Afternoon, all.

I'm not from these parts, I have an SC300 and a GS400.

My mother however has a 2003 SC430. The ac totally died from one day to the next. I am entrusted to fix this as I am a part time wrencher and ASE cert. Master tech.

The issue I am having is that I find it VERY odd the ac is dead on this car with such low mileage.

So my question is to anyone that has had, or heard, of any ac issues, what was it and what was the fix? I'm trying to nail down any pattern failures on these cars before I go ripping apart the dash or replacing compressors.

Any known issues with this?

Vid of manifold gauges or car in question: https://www.dropbox.com/s/vouiu9vjpm...2010.16.18.mp4

Thanks, all!

 

OK I have a long story bout my 02 when it had about 30k miles. Worked fine one day then nothing the next and my gauges looked similar to yours from what I remember. So short story is take the compressor off and on the bottom not the back side, there is a Manual Freon Control Valve( some are electronic though) that is held on with a "ring clip". The actual name of it- I don't have at the moment but Orielly's had one for $50. After I spent much more $ than 50 dollars chasing this, the valve was my problem and has worked perfect since.

 

Thanks for the heads up.

On the bottom side of the compressor is only the thermal protector. If this was bad or tripped, the ac clutch would not engage and your manifold readings would be the same as when the ac was off (because it will not engage).

On this car tho the protector is bolted in with a bolt. And as far as I can tell, this car does not use the electronic control valve, that started on later model cars I think after 2005.

So anyway if you are remembering correctly and this manual valve does exist, can you perhaps get me a part number, or any more info? I checked on the O'Reilly site and the Lexus part catalogs and I can't find any part that matches what you describe.

Thanks!

I'd love for this issue to be as simple as a control valve and not be something serious like the expansion valve which requires gutting the interior completely. Ugh...

 

I know what you are talking about (thermal protector). I think that is on the front of the compressor. The control valve is on the bottom\side\back.

I also changed the Expansion Valve before the Control Valve and that was easy. Right above the feet on the drivers side, no problem to get to that and was not my problem. I will go outside and see if I can get you a part number on the controller.

 

The expansion valve can be done without removing the ac unit? The service manual shows removing basically everything but the dash pad. Steering wheel, cluster, center console, coolant, the works.

Is this another one of those times where the service manual totally gets it wrong, again? I've seen manual shortcuts but if the expansion valve can be changed right there without removing the entire front half of the interior that's great news.

Tonight I'll see if I can stop by my mom's and have another look at the compressor. While I'm there I'll take a peek up at the expansion valve.

Does the replacing the control valve require removal of the refrigerant charge?

Thanks again, man.

 

Yes the Expansion Valve is just above your feet on Drivers side. I think I removed the drivers seat to get at it but was simple. If you are going to replace that (I would try the Valve on the compressor first) make sure you replace the o- rings and oil the o-rings with proper oil, I think is PAG 45 not sure.

And yes the Freon needs to be removed. If the compressor was working fine before and making no noise, pick a day to drain and open the system that has low humidity. But either way, cap the open hoses with some kind of tape and try not to keep the system open very long or you will have to replace the dryer.

Pull vacuum for a couple hours after reassembly so you can verify no leak and remove some moisture. You may know this already.

 

Thanks again, man.

I'm going to take a closer look at her compressor tonight if possible to try and locate this valve. I would very much like to give this a shot first.

Much appreciated.

I was doing some investigation online and have found certain 7SB16C compressors to have this valve while others do not.



I will look harder at my mom's car tonight to see if I can locate it.

Thanks again!

 

That is the valve.

 

Okay I had another look at the car today. I searched the compressor up and down and I don't see where this valve could go. It's smooth all over except for where the two lines connect.

Is it between the compressor and engine to the point that it has to be removed to even just see it?

Also I don't see anywhere any applications or part numbers for this car and this part. Hahaha it's like some force doesn't want to me to find it.

Lastly, just to make sure, we are talking an SC430 here, right? (I know, I know, heh)

So yea if you have any part numbers, pics, anymore details, that would be awesome cuz I could really use the help on this one.

I checked up on the driver side dash, and yea the expansion valve is right there all by itself... sweet. Just in case I have to change that, which an ac specialist suggested might be my issue. And its actually pretty cheap. So we have some good news somewhere finally haha.

Thanks again...

 

There should be a tag on it that says "7sb16c" . If so, then that valve is there somewhere..

 

good luck bro, thanks for sharing!

 

So are these scroll-type compressors? and is that a scroll control valve on the compressor? Ford had/has a lot of problems with scroll control valves that stick, and you can't buy the valve by itself through normal channels - they want to change the compressor for you.

As others have said, if you are opening the system you really should have the equipment to pull the system into the needed vacuum or the moisture that enters even on a low-humidity day will freeze and cause big time problems in the compressor under normal operating conditions. [And just so I'm clear on this, isn't intentionally venting refrigerant to atmosphere (e.g., just opening the system without pulling and pumping out to a capture tank) against US federal law?] While it is easy to go out and buy gauges and a vacuum pump, capturing equipment is another level up.

 

Thats funny you say that because all the shops around here had to go out and buy this high $ equipment, Now this same eq. is sitting outside rotting. I asked one of the shops about this and they said the machines were junk and too costly to replace so they just vent it but wasn't that the reason the get rid of R-12,22 and replace it so it wouldn't effect the ozone? HA SCAM

 

Yes, as an ASE Certified Master Tech I am very aware of the proper methods for recovery and recycling of refrigerant. If the refrigerant circuit does in fact need to be opened, it will be done in the proper manner with the proper equipment that I have access to.

And not because it's law, just because it's the right way to do it and that's how I operate in general. So no worries there.

As for the car it's still there, not working. Busy work schedule has kept me away. Will try to get on it soon again.