cukaracha

Hey guys,

I very recently replaced the A/C compressor on my 2000 Si. I used an OEM Denso compressor and checked that the system it held vacuum for over 24 hrs. I filled 'er up with freon and made sure to use a manifold gauge set to ensure high/low pressure was within range given ambient temperature. I also replaced the receiver/drier and all gaskets, and tightened all the bolts to torque specs.

Everything seemed fine, but it turns out my A/C system has now developed a very bad leak (not sure when it started). I haven't checked the freon level, but the compressor clutch isn't engaging, so I'm guessing it's very low.

I checked with a UV light (freon had dye) and found a few major leak areas:

1) compressor body and splash guard beneath it is speckled in dye
2) suction valve plate has a layer of dye
3) area right behind the right headlamp is COVERED in dye. this seems to be the biggest leak area.


The only thing that struck me as odd when I did the repair was that I had to use almost two full 12oz cans of R134a when I filled up the freon.


Any clue what went wrong?

ezone

What would the source of this leak be?
What would the source of this leak be?
The headlight cannot leak freon or dye. What would this source of the leak be?

Did you have to swap the suction valve plate from the old compressor? Did you use the new gasket?
Could this have sprayed dye everywhere you found it?

cukaracha

I swapped the old suction valve plate over from the old compressor and replaced the gasket with an OEM one when I did.

Tried looking for the sources of leaks with a UV light at night but I couldn't accurately pinpoint the sources. From what I can see, three of the four bolts that hold the suction valve plate and one of the hoses' bolts have distinct dye rings.

Referring to this picture:

The circled part has the most dye on it, so that could be the source. But the hoses themselves look mostly clean. It doesn't appear that the hoses are leaking anywhere else either, and the receiver/drier is also dye-free.

Based on how the dye is distributed on and around the compressor as well as behind the headlamp (see above pic), it looks like dye got sprayed around quite a bit and there was enough to allow it to drip down onto the splash guard.

That's the best I've gathered so far. Please let me know if you need more details.

ezone

Based only on the picture, I might suspect either of the lines could be leaking under that rusty clamp.

Try adding only enough freon to put a few PSI in the system (NOT a full charge) and spray soapy water on the lines and look for bubbles?

cukaracha

I'll check that when I get a chance. Is it common for the system to develop a leak even after it's able to hold vacuum?

As for the suction service valve, I'll see if the soap water test can isolate the source. In the meantime, any clues?

ezone

It's unusual but certainly not impossible. Think of how a one-way check valve works.

Also some things may only leak after sufficient pressure has built up, which may be your case.

cukaracha

Thanks for the replies and help so far.

Now that I think about it, it appears that the two leak areas are around where the hoses interconnect, but not along the hoses themselves. Is it likely that the gaskets there are worn from age (although this wouldn't explain the leak around the compressor since I replaced the gaskets there)?

ezone

I should have said something like, a vacuum check only checks for gross leaks that occur under a vacuum. Just because it passed one test doesn't necessarily mean all is well and good.


Maybe. Rubber O rings take the shape of their fitting and can eventually harden into that shape, and it's always possible to damage fresh seals during installation. See what pressure + bubbles can tell you and go from there.

cukaracha

I haven't gotten around to checking with soap water but I hope to have some time on Sunday to do so.

I went and checked the content by weight of the R134a cans that I used. It looks like each them contain 340g, which mean I used about 700g in my system. According to the manual, the system requires 600-650g of refrigerant.

Why would the pressure reading remain in the acceptable zone even though I clearly overfilled the system? Likewise, which is the more accurate reading?

ezone

340+340=680, minus what the system can't pull out of the cans...... It may be close to correct.

cukaracha

Thanks for the reply. Assuming that the hoses are leaking at connecting points, will it suffice to replace the gaskets?

ezone

Each fitting has O ring seals, and yes that is the normal piece that would fail.
Of course inspect while apart, no cracks or corrosion that would compromise the ability to seal.


Note, the O ring seals for an AC system are special material (usually Neoprene or HBNR?). If you don't have any, take yours off and take them to a good parts store, ASK for the big box of AC O rings you can choose from and match them up.

Or, your local Honda store probably has some but you might need to pick out the right ones from a miserable picture.

cukaracha

Okay so I finally got around to doing the "soapy water test." The leak on the compressor was immediately obvious (one of the hoses was spewing so much you could hear it after turning off the engine).

However, the second leak area by the right headlamp didn't show any bubbling whatsoever. I even dug around under the hoses and inside the insulation, but I couldn't find anything. I had the A/C running for about 5 mins but I wasn't able to determine to leak for this area.

Any suggestions?

ezone

Fix the obvious leakage, wash off all the UV dye, recharge and see how it goes?

UV dye staining can be tough to get washed off.

cukaracha

Thanks for the reply. The soapy water I used did some of the cleaning and I also used carb cleaner. It looks pretty clean now.

