Put back the upper hose 7. Let engine continue running with various speed. keep an eye on the temp gauge.
We're OK up to here. But without a thermostat, coolant won't be forced to flow through the radiator and will prefer to take the bypass channel, _especially_ if your radiator is a bit occluded. You must have a thermostat installed, or a bypass thermostat (one that is forced open). The thermostats in MB's are, in electrical parlance, SPDT switches, not the more common SPST type. There's a secondary valve surface that cuts off the bypass passage at the same time it opens up the radiator passage. -- Jim
