Prius C AC condenser replace and recarge

Fair enough - that wasn't clear to me from your summary of the costs, perhaps my fault for not reading carefully enough (a bad habit of mine).

I think it's a mistake to conflate repair costs with the purchase cost of the car. Even cheap cars can need expensive repairs.

I've learned to budget for repairs. My habit is to buy a car and run it into the ground, so I put aside some money every month for repairs, even in the early years when the maintenance cost is low. Then when something happens and I get a repair bill I don't sweat it because I already have the money set aside. When the car is at the end of its useful life I take whatever money is left in my repair fund and add it to my "next car fund" to buy the next car.

 

Glad to hear your car was fixed successfully! I'm hoping mine will be just as easy.

 

Warranty is for defects in the vehicle. Why on earth would you expect the dealer to warranty the AC condenser when it was hit by a rock? That has nothing to do with a defect in the car. It has nothing to do with Toyota. You're "$1000 repair in the first year" was simple bad luck. Like getting hit by another car at an intersection. Would you expect them to warranty that?

The low-side and high side pressures have nothing to do with the system being "full." The only way to know how much refrigerant is in a system is to remove and weigh it. Then you vacuum it down, and charge the specified amount. The dealer techs know this, but more on that later.

Here's a side effect of your grossly undercharged system: The ND11 oil is carried through the system in the refrigerant. This is critical to lubrication of components throughout the system, including the compressor. Evaporated refrigerant entering the compressor is also critical in cooling the compressor. Keep driving it with a low refrigerant charge, and there's a good chance the compressor will prematurely fail. That's a tick over $1,500. The good news is that with a burned up compressor, you also get to replace the evaporator, condenser, remove and flush all the lines, and on and on. Hopefully, the electrical short that's bound to happen (refrigerant cools the electric motor, too), doesn't take out the inverter, too.

Starting to see why the dealer charges good money for these tasks you labeled as simple and cheap. You say it was cheap and easy, but you did it wrong, and you're heading down the road to a very expensive repair. The dealer charges "big" money because they have to buy expensive equipment to do the job correctly, and they have to pay people with the education and knowledge to do the job correctly.

 

Today I decided to do the condenser install because I don't work until 2. Here's my photos from the process. The process is very easy. It goes in from the top. Mostly trim panel clips and several 10mm bolts.



You can see how much damage my OEM condenser has taken over the last 3 years. It's very unprotected. On the right is the new Sunbelt one from Amazon. The new condenser did indeed include the desiccant bag in the built-in receiver/dryer.

Put 1.5oz of oil into my condenser, and lubricated all involved o-rings with ND-11 oil. Interestingly, many A/C techs recommend mineral oil to lubricate the o-rings on non-hybrid systems that use PAG. I don't want any contamination at all so ND-11 only for me.



Tomorrow I'll be doing the vacuum and charging.

Matt H - I wouldn't expect a low charge to damage the compressor. The evaporator will freeze up due to low pressure first. The low pressure cutoff switch will shutdown the system if the pressure gets really low. The correct way to get the car running with the proper amount is comparison of the ambient temperature with a pressure chart for R-134a. If they system takes a different amount - it takes a different amount. Slightly low pressure can actually result in better cooling performance, but at the risk of freezing up part or all of the evaporator in certain situations. It's just basic A/C knowledge.

Lower pressure is far better than overcharging which COULD result in damage to the system - but again - there's a high-pressure switch that will shut the compressor off if this happens as well. The damage resulting from high pressure will probably manifest itself as leaks from weak points in the system.

I wouldn't expect the failure mode of a seized compressor to lead to an electrical short. Toyota engineers test every component for failure modes, since a short circuit could potentially cause a fire, there are probably engineered protection mechanisms such as fusible links to protect the A/C inverter and the main inverter from damage.

 

In addition to owning a hybrid specialist repair shop in a country where almost half the cars on the road are hybrids, I also have a full-time day job - ME, specifically HVAC. Also 609 certified, 608 Universal certified. ASE Master, L1, L3, member SAE, etc.

The evaporator won't freeze up, as the evap. temperature is monitored. The danger in having low refrigerant charge is, as I stated above, that the oil migrates through the system in the refrigerant. Less refrigerant means less oil flow. Refrigerant also cools the compressor, and less refrigerant means less cooling (see more below).

Refrigerant leaving the evaporator is also cooling the compressor. In a Toyota hybrid this is super-critical, as it has another job, which is cooling the electric motor part of the compressor (refrigerant flows through the motor). Less refrigerant (this guy put in half), is less cooling medium. An evaporator discharge temperature of 30°F can happen with a correct charge, or a low charge. The difference is that there is less refrigerant. The delta-T is higher when measured at the compressor inlet with a low charge, but more critical is the volume. Think of a hot-wire MAF with an ambient temperature of 30°F. At idle, or WOT at 5,000 rpm, the temperature measured in the MAF is the same, but the hot wire doesn't cool as much, as there's less volume flowing through it. There is less cooling medium (R134a) to cool the components. In some heavy-duty non-automotive systems with electric compressors, we run compressor motor temperature probes, compressor discharge temperature probes, etc. When the compressor motor temperature reaches a set point, we open a LLSV, which leads to an expansion valve, and injects liquid refrigerant into the compressor inlet to cool the compressor. We also use stepper-motor E-TXV's for precise refrigerant metering, as it's a delicate balance between cooling the compressor, and slugging it with too much liquid.

You can go substantially under and over charge without seeing a difference in pressures that will lead to low or high pressure shut down. You can not determine how much refrigerant is in the system by pressures. If you have your MACS cert, you should know this. The ONLY way is to charge the system with the correct amount of refrigerant. The design of the system determines how much refrigerant it gets.

