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View Full Version : Looking to buy R134a Manifold Gauge Set - input?



paulkeith
05-03-2010, 11:24 PM
Like the title says. A/C in the 5.9 hasn't worked since I've owned it and now that the humid happened its time to get on a fix.....but in general I wanted to add a gauge set to the tool arsenal anyway. I'm thinking of also buying a vacuum pump while I'm at it.

Has anyone purchased a set on their own? Thoughts? Input? Lessons learned?

Thanks in advance.

Paul

leeanderthal
05-03-2010, 11:46 PM
I work at a dealership, the ac machine is nice but pricey. I also work side jobs and the equipment is old as hell and still works, sorry don't know much about who made them. But one thing to think about is a scale, to put the proper amount back in.

rccolacc
05-04-2010, 01:08 PM
I got a set a few years ago. I was in your same situation and just went ahead and bought the tools rather than take the Jeep. For the amount of work I've done on my vehicles and friend's cars, they've more than paid for themselves.
I'll have to go look at the brand I got, but I think it was yellow jackets or something. I bought it at a Johnstone A/C Supply. Paid $150 I think. I got a good vac pump machine ($300) and an electronic freon sniffer ($300). Yes it's an expensive initial cost, but you really can't do any A/C repair without the vac pump, and the sniffer is nice to find leaks real easy.
I've worked on A/C's on probably about 20 cars in the past 5 years. It's all shade tree type stuff, and not professional, but here's what I've learned. FWIW- I've never used a freon scale. I buy all my freon in the little 12oz cans and I've never tried to recover the old stuff in the system. Most systems are only 24-36ozs, so breaking the system when you're changing out a compressor or something only is going to cost you $20 in freon. Most of the time when you're trying to diagnose the "why isn't it cooling" problem, the system is low on pressure anyway, so there's not much to recover if you wanted to.
Are you familiar with working on A/Cs in cars? It's not really that hard if you've never done it. The initial expense of the tools is the hard part.
-RC

rccolacc
05-04-2010, 01:22 PM
I work at a dealership, the ac machine is nice but pricey. I also work side jobs and the equipment is old as hell and still works, sorry don't know much about who made them. But one thing to think about is a scale, to put the proper amount back in.

I've always gone by the high-side pressure and the vent temperatures. If you look in the engine compartment, there's usually a sticker with how much the system holds somewhere around. I always shoot for ~300psi on the high side, and 40-50F on the vent temperature. This is usually with ~80F ambient temp. Most of the time it ends up being slightly more ozs than what's on the sticker. Probably not the most professional thing, but it works.
-RC

ATL ZJ
05-04-2010, 01:26 PM
Paul, you should talk to bailey about this if you are really serious about doing it. He had major A/C problems in his FJ80 and took pains to do it right, finding all the pitfalls and booby traps along the way. To this day he gets really charged up about A/C...

my apologies for the awful pun.

paulkeith
05-04-2010, 05:56 PM
hah, nice.

I'll think about it really hard and maybe that'll will him to this thread.

Thanks to all for the responses thus far.

Just a visit to the A/C shops around here will run you like $150, so that'd already get me most of the way to a set of gauges and an OK vac pump.

I've worked on them to the extent of checking pressures and topping off with filler cans, disassembling discharged systems, etc, but never troubleshot, fixed, filled & run a system from the ground up....

My compressor is engaging but quickly disengaging, so I'm assuming it is low on refrigerant, but I'm also assuming this means there is a leak somewhere. Its got a dye sticker under the hood, but how does one use said dye? UV light?

Jeeptech01
05-04-2010, 08:00 PM
I've never tried to recover the old stuff in the system. Most systems are only 24-36ozs, so breaking the system when you're changing out a compressor or something only is going to cost you $20 in freon.
-RC

So you are saying you release harmful gasses into the atmosphere that destroy the enviornment and ruin the planet for those to come? But it is ok cause its only a little bit? How many other idiots like you are out there thinking the same thing? Then is it a big deal? There is a large fine imposed on those who dont properly reclaim freon of any kind also so if ruining the enviornment doesnt bother you maybe being flat broke will.

