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It won't lol, there is no reason for it to. I've had the car 30k+ miles and two years now and it's never moved from where I left it unless I serviced something. I fill it hot and purge all air and then check it totally cold.
The level has never moved, if it does there is a leak
That’s the trick, making sure it’s purged of air, I am certain anyone who is losing coolant hasn’t purged the air after a coolant flush or service where the coolant was drained. A void in this style system prevents proper circulation and that causes the coolant there to get extremely hot. This system with the high point being above the radiator cap is unusual, and few people even look for how to purge it. Once this has been done, any coolant loss should be solved.
This single and inexpensive hose, along with the pathetic spring clamps, is def the weak link of the entire cooling system. Replacing the hose and upgrading to actual hose clamps will improve the seal at both ends. You might be surprised what $10 and 10 min of your time will do for the coolant loss nuisance. Lexus part no.- 1637750040
Probably not such an issue in this particular location, but generally “real clamps” aren’t a good idea anywhere in the cooling system. The aluminum and even plastic ports can grow when heated up, and a worm geared clamp isn’t going to allow any room for expansion, and it’s easily possible to the clamp cut right through a rubber coolant hose. This is why all manufacturers use the spring style clamps that can flex when needed. They can get loose if removed and reinstalled a few times, so if they are failing and no longer sealing tight they do need to be replaced. I wince every time I see a pack of worm geared claims hanging up for sale with the antifreeze at Autozone. But the correct clamps are available on eBay etc
Probably not such an issue in this particular location, but generally “real clamps” aren’t a good idea anywhere in the cooling system. The aluminum and even plastic ports can grow when heated up, and a worm geared clamp isn’t going to allow any room for expansion, and it’s easily possible to the clamp cut right through a rubber coolant hose. This is why all manufacturers use the spring style clamps that can flex when needed. They can get loose if removed and reinstalled a few times, so if they are failing and no longer sealing tight they do need to be replaced. I wince every time I see a pack of worm geared claims hanging up for sale with the antifreeze at Autozone. But the correct clamps are available on eBay etc
Sorry for the confusion but I've made no mention of "worm" style clamps nor do I recommend them. A constant tension spring clamp is a "real" clamp. However, what you'll find on this particular hose next to the rad inlet is the sub-standard wire style which provides less tension than a loose rubber band.
Sorry for the confusion but I've made no mention of "worm" style clamps nor do I recommend them. A constant tension spring clamp is a "real" clamp. However, what you'll find on this particular hose next to the rad inlet is the sub-standard wire style which provides less tension than a loose rubber band.
my apologies, I recognized that I had misquoted u after making the post about “real clamps”. And misunderstood your definition of a real clamp. I should have edited it. I made the mistake of assuming you were referring to a worm gear style of clamp. So I often i find people who have replaced all the OEM clamps with a set they got from Home Depot. And I have seen the problems that can lead to many times. Few people realize they can cause a problem, so I try to warn people before they make that mistake. Your correct that the OEM clamp in this spot is just a simple twisted wire style, seemed like there must not be exposed to the high pressure that runs through the rest of the cooling system, and that’s why they originally opted for it. But if u found it to be vulnerable, then it’s good to know so I can check it out for any issues with my vehicle.
Yes mine looses a small amount of coolant from the reservoir tank if filled to the full mark when engine is cold.
If checked a week or so after top up it tends to be in the middle third of the tank. Somewhere around the 1/3rd above the low line when cold, rising to around the 1/3 below the high line when at operating temp (hot).
I have never seen coolant dripping from the hose that runs between the radiator cap and the bottom of the coolant reservoir tank. Nor coolant residue on the hose itself.
There is however residue on top of the coolant reservoir top leading me to assume it has expanded and come out the join of the loose fitting plastic cap before it can make it into the overflow hose which is at the high point of that loose fitting cap.
When I first got the LS, I used to worry about it and top it up every time it appeared lower than the full mark. But that just led to more and more residue appearing on top of the reservoir (And yes the coolant system was bled of air to be sure).
I stopped worrying about it and instead I now top off the coolant to the high line of the tank at service time (engine warm) and periodically monitor it between services to make sure it doesn't go near or below the low line (typically when checking the oil level).
It never has yet been near, at or below the low line in the 3 years I have been driving this car.
Yes mine looses a small amount of coolant from the reservoir tank if filled to the full mark when engine is cold.
If checked a week or so after top up it tends to be in the middle third of the tank. Somewhere around the 1/3rd above the low line when cold, rising to around the 1/3 below the high line when at operating temp (hot).
I have never seen coolant dripping from the hose that runs between the radiator cap and the bottom of the coolant reservoir tank. Nor coolant residue on the hose itself.
There is however residue on top of the coolant reservoir top leading me to assume it has expanded and come out the join of the loose fitting plastic cap before it can make it into the overflow hose which is at the high point of that loose fitting cap.
When I first got the LS, I used to worry about it and top it up every time it appeared lower than the full mark. But that just led to more and more residue appearing on top of the reservoir (And yes the coolant system was bled of air to be sure).
I stopped worrying about it and instead I now top off the coolant to the high line of the tank at service time (engine warm) and periodically monitor it between services to make sure it doesn't go near or below the low line (typically when checking the oil level).
It never has yet been near, at or below the low line in the 3 years I have been driving this car.
I second this.
Fill when hot, it won't ever leave between the two lines and when you refuel and check oil/coolant etc it will be right on full every time.
Don't run the car to check for leaks, you can have a pinhole leak that the coolant steams out of at temperature. The proper procedure is to pressurize the cooling system, preferably when completely cooled off, and look for leaks/verify the system pressure isn't dropping. If your buddy is a mechanic he should have one/know how to use one rented from a parts store.
I was seriously confused when I read this thread, as I have no such tank on my 2004 facelift LS430.
Turns out that the overflow tank is completely different in shape and location on the right hand drive LS430s.
On RHD models it is to the left of the air-filter housing in this photo (right side of the car)
Mine dropped from the Full mark when cold at 91k miles when I bought it in Jan 2018 to about halfway between the Full and Low mark last month at 132k miles.
I topped it off with about 100ml of ready mixed coolant.
I’ve owned three 430s and have driven them a combined 100k+ miles. Every single one was bone dry in the reservoir when I bought them.
And every single one lost a small amount over the years as I drove them.
The coolant overflow bottle is just a poor design on the 430s, unlike the 400s before them. The cap on top fits poorly, they crack easily, etc.
Basically what I’m saying is, fill it, monitor it, but don’t worry too much about it unless you have an obvious leak or are burnjng coolant (extremely uncommon on UZ engines)
Peaceboy, I believe you to be correct on this subject. I too was concerned when I purchased my LS 12 years ago. The reservoir was constantly stained with pink spots and I needed to top up on occasion,(very little added) but not excessively. I was told by the service manager that he had seen this on all the LS430s and I too when looking to buy a few years ago, noticed almost every LS had the stains on the reservoir. It is a poor design, and not to worry. Just keep an eye on things and you'll be fine. PS... I believe there is a thread on this very subject of reservoir staining.
01-04-22, 07:33 AM
