end of the male fitting. So I think they just go in the recess at the top of the compressor and on the condenser before the male fitting gets installed. Except for once with my 2005 Yukon (where I did not encounter this type of fitting design because I didn't change out its accumulator back in 2015), I've not done any AC work on anything newer than the '88 Mazda before, and the B2200 doesn't have this more-modern type of fitting, so I was just inexperienced.

The "bagged" O-rings look too small to get stretched over the male fitting, and besides could maybe get stuck in that channel where the other O-ring is, think they would've been factory installed there if that was the purpose/design.

A re-check of the electronic version of the Service Manual (page HA-47) shows a diagram and lists two O-rings for each fitting (and their sizes) but does not show exactly where the 2nd O-ring (size 12) goes. So I think the "extra O-rings go in the bottom of the recesses.

[Cusser]

Now, this morning: I'm not so sure a second O-ring gets used, I may have read the cryptic Nissan diagram wrong, the one square with the "12" might be the wrench size, the other square with the "12" the O-ring size. Apparently the groove for the O-ring is called the new way in the service manual, and a new size 12 of slightly different dimensions is used. Prior to that the O-ring seal was made at the flange. I might have to call hose manufacturer and ask why there's 2 O-rings in a little bag.

I called manufacturer of the hoses (Four Seasons/Murray), tech person says the two O-rings are just extras, that he gets calls asking about this all the time. I see online that Amazon reviews of this same refrigerant hose are 5 stars (3 reviews), the 3 folks said worked fine.

This is my last try, getting tired of this, and very frustrated. System holding vacuum right now, will try to fill later. It's not like the high pressure is over 300 psi when this has happened previously; seems like the fittings ends do not seat as flush as on my 2004 Frontier, which uses a different high pressure line.

If I don't get this working and fixed today, will take to repair shop in 2 weeks. Where I am now there's a dedicated auto AC repair place, but that's 40 minutes away, and I don't want to spend all day there either so would require substantial time involved with 2 trips there, would rather take to a guy I know and trust down in Phoenix.

[Cusser]

Status: right now holding refrigerant and AC is working. But AC also worked from last Wednesday until Tuesday (when I had considered it "fixed"), with over 350 miles driven with AC on, too.

So - so far - this means nothing. Time will tell....

[Cusser]

[QUOTE=Cussboy;189126]Status: right now holding refrigerant and AC is working. But AC also worked from last Wednesday until Tuesday (when I had considered it "fixed"), with over 350 miles driven with AC on, too.

So - so far - this means nothing. Time will tell....[/QUOTE]

The issue is that I can't get the end fittings of the hose to fit into the recesses of the compressor and condenser 100% flush, there's like a 1/16-inch gap when I use a mirror and look, on the side opposite the bolt. So I think this will leak refrigerant again. The O-ring itself it NOT visible through this gap. I don't feel like trying to hammer on the fittings ends, plus access there is not so good.

Any thoughts? Thanks.

[bohica2xo]

Still have the old hoses?

Rebuild them.