Paul alot of shops have a machine capable of recovering refrigerant and usually charge less than $50 to recover a charged system. You could try some of the tire "chain" stores. As for learning the system it is very basic once you understand it and if you do you can def make some good money from it. I say invest in a good pump and dont go crazy on the gauges since they really dont have to be much fancier than a spigot with a pressure gauge.

paulkeith
05-04-2010, 10:11 PM
Does anyone have a vendor for these parts that they've dealt with? The johnstone website is pretty weak. Amazon actually seems to have a pretty large selection?

Cam...next time you talk to bailey tell him to drop in on this thread. I dont have his number and I figure PMing him won't do much good if he isn't on here a ton...

leeanderthal
05-04-2010, 10:16 PM
Most of the parts stores around me have tool reps. They can usually find stuff like fairly cheap. I just picked up a frreon sniffer last week for a 150 bucks. Just a thought.

rccolacc
05-05-2010, 12:53 PM
So you are saying you release harmful gasses into the atmosphere that destroy the enviornment and ruin the planet for those to come? But it is ok cause its only a little bit? How many other idiots like you are out there thinking the same thing? Then is it a big deal? There is a large fine imposed on those who dont properly reclaim freon of any kind also so if ruining the enviornment doesnt bother you maybe being flat broke will.


Come on man. Calm down a little. I'm not an idiot, and I've never relieved a full system of freon into the air. R-134 has HFCs in it, which are actually less harmful than the CFCs in R-12. If I did A/C systems as a business, then yeah I'd get a tank to reclaim, but since I only work on a few a year, and maybe MAYBE break a system once a year to repair something, then I think that releasing a few ounces of 134 into the air is ok. Heck-- if you take the A/C test to get your license, they even tell you it's ok to refill a system if you know it has a leak. How is that different than purposely leaking it? It's not.
I respect the environment, but I'm also realistic.

About Johnstone-- yeah they're hard to buy from unless you've got a store by you. They like to deal with A/C companies and large businesses, so I guess you're best bet is to try somewhere else unless there's a store by you.
-RC

Jeeptech01
05-05-2010, 10:15 PM
Admittedly some leakage unavoidable but that is not how you came across. IIRC refilling a leaking system more than twice a year is frowned upon in the cert test. Scientists are also figuring out that r-134a is not quite as safe as they originally thought. I appologize for coming across so harshly but many people read these posts and take them very literally. Tree huggers dont need any more ammo than they already have or we will be saying goodbye to trails like Tellico more often. I was pretty upset about that since I always wanted to go so I guess your post came at a pretty inopportune time.

CruisinGA
05-06-2010, 08:00 AM
Paul- I'd post up my experience, but I've got my last final today. Shoot me a PM with your number and I'll give you a call later today after my last final....ever. :D

paulkeith
05-06-2010, 08:50 AM
Over/under on said phone call being coherent? :D

PM sent

paulkeith
05-06-2010, 10:46 PM
Well, felt ambitious leaving work today and decided another $130 on the credit card wouldn't kill anyone.

Went to advance, and bought: a manifold gauge set w/ 72" lines, can adapter, 2 cans R-134a, UV pen light and UV filter glasses.

Came home, started reading, and hooked everything up. Compressor wouldn't engage so I jumpered the low pressure cutoff switch. Compressor engaged and I was reading about 10psi Lo 75 psi Hi.

Started letting one can into the system, let it fill for about 10 minutes. Ended up at 40/225, which was on the low side of the book's range for the ambient temp. Air in the cab is pretty cold. Not as good as my truck's A/C, but Ford usually kicks pretty serious ass at A/C and heat. I'd say its now as good as my 4.0 a/c ever was.

The refrigerant had been previously UV dyed, and I confirmed this when a tiny bit shot out as i connected the hi-side fitting. Bright green. So, using the pen light and glasses I scoped all the connections and what i could see of the condenser and found no signs of leakage.

