R12 manifold gauge

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eightyfive4WD
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My tercel:: 1985 Tercel 4WD DLX Auto Wagon
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R12 manifold gauge

Post by eightyfive4WD »

Last summer, my kind Vietnam veteran neighbor assisted me with refilling my A/C system using his R12 tank. Unfortunately, his R12 manifold gauge developed a leak during the filling of the system and we aborted the process early. My Tercel's AC system itself is leak-free, after replacing all o-rings and replaceable A/C components, however we only filled my A/C system to approx. (what I would guess to be) 1/2 capacity.
As I am preparing to daily drive my Tercel through another Arizona summer consisting of lots of highway miles, I am still in need of filling the A/C system with another can of R12.

I can source another R12 can locally in Arizona, but I have been having trouble sourcing a manifold gauge set of my own to purchase.
I could pester my neighbor to use his gauge set once more, but I would rather just have a set on hand for when the time comes. I am also in the process of moving, so I want my own tools to utilize for future repairs.

Does anyone here have any recent experience utilizing an Amazon or eBay-purchased AC manifold gauge set to service their R12 system? I see several manifold gauges for sale that claim they work with an R12 system but I am having trouble sifting through the sea of cheap garbage and choosing a set that is actually designed to work with R12 cans. I know the thread type is different in comparison to R134a (I have an R12 can tap on hand).

If anyone here has had success with a gauge set they've purchased online recently, please let me know where you got it from & what your experience has been.

Thank you,
Erik
Last edited by eightyfive4WD on Tue Mar 22, 2022 12:17 am, edited 2 times in total.
1985 Toyota Tercel DLX/Auto 4WD wagon (Daily Driver)
2007 Toyota Tacoma TRD Off-Road 4WD access cab long bed (Road trip/Adventure-mobile)
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eightyfive4WD
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Re: R12 manifold gauge

Post by eightyfive4WD »

I am still very much open to input from others on this matter, but I think I may end up purchasing the $60 Harbor Freight A/C manifold gauge set.
I don't see any horror story reviews on the HF website like I did on no-name product reviews on Amazon, which is my main concern. I just don't want to find myself wasting precious R12 from a cracked fitting or similar while I am trying to refill my A/C system.
1985 Toyota Tercel DLX/Auto 4WD wagon (Daily Driver)
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NWMO
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Re: R12 manifold gauge

Post by NWMO »

I love doing what I can for myself, but tend to leave A/C service to the pros. I believe some will add a dye to the freon searching for leaks and if any are found, recapture, repair and try again. Honestly, I haven’t daily driven a personal car with A/C for years. I’m usually busy with rust repair, engines, transmissions, etc. 😳.

Chris
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eightyfive4WD
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Re: R12 manifold gauge

Post by eightyfive4WD »

A very generous fellow Arizonan & Tercel owner is kind enough to let me borrow his manifold gauge, and he has a spare set he is letting me keep!
They are a bit weathered, so at the moment I am trying to find an HVAC shop who can perform a pressure test of the two manifold gauges, so I do not waste any more of my precious R12 in the process of recharging my system.
Image
Image

The other issue I ran into is that the R12 cans I purchased are "south-of-the-border" cans, with an unusual thread size on the top of the cans. The typical 1/2" ACME thread size found on standard pierce-style can taps will not fit the thread of my cans, they have 1/4" SAE threads. A common enough thread size (the same size thread on all the AC manifold hoses), but I have been hard-pressed to find a can tap with female 1/4" SAE threads on the piercing side. So, I have purchased a replacement side-puncture can tap. The one on the gauges shown in picture #1 has a cracked handle, so I didn't want to take a chance on it leaking during my refill procedure.
Image
Last edited by eightyfive4WD on Sat Apr 16, 2022 9:13 am, edited 2 times in total.
1985 Toyota Tercel DLX/Auto 4WD wagon (Daily Driver)
2007 Toyota Tacoma TRD Off-Road 4WD access cab long bed (Road trip/Adventure-mobile)
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eightyfive4WD
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Re: R12 manifold gauge

Post by eightyfive4WD »

NWMO wrote: Mon Mar 21, 2022 7:15 pm I love doing what I can for myself, but tend to leave A/C service to the pros. I believe some will add a dye to the freon searching for leaks and if any are found, recapture, repair and try again. Honestly, I haven’t daily driven a personal car with A/C for years. I’m usually busy with rust repair, engines, transmissions, etc. 😳.

Chris
I understand your perspective as well Chris. AC work is certainly intimidating, but after rebuilding this Tercel's AC system, it is a lot less difficult than I first expected. Using the vacuum pump & manifold gauges seems complicated too, but after using them a time or two it's really very simple.
UV dye works wonders! I've used it to help me troubleshoot a power steering leak, and there's UV dye in my AC system currently, should I ever have a leak in the future. Great stuff. Would be very very useful for finding stubborn engine oil leaks too, I would imagine.

I'm typically very much a no-nonsense, bare-bones person when it comes to my daily drivers but AC is a must here in Phoenix :mrgreen:
1985 Toyota Tercel DLX/Auto 4WD wagon (Daily Driver)
2007 Toyota Tacoma TRD Off-Road 4WD access cab long bed (Road trip/Adventure-mobile)
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eightyfive4WD
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Re: R12 manifold gauge

Post by eightyfive4WD »

Bit of an update:
Image
No local HVAC shops were willing to perform a pressure test of the manifolds, so I did my own pressure testing with a plastic bucket filled with water, and an R134a self-sealing can to pressurize the manifolds.

Image
The method worked great. I was able to identify leaks in one of the manifolds (the first pictured) at the manifold valves and gauge bases, so that one will need repair before it's put back into service. However, the second gauge set pictured above held pressure, and I was able to use it safely once more on an AC system.

Just wanted to share my process in case it helped anyone else here.
Soapy water spray would work as well but it is much easier to detect small leaks by submerging the manifold in water, in my opinion.
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Re: R12 manifold gauge

Post by Petros »

it depends what is leaking, but typically it is just a standard o-ring, or seal that needs to be replaced. a simple fix. OTOH, if a fitting is cracked, it will have to be replaced. t hat is less common on the older commercial quality gauge set.
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eightyfive4WD
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Re: R12 manifold gauge

Post by eightyfive4WD »

Petros wrote: Sat May 07, 2022 7:36 pm it depends what is leaking, but typically it is just a standard o-ring, or seal that needs to be replaced. a simple fix. OTOH, if a fitting is cracked, it will have to be replaced. t hat is less common on the older commercial quality gauge set.
I plan to pick up some hvac o-rings this weekend, and after I get caught up on other vehicle maintenance I will perform the repair on the manifold gauge set and report back on the leak test! I agree, not expecting to find any cracked fittings on this older, high-quality manifold.
1985 Toyota Tercel DLX/Auto 4WD wagon (Daily Driver)
2007 Toyota Tacoma TRD Off-Road 4WD access cab long bed (Road trip/Adventure-mobile)
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