I'm a DIY guy (just wrapped up starter and valve cover replacement), but always assumed you needed special equipment to do a/c repair. Apparently I can rent the manifold gauge set and vacuum pump. Is that all that's needed? How to you find a leak? Is the DIY route fairly doable, or should I bite the bullet and take it to a shop?
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I DIY all my repairs, including AC. I started out with the set of harbor freight manifold gagues, until i realized they werent very good. I invested in a good set (maybe $150ish) and still using the Harbor Freight Vaccum pump. I also bought Dye and a UV light to find leaks. I have successfully repaired AC in other cars, thankfully ihave not had to do any on my 100, but I have the tools and skills to do it when it happens. I learned eveyrhtign i need to know from watching YouTube videos. I have no formal training.
here is a good one i woudl suggest to get you started
here is a good one i woudl suggest to get you started
- Thread starter
- #3
Thanks, that's reassuring! Do you have recommendations for the good set of gauges, and does the uv light and dye matter quality-wise?
uv light dosnt really matter, as for the uv dye just make sure that its for ac systems. there uv dye for oil and it will not be compatable with the ac system
I was in your shoes a few months ago and decided to DIY it. Similar to you, I DIY all mechanical work but had not touched AC before. Definitely a learning curve but worth it. I used free vacuum pump and gauges from the auto parts store. The problem turned out to be a bad schrader valve on the low pressure side, very easy fix but hard for me to diagnose because it held pressure and vacuum with the gauges attached! Don't overlook those if you dig into yours.
I now have a leak in my rear AC line around one of the brackets. I added oil with dye in it during my last repair (also did new desiccant drier) so I was able to find the leak using a UV flashlight and blue light glasses. This time I am replacing the rear line with rubber line instead to eliminate the known weak points on the rear AC line. Between the repair this summer and the upcoming one this fall I will have about $60 into r134a plus another $90 in rear hose and $40 in oil, valves, and drier bag. I never got a quote from a shop, but I suspect this is significant savings over bringing to a shop twice and I have learned some new skills. I could now fix a friend's AC for the price of only supplies with the help of a parts store loaner program.
The Autozone loaners are for 90 days (or longer if you ask) which is much better than O'Reilly which is 48 hours. That said, O'Reilly has better manifold gauges and (at least near me) 10000x better service.
I now have a leak in my rear AC line around one of the brackets. I added oil with dye in it during my last repair (also did new desiccant drier) so I was able to find the leak using a UV flashlight and blue light glasses. This time I am replacing the rear line with rubber line instead to eliminate the known weak points on the rear AC line. Between the repair this summer and the upcoming one this fall I will have about $60 into r134a plus another $90 in rear hose and $40 in oil, valves, and drier bag. I never got a quote from a shop, but I suspect this is significant savings over bringing to a shop twice and I have learned some new skills. I could now fix a friend's AC for the price of only supplies with the help of a parts store loaner program.
The Autozone loaners are for 90 days (or longer if you ask) which is much better than O'Reilly which is 48 hours. That said, O'Reilly has better manifold gauges and (at least near me) 10000x better service.
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I DIY AC on older cars for sure. Here is what you need to understand:
1. If it's simply a leak - look at common places for dirt build up. If you don't see any - it might be one of evaporators.
2. Gauges useful for diagnostics, but in case of leak, I really don't use or care about what they show anymore.
3. Once leak fixed, you need to vacuum system and make sure vacuum stays. Easy enough. Use Nylog on connectors (o-rings)
4. Charge by WEIGHT. Don't look at gauges. There is different modes, temperature, altitude, etc. Don't bother. Just charge how much it should be. You know how much in a can, just eyeball last can, thats it!
5. Oil, Oil carried in a system, most of it in compressor and then it's spread out around. If you replace just a line - there is probably 1/4 oz oil in there - don't even worry about it. Because otherwise - you need to make sure you buy correct PAG or ester (whichever it is) weight oil. Too much oil is not good either.
So, as you see - no big deal. Leaks is easiest because all you do is find a leak, fix and vacuum/charge.
