please remember that the cooling system will need to be re-bled after replacing the heater control valve. Only top up with distilled (not purified or tap) water, or toyota long-life or super long-life (RED/Pink) coolant.

 

So I did finally replace the HCV myself a few weeks ago, and while it was a fairly straightforward job, it of course took me much longer than I anticipated! After I removed the hose I saw that the end of the HCV tube had broken apart due to being brittle with old age. Removing the hose from the HCV and then sliding it back in place were by far the hardest part of this job. Tight spaces makes it hard to maneuver around in there and I had to finagle with it for an hour or so probably. I did clamp off the hose to prevent coolant from leaking but I don't think it was really necessary since the HCV is the highest point of the system so not a ton of liquid to spill at that point in the loop.

The part is easily purchased from a dealer or an online shop (I think I bought mine off a dealership's ebay store). For those looking to do this themselves it is a straightforward job, just allot a couple hours to allow for the difficulty of removing and reinstalling the coolant hoses onto the HCV.

Thanks for all the guidance and help here! If anyone else wants to attempt the job I'm happy to answer any questions about my experience.

 

The typical age of these parts one may be advised to have replacement hoses on hand in the event they split on removal. Struggling with a hard hose is not fun and the fresh ones go on-off so nicely.

 

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Even if you choose to buy a used valve from a salvage yard having new fresh, and pliable, hoses on hand will make life MUCH more pleasant.

 

if new hoses would be more pliable to slip on and off that would be great. how difficult is it to replace the two hoses involved in the HCV replacement? don't think I would attempt to install new hoses unless it was a relatively straight forward procedure.

 

You recently replaced the valve right? You should have first hand working knowledge of the level of difficulty...

It's the new hoses that make the job easier. If I were replacing my HCV I would replace all 3 and I would buy them from Lexus or Toyota. You don't want to use cheaper universal hose and end up with a kink in the bend that could cost a lot more in the long run.

 

yeah i did replace my HCV - however I did not replace the old hoses. was just wondering out loud how easy it would be to install new hoses, that's all. thanks for that diagram, should be helpful for anyone looking to tackle this project DIY.