Ls430 Rear Ac Disabled

DaKa · September 30, 2015

I had the misfortune of some damage to my LS430 AC pipe just above the near side drive shaft/differential.

This was caused by a stupid local non Lexus mechanic that didn't put the drive shaft nuts/washers back in with enough torque or 20p worth of lock-tite metal glue when the rear bearing hub assembly was replaced.

The washer threw out when the nuts came llose and damaged the AC pipe badly - what a costly mistake and as it happended 9-12 months after the job was done I had no easy recourse to the garage.

It is a pig to replace, so my friend mechanic using a splice/lok kit that I purchased dispensed with the rear AC (as access to pipes was impossible) and instead completed the AC loop by joining the AC pipes somewhere underneath the car between the near side front and back passenger seats.

Great I thought - who neads rear AC.

However, it went straight to Formula One for a regas and they confirmed no leaks present and filled up the front AC as per specification 650 ml?

Sadly, no cold air, but not leaks either - so what's going on?

Normally, the air vents when on max cold previously moved from side to side as standard, but now they don't move at all making me think it could be something electrical. I didn't check the AC after the pipes were spliced, so now don't know if the probelm was caused by the disabling of the rear AC or, something during the gas recharge.

Any ideas of what to try?

cruisermark · September 30, 2015

hi

disabling the rear AC system on the 430s is a common practice - the reason for this is the pipes start to corrode and perish causing loss of gas and replacing the pipes as you know is not easy and requires alot of dismantling therefore a cheaper easier fix is to do what you have done.

i think you need to start to see whether to compressor is kicking in at all and take things from there - if it is then your problem is elsewhere - if the compressor is not coming on then you need to investigate why not starting with simple things like fuses

good luck

DaKa · September 30, 2015

_{Thanks for the information that I'm not alone in re-routing the AC flow and disabling the rear.}

_{This lets me know that there are no sensors or things that would cause the AC not to blow cold.}

_{I guess it could be a fuse - could this have been done during the regassing. Should I take it back to them?}

_{They mentioned it was hard to reach (heat from the engine) the low pressure pipe under the bonnet and waited 20 minutes before doing a pressure check - could something have been inadvertently pulled out and disconnected?}

_{The mechanic who spliced the pipes for me was underneath the car nowehere near the engine bay and with the ignition off, so I don't see how he could have affected anything.}

_{As mentioned, prior to today, even with no gas in the AC, if you set the AC to max cold and Auto the airflow outlets to the driver/passenger in the centre swivelled from side to side. This is now not happening. Do you know if there is a fuse specific for this?}

_{It certainly sounds like the compressor starts (notable change of tone from the engine when Auto AC engaged) - I'm rather ignorant of AC so need an idiots guide otherwise I'll have go back to my mechanic - awkward!}

hihihi · September 30, 2015

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DaKa · September 30, 2015

Aaahh, the guy at F1 did mention that he took 10 mins fiddling with th climate control settings. I will check this a sap. Thxs

DaKa · October 2, 2015

Indeed it was the F1 guy that fiddled with the controls and switched the oscilating fans off - Doh!

I do however have a lack the kind of cold air I would expect through the vents, it's more of an autumn draft, but definitely colder than the ambient temperature - so something must be working. It's as if there is still a lack of refrigerant - they only inserted enough per the pront AC spec 650, should they have put 900+?

Does anyone have a novice guide of things and were/how to check, or will I need to seek out an AC specialist and cough up some more cash?

Thxs

ambermarine · October 2, 2015

Damien

Take a look in the engine bay when the A/C is first switched on there is a thick metal pipe, it as a valve on it with a grey plastic cover, on the passenger side of the car that goes from the firewall ( Engine Bulkhead) alongside the engine to the radiator/condensor at the front .This pipe will have frost on it if the A/C is working to capacity. It will not frost up when the engine bay is warmed up so check it at first start up.

You will need to remove the top plastic engine covers to view this area.

Loathecliff · October 3, 2015

"they only inserted enough per the pront AC spec 650, should they have put 900+?"

