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Up Topic American Welding Society Services / Technical Standards & Publications / A/C accumulator on a big chevy truck
- - By jwright650 (*****) Date 06-21-2012 13:35
Any idea what grade of aluminum that may be made of?

I was asked by my maintenance guy if I could TIG weld up a small hole where something had rubbed against the side of it. He plans to take it off of the truck(all of the gas has leaked out anyway) and bring it into my office sometime for me to look at.
Parent - - By rlitman (***) Date 06-21-2012 17:50
Seriously?!?

They're like 20 bucks new, and come sealed up with a properly prepared and fresh desiccant bag inside.
Once you open up the system to work on it, or when the system vents its charge, as it has in this case, you're supposed to just toss that whole assembly, and put a new one in before recharging the system.
Oh, and tell him not to cheap out, and to replace the HNBR o-rings when he has it open too.

This is not something you want to repair (if I wasn't clear enough already).
Parent - - By jwright650 (*****) Date 06-22-2012 14:18
Yup, gonna repair it....I think you have confused the drier for the accumulator. The accumulator is on the low pressure side with the large tubing welded to it and has the low pressure switch screwed into one of the fittings. I can assure you that it is more than $20 to replace it and the system will need a vac pulled and a recharge(oil and refridgerant), so breaking the lines aloose to repair isn't that big of a deal. I just wanted to know if the filler that I have here on hand(4043) is what will be required to seal up that small pinhole.
Parent - - By rlitman (***) Date 06-22-2012 17:53
The accumulator IS the dryer in a vehicle.  It serves double duty, and it IS important that you replace this every time the system is opened up.
It is ESPECIALLY important to replace it if the system leak is on the vacuum side of the system, as you are guaranteed to have pulled air and moisture in now.

Do you have the part number, or know the make and model of the vehicle?  These may be $50-60 in the parts stores, but are typically $20-30 online.
At $30, it really isn't worth the argon and your time to mess with this.

It's just an aluminum can with some ports, and a desiccant bag inside, but you cannot "recharge" the desiccant yourself.  When you buy a new one, they are sealed up with fresh desiccant.  You don't pop the seals until you're ready to install it.  If you re-use the contaminated desiccant, you risk causing damage to the system after you re-charge it.

As for welding.  Have you read threads about the dangers of welding around brake cleaner?  Refrigerant is just as dangerous, and just as likely to create phosgene when welding around it.  Thought you'd want to know that.  I'm not sure what would happen to the desiccant or its bag, as you welded on the can, or if either would outgas something else dangerous too.
Parent - - By jwright650 (*****) Date 06-25-2012 18:03
You're right...now that I've looked at it, I advised them to buy a new one. The motor in the truck has gone sour and they are going through that too. Truck only has 184K on it, so I don't understand why the thing is wore out so quick...I thought those Cat diesels run into the 100's of K's of miles before having to be gone through.
Parent - - By rlitman (***) Date 06-26-2012 14:36
Well, I just hope I saved you a headache.
Best of luck with this one.
Parent - By jwright650 (*****) Date 06-26-2012 15:40
I thought it was like the older systems where the drier was a seperate canister that was plumbed inline. I'm glad you were persistant in trying to raise my awareness, otherwise I may not have gone out there and actually looked at the truck, just welded up the hole and handed it back off to the maintenance guy.
Parent - - By Cumminsguy71 (*****) Date 12-26-2012 22:15 Edited 12-26-2012 22:28
I have to disagree on the replacing the accumulator/dryer everytime the system is opened. We rarely replaced them unless there was a direct issues with it. If it's your car and your buying an Autozone compressor and want to keep your warranty on your new compressor then replace it and the orifice. If not then there is no need to replace it. I changed out a bunch of compressors at the dealership and opened up systems under warranty and as customer pay and only replaced the dryer twice. Both times the compressor grenaded and filled the system with metal. Replaced compressor, dryer and that was it. We installed an inline filter to catch any metal in the system before the orifice. All of these repairs were approved by General Motors and standard practice. That was my job at the dealer, me and one other guy took care of all a/c and heat problems.

As far as welding the dryer, just replace it. With the dessicant in there you might as well just relace it because if it has a hole in it then it sounds like is pretty old so you might as well just replace it. It might be $50 or something but not worth welding it up. I think replacing the dryer everytime was something made up by the parts suppliers, kinda like oil changes every 3000 miles. Need to sell more parts/oil so put these little "need to" things in everybody's mind so they'll get all worked up over it and do it because "the internet said". LOL!
Parent - By jwright650 (*****) Date 12-28-2012 01:26
It was replaced, something rubbed a hole in it....the truck isn't all that old, just had a bracket or something rubbing on the side of it.
Up Topic American Welding Society Services / Technical Standards & Publications / A/C accumulator on a big chevy truck

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