jw11432

I've just gotten around to trying to charge my AC today. So my system has actually been under vaccuum at -30 for the last several months. But today, the upper condenser connection started leaking like a sieve shortly after the first can started dispensing. Looking more closely, it appears the connection is imperfect. The seal being used is one of those rubber/aluminum(?) washer style?

And here is the connection, you can see that it seals fine at the bottom, but at the top, there's a small gap that I never noticed. Verified the connection is torqued down, of course.

So am I using the wrong seal? Should I instead be using some green rubber o-ring? Very confused by what's happening here.

chem_man

Year, Make, Model, Sub-Model, Engine?

Did you lubricate the seal with anything prior to installation?

jw11432

2002 Silverado LT 5.3

All seals were lubricated with PAG46 before installation. This is the only one giving me grief.

chem_man

Thanks for the requested information.

You might have received a bad seal when you purchased it. My recommendation is to purchase a new one. I tried to determine the part number of that specific seal, but the GM parts sites I use do not list a part number for that specific seal. The best I could come up with are part numbers for 3 seals from Four Seasons, one of which is the seal you need. Here are the part numbers 24402, 24404, 24354. I got these by looking at the hose assembly that connects to the condenser (assuming that the compressor is a Delphi compressor). If your truck has a Denso compressor, then there are 2 possibilities - 24402 or 24404.

NOTE - if there is a muffler in the hose assembly that goes from the AC compressor to the condenser, it is a Delphi compressor. If there is NO muffler in the hose assembly, then it is a Denso compressor.

I would take the old seal with you to a decent parts store (I would say NAPA or O'Reilly) along with the part numbers provided and they should be able to assist you in getting the right seal.

Also, the outside diameters of the sealing washers are as follows - 24402 19.05 mm, 24404 25.4 mm, and 24354 29.46 mm.

Good Luck!

jw11432

That's good information, thank you. I had no idea about the denso vs delphi, so it's good to know I definitively have the denso style.

Unfortunately, I no longer have the original seal. I've never had this kind of trouble sealing an AC system. I did purchase a set of sealing washers with a variety of sizes, with both of the ones you mentioned being contained (within very small margins, anyway: my kit contains a 19.2 and a 25.3 OD.

My biggest concern is the gap that exists between sealing surfaces, which leads me to believe either my part(s) were defectively manufactured or I've somehow purchased the wrong parts and there is a mismatch. Could you verify that my parts compatibility is fine? I am using the FOUR SEASONS 4138NK compressor kit, and the line I purchased is the UAC HA11375C and condenser is DENSO 4770771. The connection in question of course is between the line and the condenser. I don't think there's any compatibility issues with these parts, but this is an unusual problem I'm having.

chem_man

OK, I looked over your parts vs the ones listed in various online catalogs (roackauto.com and 4s.com) and you purchased the correct parts. By the way, you were smart to get the Four Seasons Kits. I've used them on 3 vehicles with zero problems.

Based on personal experience and the photo you posted, I believe that you are having an alignment "problem" between the hose end and the condenser block fittings. My suggestion is to loosen all the joints for that line, remove it from the condenser, verify that the fittings on the condenser and the hose are machined properly (flat and not at an angle), and then slip on the new seal (after lubricating it) and then install it on the condenser and tighten the nut down snugly. Then connect the other end of the hose to where it is supposed to go.

Once back together, the joint in question should be OK. Sometimes the fittings are off just slightly due to the welding process and rather than bending them, I try and let the hoses "correct" the alignment difference.by loosening the various fittings, twisting the hoses a little here or there, and lifting or pressing down a tiny bit on the hoses,



I am attaching a picture of the components of your Silverado's AC system so you can make sure you have the hoses oriented correctly (if it can be installed backwards, I have done it!).

Good Luck and be patient!

jw11432

So I think I actually resolved that aspect by getting a thicker washer. I came across some that have a ~2mm rubber thickness, as opposed to the ~1mm. While the connection was torqued down, I did my best to measure the gap where the washer should sit with my caliper and I couldn't see more than a ~1.2mm gap, and now that I have the new 2mm washer in there, it looks like a far more uniform compression.

At this point, I can only question the attached picture (mostly because of item #7). Is this a diagram of a Delphi system as opposed to a Denso?

The one thing I need to do now is repair the threads on my compressor as when I was torquing down the the bolt of one of the hoses on it (25 lb ft) it stripped. So I'm thinking there's a good chance that my new leak is coming from that. It's a slow leak, losing 2 psi after 20 min, but certainly enough that I want to address it. I've ordered a helicoil kit to remedy it. Looking at my FSM for the torque specs, I think I misconstrued the torque spec for the single bolt/twin hose version of the compressor connector for the individual 2 bolt/2 hoses (which I have), as these appear as though they might be 12 lb ft.

chem_man

Regarding the image being for a Delphi or a Denso system, I believe it is for both. When one looks at the parts listed below the image on the GM parts website I used (https://www.wholesale.parts/), that is where they list both a Delphi compressor and a Denso compressor for the AC compressor and the respective hose assembly for Part #7 in the diagram.

OK on finding a thicker sealing washer. Great!

As far as the threads go, all I can say is oops! Sounds like you are doing the correct thing. But, on the other hand, I would check with wherever you purchased the Four Seasons AC Compressor kit from and ask them to warrant the compressor as being defective from the factory. The threads should have been able to handle being torqued to 25 ft-lbs easily without being mucked up. I did look up the torque spec for that fastener and it is 25 ft-lbs - oops - I see where the Denso compressor hoses are listed elsewhere in the torque specs, and you are correct, 12 ft-lbs is what those 2 hose bolts should be torqued to.. Still, I would try to warrant it as the threads should have been able to handle it.

I had to warrant the compressor on the first Four Seasons AC Compressor kit I purchased from AutoZone several years ago because it would not hold vacuum. I replaced every hose and every seal in the system but it just would not hold vacuum. AutoZone warranted it zero problem, and after I installed it, bingo! the system held vacuum. Manufacturing mistakes do happen.

Good Luck!

mommafrica

Thanks for the website. Needed that!