DeuceLV

OK, so I've replaced most everything in the cooling system (radiator, upper/lower hoses, heater valve & short hose). The long metal pipe connecting the resevoir to the passengers side of the radiator had the hollow bolt filled with what appeared to be rubber shavings.?..

This all started with the car boiling over. The heater valve was visually bad, as it split in the center and the ?plastic? was rotting away like a compressed cardboard. Replaced it and the hose. Tried refill and the radiator flange that connects to the top hose was in the same condition (brittle, and falling apart like wet compressed cardboard). Replaced radiator and both hoses.

I got a radiator off the bay from pro-radiators and unfortunately, I got a single core (OEM was dual). But they assured me it wouldn't affect cooling. So NOW it's all together and before starting the car, the temp sensor that screws into the bottom of the radiator on drivers side drips.

I only see a single o-ring on it to seal. Is that ALL that seals it? Is there an outer gasket? The sensor just butts up to the plastic/abs tank bowl, so I assume the o-ring is it. I'm going to buy a new o-ring, but how hard do you tighten this thing? I don't want to rip the threaded part out of the radiator, but I don't want to undertighten it either.

Also, the round bolt on the upper part of the radiator passengers side... At the end of the metal tube that runs along the top of the radiator from the resevoir. I have ?brass? OEM washers/gaskets I got from the Lexus dealership on EACH side. The parts guy and a mechanic didn't know if it used one or two. Does that washer butted up to the plastic upper radiator tank actually seal when the car warms up and the coolant system is under pressure? I tightened this bolt as tight as I think I can without breaking the plastic tank.




Any suggestions on the leaky temp sensor and that upper hollow bolt as far as sealing and tightening? Upper hollow bolt use a sealing washer on BOTH sides of the donut tube? Thanks!

DeuceLV

BTW, it's a 1990 LS400.

avalon42

iTrader: (1)

The hollow bolt you refer to must have a brass washer on either side of the banjo fitting. If it's missing on either side, it will leak.

As for the temp sensor in the bottom, there is technically a rubber grommet washer that wraps around near the sensor tip. Mine leaked as well, so I replaced that rubber grommet and I also added another rubber grommet washer to the base of the sensor also. No problems since.

DeuceLV

Thanks. Banjo fitting...! Accurate description too. Got that part solved then.

But the temp sensor... Seems like it would have a metal crush washer where it butts up to the radiator. I might try an extra o-ring there too if I can't get a good tight seal with just a new o-ring in the groove on the sensor itself.

Thanks.

Any other ideas? Keep em coming!

DeuceLV

Got a new o-ring for the groove half way down the sensor. It's a tad bit thicker too, in hopes of being a better gasket.

I also found a crush washer for the outer part of the sensor. I hope it being 1/16" thick isn't too much that the sensor doesn't go far enough into the radiator or the o-ring doesn't make it into some inner groove in the radiator it's supposed to sit in.

This is just driving me nuts. Looking at it, it should be straight forward and easy. Doing it ends up a PITA. Even the Lexus dealership can't tell me if that sensor uses a crush washer or not!