I've just signed up as a forum member... I live in Scotland, in the UK, and I own a 2002 IS300 Sportcross. Normally the British Lexus Owners' Club forums are my first port of call. But I'm hoping with this latest problem to tap into the much wider pool of knowledge among US owners about air conditioning issues. I'm seeking advice on aircon issues that may well be common to other Lexus models and indeed other makes of car.

There are a couple of "pinhole" leaks in the high-pressure pipe (aka the "liquid line") of my car. I know where they are because the R134a 'gas' refrigerant had fluorescent dye added, and this shows up in the light of my UV torch. The condenser is corroded and also leaks, but that is easily replaced. Right now the system is empty of gas, the a/c doesn't work, and there is no point in trying to recharge it.

The high-pressure pipe is a single piece which runs from the condenser in front of the radiator, up to just behind the LH headlight where the filling-connection and the sight-glass are part of the pipe. It then goes down by the ECU and along the chassis-rail beside the engine block, and up to a connector in the firewall which links it to the interior of the car. I think it's the same part, and follows the same route, in both LHD and RHD cars. See attached image from the parts-diagram.



The bad news is that this pipe is a single aluminium tube with bends and turns, is therefore not flexible, so is tricky to disconnect and remove. And the replacement part, OEM part no 88706-53050, is discontinued and no longer available from dealers or any other UK supplier as far as I can establish. Ordering from the US is probably not realistic as the line, although lightweight, is long and fragile, so shipping would be risky and expensive,

So to get my a/c working again, I have to replace the condenser (not a problem) and that high pressure line. As a new replacement line is not available, I have three options:

1) find someone breaking an IS300 and hope that the high-pressure line can be removed intact and undamaged. A bit of a gamble, as any such second-hand part will be about as old as my original and possibly equally prone to leaks. But I'm searching....

2) have an aircon specialist make up a complete replacement part using mine as a pattern. This is possible, but expensive and hard to arrange as the only specialists I have found are a long way from me (I live in the Scottish Highlands). Removing the existing pipe complete is a challenge. Sending it by courier to an engineering firm elsewhere in the country would also be costly and risky.

3) try to have the original pipe repaired. Welding/brazing the pinholes is difficult and not certain to succeed. An option which I have discussed with a local hydraulic-hose workshop is whether the main length of the tube can be replaced; keeping the connections at either end, and using crimp-joints or compression-fittings to put a new section of pipe in in the middle. This raises two questions. What pressure does this pipe (the high pressure a/c line) have to withstand? And - linked to that - what could a replacement section be made of? Could it be made of brass... or copper... or even suitably high-spec reinforced rubber or polyurethane etc hose? The advantage of this last option, if it is technically possible, is that a flexible section of hose would make reinstallation a lot easier.

These are obviously questions for an aircon expert. Any advice would be welcome!

 

You can get aftermarket Stainless braided lines made at a hydraulic shop. They may not have the line appropriate but can buy online kit and have them put it together.

 

Thanks @2001SolarY . That is certainly one option I might explore. I have a local hydraulic workshop nearby, but they are involved more with offshore oil tech than with automotive work. The liquid line in my Lexus a/c system is 8mm or 5/16" (outside diameter) aluminium. I'm told the system operates up to a max pressure of 350psi. I may need to give the workshop more detail on exactly what sort of hose to use. I understand that a/c gas (R134a etc) either attacks, or can percolate through, some types of rubber, plastic, nylon or polyxxxx hoses. Can you advise on what size/diameter of braided hose would be appropriate? And what sort of hose-material is resistant to a/c liquids and gases?

 

You can get hose and fitting kits from online vendor like Summit Racing and others. They work fine on A/C lines. I have used them on hot rods before.