I was thinking of just replacing the O-ring of that hose connection (behind the headlamp) and hoping for the best. But it wasn't obvious how to take the two sections of hose apart. Maybe you could explain that to me?


Thanks again.

ezone

Each pipe fitting has two hexes for wrenches. Use a pair of correctly sized wrenches together to unscrew the nut.

One wrench holds the solid part still (the one hex attached to the exposed threads is rigidly attached to the pipe and should not be allowed to move), the other wrench moves the nut.

HTH

cukaracha

Alright then, I'm going to replace the O-rings on the hose connections in the picture as well as the leaking one on the compressor. I also bought a scale to measure how much freon I'm putting into the system as an added measurement in addition to using my manifold gauges. Hopefully all goes well this time.

Thanks a lot for all your help, ezone!! I really appreciate it!!

cukaracha

Quick update. Replaced the O-rings and noticed two faulty ones. Put everything back together and it seems to hold vacuum. Charged 'er up enough to get the clutch to kick on and she seems to be holding pressure with no noticeable leaks. So far so good. If pressure maintains when I check tomorrow, I'll fill up the remaining amount of freon by weight and hope for the best.

Once again, thanks a lot, ezone!!

ezone

YW.
Crossin fingers for ya!

cukaracha

Update #2: I charged up my A/C system again, but this time following weight spec instead of High/Low pressure. At 620g, both the High and Low pressure readings were below their respective lower bounds. As such, I'm quite convinced that I overcharged the system last time.

Thanks again for all the help!!

cukaracha

Another update:

No leaks at compressor, but I'm certain that changing the O-ring didn't fix the leak behind the headlamp. From the looks of it, I'll need to replace the pipe (part #80343S01A01), which is leaking somewhere behind the insulation.

On ebay, this part sells for $19 (UAC brand) whereas OEM costs $35 + shipping. For a pipe, is OEM significantly better or can I get by with aftermarket?

ezone

I might chance it

cukaracha

According to the information on the freon cans I've used, each can contains about 2oz of "lubricant". Seeing how I've already used 4 cans total (making it 8oz), what's a good way to flush out all the oil before I recharge it yet again after I fix the pipe?

ezone

I'm not sure what's available these days, regulations have been changing fast.....Parts stores used to sell AC flush kits that use R141b as the solvent, and an air gun nozzle...Check NAPA and others?


If I read my service info correctly, the entire system is supposed to hold 5-1/3 oz of oil....so unless the freon leaks also let a whole bunch of oil leak out, you likely have far too much oil in the system as it stands now.



Quote from some service info:

If there’s too little oil in the system, the A/C compressor can make noise or possibly fail. If there’s too much oil in the system, the system’s cooling capacity is reduced.

So you can't get rid of all the oil and expect one freon can with 2oz to be sufficient.

I think that one method could be to flush all the oil from the system, plus remove the compressor and dump all the oil out of it so you have a completely oil-free system....then start over fresh--- with installing the correct amount of NEW oil into the compressor and reassemble and charge the system with plain freon, no extra oil.
Or math it out so it comes out right LOL

cukaracha

When I found the leak areas, they were definitely oily to the touch, so I'd imagine that some oil leaks out with the freon. Moreover, the entire leak area is covered in dye, but I'm sure there isn't THAT much dye in the cans. This would mean that the dye colors the oil, which in turn stains the leak area.

Now the question is, how much oil leaks out by the time the entire system is freon-less? I'd imagine that more oil would leak out if the A/C was running?

ezone

SOME. How much leaks can vary a lot depending on circumstances.
A running system pumps a mist of oil along with the freon throughout, and oil pools in the low areas of a system that is not running.

Our tiny little vials of UV dye say 0.06 oz on them.
A little dye goes a long way.

cukaracha

Alright, so I opened up the foam insulation around the smaller pipe (in the picture) and I found the leak - a little hole that was dripping oil, freon and dye.

Is there any method of fixing this besides replacing the entire pipe or splice? I'm trying to avoid having to evacuate the system again. Perhaps self-fusing silicone tape?

ezone

Just replace the leaking pipe and start over.

cukaracha

If I flush the system, will that remove the compressor oil as well? Another way of phrasing that question is, is the compressor oil isolated from the "system" oil (oil from the cans)?

ezone

I would not want to purge flush solvent through the compressor. I would disconnect the lines from the compressor.

As a system, the compressor is not isolated but it is probably designed to keep an amount of oil inside it for lubrication (if it ran dry it would self destruct), and it is in a 'low spot' so oil would tend to stay in it at rest.

I think you would have to remove the compressor from the engine, turn it upside down and rotate the clutch plate by hand several times to get the majority of the oil out of it.



You may need to open the lines at the evaporator also, the expansion valve may make it tough or impossible to flush.

Remember to replace all O rings wherever you open up connection points.