I've replaced plenty of Toyota AC compressor's for mechanical failure, and electrical failure. So far, all have been from someone who doesn't know what they're doing... Phase to phase short, or phase to ground short from winding insulation degradation from heat, the wrong oil contamination, etc. The ECU will disable the system when it senses any kind of short, over-current, undercurrent, etc. Exactly the same way it does when is senses this in the HSD. However, sometimes it takes out the inverter, too. A mechanical failure in the compressor (lack of oil) will send metal debris through the motor, and sometimes kills that part of the compressor, too. As the compressor wears slowly from lack of lubrication, this debris can kill the motor before the compressor stops compressing.

Oil charge: Critical.
Refrigerant charge: Critical.

There are no fusible links in the HV system. Leads go directly from the inverter to the different motors. There is sensing circuitry to tell the ECU's if there is a problem somewhere. It's not often that a compressor failure takes out the inverter, but it does happen. They don't "blow up," or catch on fire. It's a simple matter of a cap or IGBT being damaged to a point where it no longer functions within design parameters, and will set a code/shut down until it's replaced.

Bottom line: There's a correct way to do it. It's spelled out in black and white int he SI. Not doing it correctly in a Toyota AC system runs a large risk of a very big repair bill.


Hope that helps.

 

Forgive my ignorance, but wouldn't a leak also cause low pressure of the coolant? And aren't leaks a rather commonplace problem? So wouldn't the system be designed to shut itself off before the pressure dropped to the point where it could cause damage or, certainly, safety concerns?

 

Great information! Thanks for the reply.

I actively try to repair everything that I own myself. From the clothes dryer, to the deck, each car, computers, old software. It's about self-sufficiency. It's about the sense of accomplishment when it works again. It's about not burdening others with problems I could have fixed. The DIY spirit is why I joined these forums. Sharing knowledge of what works and what doesn't is an awesome thing.

But it's mainly about something else: the technicians here generally don't have the same work ethic that you have in your country. They are only interested in getting cars out. Only interested in making 100 flat rate hours a week. Perhaps they'll use power tools to disassemble the car, loose a few bolts. Get a 3 hour job done in 45 minutes. Perhaps they'll pull a vacuum for only 5 minutes because who's gonna know. Whack em for a coolant flush. Whack em for a cabin filter. Get paid. I would like to think that a dealership would have the best, and most by-the-book employees out there. There are lots of brilliant dealer techs, but there are far more that don't care. I've worked with those guys. At my dealer- I was the only one who insisted on being honest. And at the end of the week- I made the least hours. The ethical questions are actually one of the main reasons I left the industry.

 

Have the vacuum pump running now on brand new pump oil. I bought a new set of manifold gauges and hoses that are going to be hybrid only - they will never be used on my other cars.


The altitude is things interesting. I'm at 9005ft altitude. My atmospheric pressure here is 10.5psi vs the 14.7 at sea level. Instead of 29.9in/hg of vacuum at sea level, I'm looking for 21.4in/hg of vacuum at this altitude which will be the maximum I can attain.

 

Charging was successful. Opening the low side valve, refrigerant flowed in right away, and the compressor clicked on and started taking more in. It took about half the can in less than 5 minutes. Total - my car took an entire 12oz can, plus just slightly over 2oz of the second one.

The car's capacity is 420g +- 50g according to the underhood label.
That's equivalent to 14.8oz +- 1.7oz

Mine is probably slightly under, but still within spec - but the pressures look perfect, and the vent outlet temperature is somewhere around 36°F.

It took a LONG TIME to get it to take the full amount. I charged on the low side with the A/C on LO auto. I took the opportunity to clean all the windows while I was waiting. The charge process took just over an hour.

 

Finally got some pics of the mesh behind the grill:





Lol, it's good at stopping leaves. You can see that it will stop or at least slow down larger rocks that fit through the regular grill openings.

 

My pressures did look pretty good very quickly, and the AC sounded and acted normal after less than 5 minutes. My high side pressure was lower than the expected level though, so I kept going. Since I'm at high altitude, I wasn't quite sure if I could trust charging by pressure alone, so I waited until the correct weight was charged, while monitoring the pressures.

When I worked in the shop and had access to the fancy AC machines, I'd usually charge liquid in the high side with the car off, mainly because it was faster. Those machines have big tanks and very accurate scales. Since I'm working on my own car in a driveway, I figured a longer low side gas charge would be better out of my little cans.

xliderider- that looks great- that's how it should be from the factory! I was behind a gravel truck yesterday and I was really hoping my new condenser wouldn't get hit!

 

I went with black fiberglass "pet resistant" window screen. It's extremely subtle, and you can barely see it even a couple of feet away.


Took the bumper off. It's pretty easy - clips on the top, many 10mm bolts on the bottom, and the clips on either end.

Here's how I attached the mesh. Just zipties. I drilled holes in places that won't be visible from the outside for some of the zipties. I expect that this mesh will take many hits and will probably have to be replaced after a few years..

 

The mesh is very fine though. It will prevent air from moving freely through the grill openings. At least you don't live in a hot climate like desert or hot and humid weather.

 

I'll be keeping an eye on the temperature with my scangauge to see how much this affects my cooling performance.

 

Did it affected the cooling performance of your Prius C by any means?

 

Hey there! Not sure if you'll see this because it was so long ago, but what did you do to remove the condenser? Did you have to remove the entire front bumper? About to do this job myself, as the dealer told me I had a small leak in my condenser and wanted 1100$ for the job. No thanks!!