Coolant Resevoir Leak

[yank30265]

I have coolant leaking out of the top of my resevoir tank from the white sprocket looking thing; Id say it is a level sensor ; do these leak over time and where do I find a replacement? I also need to find a replacement band(clamp) that closes the air filter box; where can I find that?

[RDM]

The dealer or a salvage yard will have both, and yes the sensor does leak over time. Mine weeps just a little, I'm waiting until it's worse before fooling with it. Problem is the system is pressurized, so if coolant leak out, air can seep in. A bigger leak will draw in air and cause air pockets in the cooling system.

[AzHotLS]

This thread should help:

http://us.lexusowner...showtopic=53524

[killerFatty]

A new resivour from the dealer is about $250. I was lucky and found one in good condition on a parts car for $15. I imagine you could find that air filter piece on just about any parts car. That would be the first, and cheapest, place to look. A tip on the resivour: don't fill it up all the way to the lines. Leave a little extra room and the pressure will be lower. This slowed the leak in my old one before I could put the new one on.

[AzHotLS]

If it is leaking from the level sensor, then an O-ring will take care of it (as pointed out in the thread I linked).

[yank30265]

how does the sensor come out? does it pop out or screw out?

[AzHotLS]

Post 7 of the thread I linked..... sensor unscrews.

[dpellet]

Ok, had to get to the bottom of this issue as it seems many with 1st gen ls400's are running into problems in this area.

I started the process when my water pump went out last year, same time I replaced the thermostat and radiator as they were pretty worn but not leaking (yet). I was weeping fluid out of the top of the expansion tank from the level sensor just like many others. Tried to replace the o-ring but that did not solve the problem and weeping continued. I also noticed that there was never any built up pressure in the reservoir when removing the cap and I also suffered from a lack of heat from my blower on occassion and would have to rev motor to 2k+ to get the heat back.

I finally gave in and noticed a new res. on ebay, bought it and found out it was a replacement/upgrade to the former stock reservoir new part number is 16482-50010, not only did they put out a new expansion tank but also changed the level sensor new part #16485-50013 and cap which I do not have the part number for but is pressured to 88Kpa.

Now, when I bled the system, everything worked properly and I could see the fluid running into the exp. tank which was not happening before. Once the system loses pressure, ie weeping fuid, you cannot bleed it completely.

Now when bled, heat is perfect fulltime. Another thing that happens is your coolant sensor is misreading due to airpockets up high and many are likely suffering from a very rich fuel mixture especially first start of the day.

I also got as a bonus the stock sticker advising how to bleed system properly!!! Mine had worn off long ago.

Have to give credit though, the car never ever overheated even with such low pressure.

Hope this helps some..

Cheers,