Only problem is - it's illegal to vent refrigerant to atmosphere. Shops have recovery machine. But if all your refrigerant already "lost" due to leak - you are OK
1. If it's simply a leak - look at common places for dirt build up. If you don't see any - it might be one of evaporators.
2. Gauges useful for diagnostics, but in case of leak, I really don't use or care about what they show anymore.
3. Once leak fixed, you need to vacuum system and make sure vacuum stays. Easy enough. Use Nylog on connectors (o-rings)
4. Charge by WEIGHT. Don't look at gauges. There is different modes, temperature, altitude, etc. Don't bother. Just charge how much it should be. You know how much in a can, just eyeball last can, thats it!
5. Oil, Oil carried in a system, most of it in compressor and then it's spread out around. If you replace just a line - there is probably 1/4 oz oil in there - don't even worry about it. Because otherwise - you need to make sure you buy correct PAG or ester (whichever it is) weight oil. Too much oil is not good either.
So, as you see - no big deal. Leaks is easiest because all you do is find a leak, fix and vacuum/charge.
Only problem is - it's illegal to vent refrigerant to atmosphere. Shops have recovery machine. But if all your refrigerant already "lost" due to leak - you are OK
I do all my work except the recent trans rebuild. When you do your own work, you get it right and things will work.
Past weekend, I cleaned the evaporator in my 1992 Prizm/corolla by removing the blower fan. Upon inspection I saw about 60% of the evaporator core is clogged with dirt and what not. I sprayed water and blow the dirt and debris with compressed air. It is blowing very cold air and I get to use speed 2 now in this summer in West TX. Had I taken it to a shop, guess what, I'll be asked to replace even the compressor and $1000 job. Mine cost nothing except some nuisance to neighbors because the compressor was running.
Past weekend, I cleaned the evaporator in my 1992 Prizm/corolla by removing the blower fan. Upon inspection I saw about 60% of the evaporator core is clogged with dirt and what not. I sprayed water and blow the dirt and debris with compressed air. It is blowing very cold air and I get to use speed 2 now in this summer in West TX. Had I taken it to a shop, guess what, I'll be asked to replace even the compressor and $1000 job. Mine cost nothing except some nuisance to neighbors because the compressor was running.
shtbrwn86
SILVER Star
I DIY AC on older cars for sure. Here is what you need to understand:
1. If it's simply a leak - look at common places for dirt build up. If you don't see any - it might be one of evaporators.
2. Gauges useful for diagnostics, but in case of leak, I really don't use or care about what they show anymore.
3. Once leak fixed, you need to vacuum system and make sure vacuum stays. Easy enough. Use Nylog on connectors (o-rings)
4. Charge by WEIGHT. Don't look at gauges. There is different modes, temperature, altitude, etc. Don't bother. Just charge how much it should be. You know how much in a can, just eyeball last can, thats it!
5. Oil, Oil carried in a system, most of it in compressor and then it's spread out around. If you replace just a line - there is probably 1/4 oz oil in there - don't even worry about it. Because otherwise - you need to make sure you buy correct PAG or ester (whichever it is) weight oil. Too much oil is not good either.
So, as you see - no big deal. Leaks is easiest because all you do is find a leak, fix and vacuum/charge.
Only problem is - it's illegal to vent refrigerant to atmosphere. Shops have recovery machine. But if all your refrigerant already "lost" due to leak - you are OK
Watched Timmy the Toolman video and he mentioned emptying three of the 12oz cans into the system plus a little more "by feel". You also mentioned eyeballing the last can. The FSM says 37.03 +- 1.76. If I emptied three cans that's 36 oz. which is within the +- range. Is there a reason to try and get another couple ounces in there? You could get another 2.5 ounces if you wanted to... which leads to my next question. What do you do with the partially used can? Does it reseal itself when you take the tap piece off?
Yes save for later
I would not worry about those 2oz
Normally I'm a DIY guy but when it came to the AC install on my Jeep CJ7, I installed all of the equipment, connections, wiring, and hoses but then took it to a local very trusted shop. I'm glad I did. I had done the typical YT views and tool research but decided against it after getting quotes.