We'll see how long it holds the charge. There are signs that lead me to believe the accumulator has been replaced...it looks "new", the lines are routed "wrong" compared to my buddy's 5.2, and it was loose in the bracket. *MAYBE* they just didn't charge it right when the replaced that, or the more likely option is that there's a leak, and its probably in the evaporator.

Talked to bailey on the phone and we came to the conclusion that the pressures are good, but I might want to add some oil at a ratio matching the amount of refrigerant I put in. I'll probably do that tomorrow.

Anyway, $130 later and my A/C works. For now. I'm skeptical....A/C fixes are never this easy.

Also, what pressures should I see when the compressor is not engaged?

leeanderthal
05-06-2010, 10:49 PM
Both high side and low side should be about the same. May take a sec to get there.

paulkeith
05-06-2010, 11:05 PM
They're equalizing, wondering what they should equalize at. I'm sitting at close to 100 PSI, it was probably ~85F ambient in my garage. Seems like from pressure/temp charts I might want to be in the 85-90psi region?

I realized after reading more I did the tests at idle and should've done them around 1200-1500RPM. Perhaps I am overcharged now.

rccolacc
05-06-2010, 11:56 PM
Glad your fix was easy. Most of the time they are. FWIW, every summer I add a can to my ZJ. I have a slight leak somewhere and it leaks out over the winter. I'm sure yours is prob the same way.

Don't worry about what the pressures are when everything's off. It really doesn't matter. Whether the system is full or not is strictly from the low and high side pressures with the compressor running and the A/C on full cool and fan on high.

I always do A/C charges and checks with the engine at idle. Sometimes I drive around a little bit and then check the pressures, but really it should be read at idle. Running the engine up will change the high side pressure (run it higher) and give you a false reading.

I don't know if I'd add the oil if I were you. The oil is evenly mixed with the freon and throughout the system when the A/C is new. When the freon leaks out, it mostly leaves the oil behind in the system. You're really only supposed to add more oil when you replace a component of the system (like the accumulator or the compressor). Since you didn't, I wouldn't put any more oil in, and just assume that whoever replaced the accumulator on yours added the correct amount of oil when they did it. Over filling the system with oil will cause it not to cool as well.

If I were you, I'd get a cheap thermometer (like a food thermo) for the vent to measure vent temps, just to see where you are with the job. It sounds like you're there though. I'd add a little more freon since you're on the low side of the chart, but call it good man.

Congrats on the easy fix. Hope it goes well for you.
-RC

rccolacc
05-07-2010, 12:01 AM
One more thing about the over-filling. I think I read somewhere that most systems have a blow-off valve somewhere in the compressor and it's usually around 350+psi. As long as you're not there, you're not over filled. If you are over filled, then technically it will blow it off when the pressure gets that high (and hopefully not blow a hole in the hose at the same time, lol).
-RC

Jeeptech01
05-10-2010, 10:06 AM
The blow off valve is designed to pop in the case that the system has a restriction or that the condenser fan is inop causing the system to overheat. It is more of a safety feature. If you are overcharged you will have to remove some freon from the system. For max efficiency from your system be sure your condenser is clean and free of debris, your fan(s) are working properly, and your evap air intake is clean and free of debris. Also make sure your evap case drain isnt clogged since it is very common on the ZJ.

paulkeith
05-10-2010, 10:38 AM
It was still tripping the low pressure switch under higher RPM. I hooked the gauges back up and saw it was dropping to about 25psi on the low side under RPM. I added the rest of the 1st can, and now have about 45/230 at 1500RPM. A/C works at all speeds and is pumping out a vent temp of 40F in 85F ambient. The compressor however is not as quiet as I would like however........ and I fear my victory may be short lived. TBD.

spykosshow
05-10-2010, 12:46 PM
I just noticed this post, sorry. I have a buddy that charges my Dodge's AC every year and he got his vacuum pump and gauge set from 4x4ac.com (jeepair.com).

Jeeptech01
05-10-2010, 02:23 PM
You could try adding some oil. If you have an evaporator leak they tend to hemmorage oil a bit. The oil may quiet it down. Some of the cans or r134a have oil in them just be sure not to get any stop leak or you will have trouble getting anyone to service your system since it clogs recovery machines.