Help - Can I do this myself

[BrettS]

I have a confession to make... I don't actually have an Explorer, but I happened to find this message board in one of my google searches. You guys seem to be quite knowledgable and friendly, so I'm hoping that you'll be able to help me anyway.

What I do have is a 98 Jeep Cherokee with AC problems. For the past several years I've had a slow leak in the AC system. Every spring I'd need to add a can of refrigerant to the system, and for the past year or two I've been needing to add at least one more before the end of the summer. Even worse, a few months ago the bearings on the AC compressor clutch started to go and more and more frequently it makes a horrible grinding noise as the car runs. It had been happening fairly infrequently, but lately it's been happening often enough that I need to do something pretty soon.

After doing quite a bit of research on the internet I've decided that replacing the compressor is something that I can do myself. I've never done any AC work before, but I've done other work on my cars and my father-in-law is a shadetree mechanic and is only a phone call away if I get myself into a mess.

Everything I've read says that the accumulator and orifice tube should be replaced when the compressor is replaced and that doesn't look too difficult either, so I'm planning to do that. It also looks like it's recommended to replace, or at least flush the condenser as well.

Here are my questions -

I don't believe I have the equipment the flush the system. Can I get away without flushing it, or am I just asking for trouble? Is there something reasonably inexpensive I can buy to flush the system for me?

If I don't flush it, am I better off just replacing the condenser? Even if I do flush the system, should I replace the condenser? Should I just replace it anyway in light of the slow leak I've been having on the chance that the leak may be in the condenser?

I don't have the equipment to draw a vacuum, so after I replace everything I'm planning on taking it to a mechanic to evacuate the system, leak test it, and recharge it. Any thoughts on what would be a reasonable amount to pay for this service?

Finally, anything else that I'm overlooking or should also replace? Any other tips or suggestions?

Thanks much,
Brett

 

[manaen]

there are many threads on here about this, browse through the AC posts, if you still have questions then post them. AC systems are pretty basic in operation and can be cleaned/flushed by yourself. You may want to talk to your AC service person before doing it, they may want to perform the maintenance in house, otherwise they may not be able to guarantee the work

finding a leak in the AC system is a simple procedure, there are also leak detector dyes that can make it even easier. I wouldn't replace the condenser just to replace it, they can be cleaned, unless there is a leak in it somewhere.

 

[BrettS]

Thanks for the reply. I've been doing quite a bit more research today and I'm feeling much more comfortable about this. I'm still a little worried about the condenser - there's definitely a damaged spot that looks like it was hit with a rock or something, but I think it's just the fins that got damaged and I'm hoping it doesn't leak.

For now, though, I'm planning to replace the compressor, the accumulator, and the orifice. Unfortunately on the Jeep the orifice tube is permenantly installed in the liquid line, so replacing the orifice means replacing the liquid line, which adds to the cost, but it doesn't look like it'll be too bad.

From what I've read I'm thinking that I really should flush what's left in the system, so I'm planning on doing that. Is something like this: http://www.jcwhitney.com/autoparts/...02877/p-2002877/N-111+10201+600002283/c-10101 good for flushing, or is there something better that I should use? Can I flush the evaporator and the condenser in place or will I need to remove them to flush?

Thanks again,
Brett

 

[BrettS]

The more I think about it, the more I'm worried about the leak in the system. I'd hate to go through all this only to discover that there is still a leak. Do you think it's worth trying to diagnose the leak before I start this work, so I can be sure to replace whatever is leaking, or do you think I have a good chance of fixing the leak by replacing the parts I do plan to replace?

From what I've read here, the UV dye's don't seem to be too reliable, so I'm probably looking at asking an A/C tech do it, or trying to purchase a leak detector... I'm assuming that either method would be at least $80 or $100... unless I can rent or borrow one from an auto parts store.

Thanks,
Brett

 

[CDW6212R]

For a leak have a good AC shop check that, there is a very big difference between detectors. Most cheap units will not find a lot of leaks. Call around for a good price for checking for a leak. If you can find the leaks before the big work, you can know that you got everything.

I prefer to let my AC guys do my vehicles. I do the R&R work, and let them do the vacuum and charging stuff. If you have a good working AC, the freon hasn't reached too low of a level, the R&R work can be done, and no other parts need to be changed. The dryer is the most sensitive part to atmosphere(moisture). That cannot be allowed to absorb air for very long, it must be installed immediately. The old one the same, you can't do the R&R work, and a day or so later go to the AC shop, the dryer would have to be replaced then.

FYI, most AC systems have quick connections, with o-rings inside of them. Those are a main source of leaks on a lot of vehicles. If you have any of those, and keep the vehicle for a while, replace those o-rings, and install aftermarket locks there. The OEM locks don't stop vibration, the aftermarket type do. Good luck,

 

[rookieshooter]

With out a doght check for leaks. Leaks can be hard to find also even if you do have a leak detector. Now a larger leak is easy but a tiny one can be hard. Mechanic could after evacuating your system, pressurize it with nitrogen and leave his gauges on and check in a few hours or even the next day.

 

[manaen]

And if your only topping it off twice a year that is a very, very slow leak

 

[BrettS]

Well... in case anyone is wondering about the status of my own mini saga, here is an update.