With the rear end capped-off you want less.

DaKa · October 6, 2015

Picking up on the wording here - perhaps my mechanic mate has made a gaff?

The AC pipes that run from front to rear, I presume one delivering (10 mm) insulated pipe and the other returning to the front AC (8 mm) not insulated, instead of being capped of they were joined as per diagram.

I thought that a loop was required - am I wrong?

Loathecliff · October 7, 2015

The pipes to the rear on mine are chopped and capped individually just after the T joints.

cruisermark · October 7, 2015

Picking up on the wording here - perhaps my mechanic mate has made a gaff?

The AC pipes that run from front to rear, I presume one delivering (10 mm) insulated pipe and the other returning to the front AC (8 mm) not insulated, instead of being capped of they were joined as per diagram.

I thought that a loop was required - am I wrong?

AC LS430.PNG

well if my knowledge in plumbing is to go by i.e flow and return then that looks ok to me

DaKa · October 7, 2015

Replies appreciated - albeit contrasting.

I have the distinct feeling that the pipes should have been simply blanked off rather than connected.

If Stuart's AC is working on the front (and I presume that it is) then my mechanic connecting the 10mm to the 8mm pipes under the passenger seat to create a U-Bend flow would appear wrong!

Expert comment sought before I take it back.

Thxs

cruisermark · October 7, 2015

is it connected to something at the "rear AC"

DaKa · October 7, 2015

As per diagram and heading - rear AC pipes disconnected.

DaKa · October 8, 2015

_{Not hearing more, I checked some stuff out on Youtube and it appears that my pipes should have simply been blanked off separately and not connected.}

_{https://www.youtube.com/watch?v=Fz2obM-laOA}

_{I know the car in this example isn't the same, but the problem on this youtube is and I can only imagine the plumbing is the same..}

so I'm back to get the gas removed, connection blanked off and regassed - let's hope I'm right this time and don'e have to reverse things back.

Loathecliff · October 8, 2015

Damien, assuming the rear pipes have not been removed, you should have six pipes because you once had two T-pieces.

The blanking should been done on the rear pipes after the T pieces.

(Before I Iooked at mine I asked on here where all this took place & got an answer from a Lexus mech. who said the blanking was a common job when the rear pipes leaked.

When I looked, the job had already been done.)

DaKa · October 8, 2015

Thanks for the private messages.

You must appreciate that I am ignorant of AC pipework and terminology.

I can confirm that the rear pipes have not been removed, but I don't know where I could see 'six pipes because you once had two T-pieces'.

It's good to know that the blanking should been done on the rear pipes after the T pieces. But again, I don't know where the T pieces are and does that mean towards the front or back?

If Lexus say blanking is a common job when the rear pipes leak it would be good to have a write up or diagram that shows the pipes before and after as I have tried above.

Any takers?

Loathecliff · October 8, 2015

Rough 'map': Under one of the long narrow plastic panels nr. the front passenger door, close to the exhaust.

DaKa · October 8, 2015

Many thanks - this is indeed just about where the pipes under the car have been cut.

It appears to be just 1 x 8mm and 1 x 12mm pipe.

I've blanked off the 8mm today with a compression joint, but only had a 10mm end compression joint so will need to wait for the larger 12mm to arrive (ebay).

Just now wondering if the blank off needs to be slightly further towards the front where I can see a compression join - to the front of the plastic panel under the passenger door?

Will my brass compression end caps on these aluminium compound pipes take the pressure - I get the feeling that they will really bite into the softer pipe and are good for what is required. Are there any links to custom compression joints that I should try?

Loathecliff · October 8, 2015

My turn to be confused now. - Please flip the car onto a mattress & take some pics.

DaKa · October 9, 2015

It will be the WE before I can take some actual pics.

I found the image below on the web that shows where my pipes have been cut and where I will blank them.

My mechanic erroneously joined the two separate pipes together usng a splicing kit 8-12 mm. The AC gas has been removed and just awaiting confirmation on where to blank off before the gas is re-applied.