Several parts from the AC kit failed and they replaced them for free with what they had in their warehouse. I also had a goof that they fixed. They also didn't charge me for the 2 additional top-off / re-charge that it took after the leak. Total bill was around $140 and it blows very cold.
When the 100 was failing to cool, I took it to them again. Came back blowing colder than it ever had before.
Several parts from the AC kit failed and they replaced them for free with what they had in their warehouse. I also had a goof that they fixed. They also didn't charge me for the 2 additional top-off / re-charge that it took after the leak. Total bill was around $140 and it blows very cold.
When the 100 was failing to cool, I took it to them again. Came back blowing colder than it ever had before.
TexLexican
SILVER Star
is there an o ring kit out there?
I am pretty sure generic kit for asian cars will do. There is few sizes green o rings
I DIY'd my keys right over to Toyota service department. Just money, you'll make more.
- Thread starter
- #15
I keep telling my bank that when my mortgage payments are due, but they don't seem happy about it.
shtbrwn86
SILVER Star
I really want to DIY the AC recharge, but AC work has always seemed like a dark art to me. The reason I want do DIY is because I replaced the HP line in 2020 and had it evacuated and re-filled. It stopped working 10 months later (due to a leak). I took it to a shop and they said they ran a vacuum on it and couldn't find a leak and asked me if I wanted to refill it, so I said yes... It stopped working like 6 months later. I took it to another shop and told them, look, it keeps losing refrigerant and I've filled it twice now and can't find the leak with the UV dye that keeps getting added. They said the same thing "Can't find a leak and it holds vacuum, want us to fill it up?" Leaked out like 2 months later.
Bottom line is, I've spent like $700 on recharging this system. That's why I am just replacing everything but the rear evaporator. I also picked up 9 cans of R134A at Wal-Mart when I was in Idaho because you can't buy it in Washington State anymore. But at this point I am also considering just replacing all the components and then taking it to the shop to charge it up and sell the R134A on the black market here for insane profits! MUAHAHAHAHA
I am so bitter about AC work. I can't stand the industry. It's like pharma, or the NAR, mexifornia, thanks f ers.
DIY. if ten dollar cans of 134 don't convince you than nothing would. Look a the yield curve of R134.
I swear I'm moving contires. I'm that 70 year old man with the diesel merc getting pissed off, shopping at walmart, with dollar cans of 134 in the trunk,
dying of a heart attack because Folgers costs 20 dollars a pound.
re sealable cans, gtfo
DIY. if ten dollar cans of 134 don't convince you than nothing would. Look a the yield curve of R134.
I swear I'm moving contires. I'm that 70 year old man with the diesel merc getting pissed off, shopping at walmart, with dollar cans of 134 in the trunk,
dying of a heart attack because Folgers costs 20 dollars a pound.
re sealable cans, gtfo
TexLexican
SILVER Star
have you changes out the low and high Schrader valves?
I second this. I had a leak recently from my low side valve. The one that came out was stuck in the open position once pressure was removed. It had no spring tension left. With a bad valve the system will hold a vacuum and keep pressure with the manifold gauges attached but it will not last in real life use.
Rent the manifold gauges, pressurize the system with nitrogen or shop air (it's been open to the elements plenty...), then spray soapy water on the valves and all suspect areas of line. The leak is there somewhere! Pressurizing allows you to eliminate o rings that seal under vacuum but not positive pressure as well as giving a chance to remove the gauges and check the valves.
shtbrwn86
SILVER Star
I replaced the high-pressure line (very visible leak) when I first bought the rig. That's why it was evacuated and recharged the first time. I didn't replace the schrader valve on the low side though. I guess I would have thought if it was a big enough leak to run out that quickly it would have been obvious looking at the valve. I also did an AC sniffer test although the engine was off, so it wasn't under as much pressure as if it was running? Maybe I should also replace the low side soft-line while I am at it. I could replace the valve, but the crimped part of the line was what leaked on the high side.
That being said, there's some pretty obvious leaked oil/dye on the condenser, and the sniffer squawks on the evaporator, so I am pretty sure those were the big leaks. Thanks for pointing that out. I will do the low side too since it's all empty now anyway.
