A/C Leak ? seems very small…not sure I can find

[Josh G]

98 Honda Accord LX 2.3 180K r134a

Looking at a friend’s A/C. It doesn’t cool at all and when I checked the lines for pressure they had none. The leak seems so small I’m not sure it can be easily found so wondering if it’s worth even trying?

Checked for dye and didn’t see much except around the top outside of H/L ports (whether Freon was leaking out of caps or the dye is from someone hooking up a gauge idk…however my car, for example, doesn’t show anywhere near that much dye on the exterior of those ports)

Vaced it down for ½ hr
0-45 min: Vac held perfectly at about 30”
80 min: I checked and needle had suddenly moved to 25”
120 min: Still seems to be steady at 24-25”
150 min: About 21”
180 min: 20″

I would hate to have him buy a drier and Freon if it’ll only leak out again. However, it seems like most people only hold a vac to check for leaks for like 30min and it showed no leaks during that time?

I tested my gauges and know they are capable of holding a vac for at least 2hrs.

Topic

[Josh G]

Here’s the things I’d really like to get some thoughts on…

1) How big of a leak would cause the kind of drop I was getting…thinking it would have to be very small. Could that be from water coming out of the oil/drier and displacing the vacuum? System may have been open to atm for 2-3yrs.

2) I had the thought that maybe the leak is from the valves/caps because the amount of dye there seemed more than normal

3) Thinking of replacing the valves, caps, & drier then charging with dyed 134a because the new valves and caps may stop the main problem and even if it has a small leak it may be so small that it would only require a top off every year or two. I know the system should have 0 leaks, but at 180K is the amount of leakage I’m showing significant???

4) Haven’t been able to find the amount of oil to add for a new drier…have a manual for a minivan that says .71 oz???

[college man]

replace the shradder cores in the valves.If your dropping vacuum
then there is a leak. vacuum breaks easier than pressure.
check out this link.It may help you.

[Josh G]

[quote=”college man” post=77159]replace the shradder cores in the valves.If you dropping vacuum
then there is a leak. vacuum breaks easier than pressure.
check out this link.It may help you.[/quote]

Thanks for the reply. What did you mean by “vacuum breaks easier…” you mean that a system may be better at holding pressure than a vacuum. Which I think I read somewhere (something about certain seals doing better under pressure than vacuum)

Didn’t see the link you posted

I’m a little confused about the vac test though…for example I think I remember Eric saying he would vac test a system for 1/2 hr…but in my case the leak didn’t show up at all until after 1-2 hrs. How how long is good enough

[Its me]

I usually hold vacuum for about an hour, if no leaks, then I charge…… That amount of time has served me well… Also as stated, the schrader valves can be the source of the leak, also ensure to put the plastic caps back on them…

-Karl

[Josh G]

So I think I’ll replace valves, caps, and drier and put a charge in it…I just hope I can find the leak if it’s as small as I think it is.

[Tom]

When you charge it, put in dye, and just enough gas to get the compressor up and running, then search for a leak with your black light.

[Its me]

[quote=”JayMann07″ post=77230]So I think I’ll replace valves, caps, and drier and put a charge in it…I just hope I can find the leak if it’s as small as I think it is.[/quote]

I would recommend also replacing the O-rings where you find them… Give them a little lube with whatever refrigerant oil you are using….

Also, a good investment is a HF refrigerant leak detector if you are ever going to do this type of work in the future… Not a bad price at around $48 before tax with a 20%-25% discount coupon that is easily available… I have used it and it does work….

http://www.harborfreight.com/electronic-freon-and-halogen-leak-detector-92514.html

-Karl

[Bluesnut]

Considering the age of the car, I would suspect a compressor shaft seal might be leaking.

[college man]

[quote=”JayMann07″ post=77230]So I think I’ll replace valves, caps, and drier and put a charge in it…I just hope I can find the leak if it’s as small as I think it is.[/quote]

http://www.ericthecarguy.com/faq/solving-automotive-hvac-problems

sorry about that. Here is the link.

[Josh G]

[quote=”Tomh” post=77234]When you charge it, put in dye, and just enough gas to get the compressor up and running, then search for a leak with your black light.[/quote]

Will do…told him to get a can of 134 with dye already in it.

[quote=”ToyotaKarl” post=77236][quote=”JayMann07″ post=77230]So I think I’ll replace valves, caps, and drier and put a charge in it…I just hope I can find the leak if it’s as small as I think it is.[/quote]

I would recommend also replacing the O-rings where you find them… Give them a little lube with whatever refrigerant oil you are using….

Also, a good investment is a HF refrigerant leak detector if you are ever going to do this type of work in the future… Not a bad price at around $48 before tax with a 20%-25% discount coupon that is easily available… I have used it and it does work….

http://www.harborfreight.com/electronic-freon-and-halogen-leak-detector-92514.html

-Karl[/quote]

Thanks Karl…I do have a one of those detectors in that price range and they do work amazingly well. I plan to use that along with the dye and will try and report my findings. Im just really hoping it’s not evap. or cond. in some hard to see/reach place…we’ll give it a try anyway :whistle:

[EricTheCarGuy]

A very common place for leaks is at the valves themselves as pointed out. If you can hold vacuum but you have a slow leak, then look to the valves for the cause. More info here.

http://www.ericthecarguy.com/faq/solving-automotive-hvac-problems

Keep us posted on how things turn out.

[Author]

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