i had a similar issue, turned out to be that pesky little hose connecting from the top of the radiator (just below the cap) to the over flow res. i removed the cheesy spring clamps and used stainless hose clamps and the "mystery" coolant leak was solved. if it isnt sealed properly, coolant cant flow back and forth between the two (which it needs to do sometimes).....also as a pro tip....i replaced the cheesy spring clamps on the Power Steering lines and that solved the messy PS fluid leak...all this on my 99 LC with 290K miles
Coolant level goes down (1 Viewer)
- Thread starter YetiCruiser14
- Start date
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side note, that little tit that comes off the radiator just below the cap can be brittle, i broke one off on my '94 809 series years ago. so be careful 
man i wish i still had that rig, gave it to my brother back in 2002, he drove the crap out of it then sold it........
man i wish i still had that rig, gave it to my brother back in 2002, he drove the crap out of it then sold it........
JunkCrzr89
Competent Ignoramoose
Funny you mention this. I had an issue years ago with a 4runner in which the coolant level in the reservoir was never changing. I initially didn't think anything of it, but then I started thinking about ambient vs. engine temps and how the level in the reservoir should fluctuate regularly, which @2001LC mentioned above, and concluded that something was wrong. On a hunch, I thought the hose between reservoir and radiator might be leaking or clogged, thereby preventing the coolant to fluctuate in the reservoir as it should. I pulled that hose off and found about an inch-long length of packing-type foam inside the hose. I have no idea where it came from, but once I removed it, the coolant level fluctuation went back to normal.
yep, often overlooked!!!! and can cause lots off headaches!!! simple little piece of rubber tubing but very important for proper operation of the radiator !!!
I used the OEM clamps. Which you refer to as "cheesy spring clamps" on power steering hoses. They work exceedingly well.
But two issues come up:
1) Old clamp leaves impression in rubber hose. Always place clamp back in same orientation, by placing in impression. Not doing so they're more likely to leak.
2) Rubber hoses get old. The rubber shrinks in some cases, and so does not tighten snugly. In these cases I prefer replacing hose when I can. Aftermarket screw clamps is temporary, when I can't get the hose or running a test.
As for the cap to reservoir hose. What we've be doing is cutting of first 1 or 2" nearest the rad cap. Then it snug again. But yes, that is a cheesy clamp I don't like.
I've never seen one plugged, that's a new one.
But I have seen where the hose that drops to bottom of the reservoir, get hung up and inner shelf. Than reservoir will act as if empty (suck air) when still near full line.
But two issues come up:
1) Old clamp leaves impression in rubber hose. Always place clamp back in same orientation, by placing in impression. Not doing so they're more likely to leak.
2) Rubber hoses get old. The rubber shrinks in some cases, and so does not tighten snugly. In these cases I prefer replacing hose when I can. Aftermarket screw clamps is temporary, when I can't get the hose or running a test.
As for the cap to reservoir hose. What we've be doing is cutting of first 1 or 2" nearest the rad cap. Then it snug again. But yes, that is a cheesy clamp I don't like.
I've never seen one plugged, that's a new one.
But I have seen where the hose that drops to bottom of the reservoir, get hung up and inner shelf. Than reservoir will act as if empty (suck air) when still near full line.
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The coolant level in my reservoir is always low. I've never seen it rise up at all. Yet, after cool down, the coolant is in the neck of the radiator. This is a brand new (3 week old) CSF radiator with new CSF radiator cap. I have found no coolant leaks anywhere despite looking extensively multiple times.