I've ordered a compressor, an accumulator, and a liquid line (which is the only way to get the orifice tube). I also ordered 6 cans of r134a, a quart of PAG oil, a flush kit, an AC line disconnect tool, a manifold/gauges set, and a vacuum pump. All of this should be here by Friday, so hopefully I'll have a functional AC after a bit of work on Saturday.

Originally I was planning to have someone evacuate and recharge the AC for me, but after calling around the cheapest price I could find was $130... I was also quoted a bit over $100 to have someone search for the leak (since they'd have to recharge the system first).

I was able to get the manifold/gauges and pump for a bit under $150, so I figure I'll just go ahead and hope the leak is fixed with the work I do. If it still leaks, then I'll try to get it diagnosed at that point (it should be cheaper because it'll already have a charge), and if I need to do more work, then I can fill it again myself and I should come out ahead in the end. Plus I'll have the pump and gauges if I need to do any other work in the future.

Thanks again for all your help,
Brett

 

[Blee1099]

Don't forget about a sniffer.. Harbor freight sells a sniffer for around $100, http://www.harborfreightusa.com/usa/itemdisplay/displayItem.do?itemid=92514. Definately one of the best tools i've bought recently for leak detection compared to the dye kits. The dye can be messy at times and not to mention there's been an argument whether or not the R134a molecules are smaller or bigger than the dye molecules.

 

[BrettS]

Just a quick update and a few questions. I got all of my parts Thursday, but unfortunately the oil, gauges, and vacuum pump that were supposed to arrive on Friday were delayed in shipping, and I won't get them until Monday. I decided to go ahead and do what I could today, planning to evacuate and charge the system on Monday once I got those tools.

I first noticed that the valve on the low pressure side seemed to be leaking. As soon as I took off the plastic cap I could hear refrigerant leaking out. I'm not sure if that was my leaking problem all along or if that was something new. I hadn't tried to recharge the system since last summer and I don't recall it leaking like this then. The valve is on a hose that's part of an assembly that includes both the low pressure hose and the high pressure hose, so I ordered a new assembly. Unfortunately I'll have to wait until Tuesday for that to get here.

I decided to continue going as far as I could today, so I disassembled everything (those high pressure lines were a pain... even with the tool). I took out the old accumulator, compressor, and all the lines. I flushed the compresser and evaporator - there didn't seem to be any dark gunk in there, so I figure that's a pretty good sign.

I installed the new compressor, but didn't connect it yet because I won't have that hose assembly until Tuesday. I left the cover on it. I replaced the liquid line (which includes the new orifice tube) between the condenser and evaporator. I used all new green O-rings. I didn't install the accumulator yet, because I didn't want to expose it to any moisture. I figure I'll install that Tuesday shortly before I evacuate and recharge the system.

Here are my questions: The compressor said that it comes with no oil, so obviously I'll need to add oil to the compressor. Since I flushed the evaporator and condenser and replaced everything else, I'm assuming that there's no oil in the system now. How much should I add and where should I add it? I seem to recall someone suggesting that some should be added to the compressor, some to the condenser and some to the evaporator.

Also, when I finish assembling everything, how much refrigerant should I add? Should I go by the gauges or just put in a certain amount?

Thanks again for all your help,
Brett

 

[Glacier991]

Use the amont of refrigerant that the sticker says you need.. I think it will be 24 Oz.

 

[BrettS]

Use the amont of refrigerant that the sticker says you need.. I think it will be 24 Oz.

Hey... look at that... there's a nice little label that tells me how much refrigerant to add. The sticker says 1.25lb, which, if I calculated correctly, should be 20oz. Unfortunately I'm getting 12oz bottles, so I'll have to try to leave 4oz in one of the bottles, but hopefully I can get pretty close.

The sticker didn't seem to say anything about how much oil to add. Do you guys have any suggestions about that?

Thanks again,
Brett

 

[gsmaclean]

Don't forget about a sniffer.. Harbor freight sells a sniffer for around $100, http://www.harborfreightusa.com/usa/itemdisplay/displayItem.do?itemid=92514. Definately one of the best tools i've bought recently for leak detection compared to the dye kits. The dye can be messy at times and not to mention there's been an argument whether or not the R134a molecules are smaller or bigger than the dye molecules.

When I still had a leak in my 94 (it would leak from a full charge to nothing in about two days), I ran two whole cans of dye through it and never saw a speck of it leaking out anywhere. At least in my case, the dye was utterly useless.

 

[Glacier991]

As for oil, the first stickie at the top of this forum will answer your Q... add about 4 oz to the compressor and rotate it by hand to distribute... the balance add to the condesnor and accumulator.

 

[BrettS]

Well... I'm happy to say that everything is finally working now. My hose assembly took longer than I expected to get here, but it finally arrived and I was able to add the oil and finish reassembling the system. I hooked up the vacuum pump and let it run for an hour, then charged it with about 20OZ of r134a. It's blowing nice cold air right now and I'm very happy.

Unfortunately I still don't have a leak detector, so I'm hoping that it will still have a charge tomorrow morning... and next week... and next month... and next year, but we'll see.

Thanks again for all of your advice... with your help I probably saved at least $300 and still got a gauge/manifold set and a vacuum pump.

Brett