Author Topic: Vehicle A/C leak. (Read 501 times)

Apache · « **on:** July 15, 2003, 10:42:24 AM »

I have a 1998 Camaro that is leaking around the compressor clutch. Will Castrol Stop Leak, (supposedly designed to stop seal leaks) work? $6 bucks is more appealing to my budget than $425 at the moment.

DiabloTX · « **Reply #1 on:** July 15, 2003, 11:20:52 AM »

Take my advice, and I have plenty of wisdom in this area, I managed a repair shop for 6 years, plunk the money down and get it fixed correctly the first time. Stop leak is just a stop gap measure. Introducing substances in to the A/C system, especially R-134a which is compressed to higher pressures than R-12, is not a good idea. I have a 1996 Camaro thats getting a new fuel pump and clutch disk with master cylinder as we speak. PS-I had the compressor replaced last summer. Hope this helps.

Vector · « **Reply #2 on:** July 15, 2003, 11:31:20 AM »

Is that Castrol ment to use in a/c systems? I've never heard of any kind of miracle repairs. Your -98 Camaro most likely has R-134a refrigerant which uses polyoester or PAG oil. Both are extremely sensitive for moisture (oxygen). If you open your a/c system, you need special tools like;
- gauges
- vacuum pump
- refrigerant
.. and still you have very good chance to get contiminated oil and by that a compressor break.

Small amount of oil coming from a/c compressor's clutch is acceptable. Shaft seal sealing is based on very thin oil coating on the seal. If a/c has been without any usage for few months, this oil coat usually dries out and the seal starts to leak refrigerant. Seal usually starts to hold again after little a/c usage. This is why a/c should be used on every other week or so, even if not needed.

If you shaft seal has a big oil leak, then it should be repaired asap. If oil get inside the electric clutch, it eventually starts to slip, which causes the clutch & shaft seal to get hot, which causes the bearings to seize.

-vector

john9001 · « **Reply #3 on:** July 15, 2003, 11:38:17 AM »

if it is the compressor shaft seal that is leaking, 'stop leak' won't help , the shaft seal is a spring loaded carbon disc.
the stop leak is made for the plastic/rubber lip seals.

if you can find a real tech instead of a parts changer, that shaft seal can be replaced and you can use the old compressor.

some shops like to replace the whole compressor , it takes less skill and they can sell you new compressor.

Vector · « **Reply #4 on:** July 15, 2003, 11:41:11 AM »

Quote

Originally posted by DiabloTX
Introducing substances in to the A/C system, especially R-134a which is compressed to higher pressures than R-12, is not a good idea.

Hi Diablo

Actually R-12 & R-134a has very similar operating pressures. R-12 was perfect refrigerant for a/c and transport refrigeration units (well, ozone layer may have a different opinion). But as a substitute for R-12, R-134a is very good too. Down side is that one must be way more careful when repairing R-134a systems, due the used sensitive compressor oils.
Today many car manufacturers in Europe & Japan are testing a cryogenics systems as a car a/c, using carbondioxide (CO2) as a refrigerant. High side operating pressures are something like 70-100 bars, while R-134a has around 15-20 bars.

-vector

Apache · « **Reply #5 on:** July 15, 2003, 11:55:51 AM »

Thanks guys.

Yes, the Castrol Stop Leak is designed for vehicle A/C systems using R134a. It is advertised not to harm the system, specifically stating the oil in the system. In some of the reading I've seen today, it is the only one that has been tested on "moving leaks" such as one might find at a "O" ring around the shaft.

Agreed, replacing the compressor is the best solution but for a temporary alternative, I was curious if it really worked.

Heck, I'm just a systems analyst. I'm going to have to pay someone to do it but $425! Egads.

DiabloTX · « **Reply #6 on:** July 15, 2003, 12:28:16 PM »

I managed a Mercedes Benz repair shop and I saw the high side and low side guages as the mechanic was adding the freon. The R-134a was always a little higher than regular R-12, not by a huge amount but it was always higher. As for 'parts changers', thats the nature of the beast nowadays. There isn't enough time or profit in rebuilding used parts. There are those that still do it but usually are shade tree or really small independant shops. If I was going to spend the money, which I have, I would just fork out the money and get a rebuilt compressor and clutch assembly but, hey, to each his own. And $425 for a compressor? Thats chump change. I typical nippon-denso replacement with clutch assembly (both rebuilt) on a W124 Mercedes Benz could easily hit $1000.00 or more (that is with a new expansion valve, drier, o-rings, freon, oil, etc...) And don't even get me started on replacing evaporators on MB's, WELL into the 4 figures.

john9001 · « **Reply #7 on:** July 15, 2003, 12:56:36 PM »

well prices for Mercedes Benz and other high end cars are always expensive.

i just did some web crusing for A/C stop leaks, it seems there are about 4 or 5 companys making A/C stop leak products for both 134 and R12, even found a R12 substitute called 'freez 12' that is EPA ok'd.

the products all differ in what they will repair (seals , small leaks). i learn sumthing new every day

good luck on your repair.

PS: the castrol product said it will seal compressor seals.

DiabloTX · « **Reply #8 on:** July 15, 2003, 01:03:14 PM »

MB doesn't make their own compressors, they used the same R4 and A6 models that GM did on early models. The nippon-denso's are different, obviously. Also, since we used an AC-Delco source for our compressors I wouldn't charge MB list price to our customers, I would pass the savings on to the customers.

Scootter · « **Reply #9 on:** July 15, 2003, 02:33:07 PM »

Really can't hurt and may buy you some time, be sure you tell the mech. when the time comes what you have done so he can evacuate the system very well when replaceing the comp.

hblair · « **Reply #10 on:** July 15, 2003, 04:59:26 PM »

Apache, you should be able to find an a/c compressor assy for about 200 at a salvage yard. Install it yourself, you'll just need some o-rings, tools and some basic mechanical skills. Then take it to the local quick lube and get it charged up.

rpm · « **Reply #11 on:** July 15, 2003, 05:13:59 PM »

Do you have an O'Reilley's Auto Parts store near you? I just replaced the a/c compressor on my 94 Explorer and it cost $190 for the compressor. But, in the long run, unless you have ALL the equiptment and tools to replace, vacuum and recharge the system, you will be better off taking it to a shop and having it done professionally. $500 is a shot to the budget, but good a/c is priceless.

For those of you with R-12 systems, Freeze-12 is the way to go when recharging. Be aware that ALL the R-12 must be evacuated from the system before charging with Freeze-12. They will not mix. Freeze-12 runs around $8 a can and you can buy it over the counter. R-12 runs around $30 a can and can not be purchased with out a refrigeration license.