I don't think that there is anything that is cooled by the coolant other than the engine...I would make sure that all of the hose clamps are on tightly, I have seen them pop off before and release tension. Also, the water pump is hard to detect. You may just put your hand or finger under it and see of the weep tube is leaking. I have seen the small hose that is on top leak at the connection to the radiator. Good luck. I'd keep filling it untill found!!!
1992 500E (very soon I hope
1981 280GE SWB
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