1418 mercedes hot water heater

[jkis]

This may be of help for others too
The hot water heater at the front of the bus has never worked,
Was thinking of putting a diesel heater in the original space.
But putting a house water heater in that I could run of the same system made sense to me.
Until I fitted it all up and had no water flow.
This bus has 2 waste gate valves 1 at top of motor and another at the bottom.
I blew most of the water out of the heater lines topped up the resivor use some duct tape to make a plug on a air duster set the air regulator to under 10 psi turned on the top valve, and had the return line disconnected and into a drum,
Applying air pushed the coolant thru along with some dirty water, reconnected the hose and all is working great.
Cheers stuart

[T1 Terry]

Good tip, a mix of water and air pulsed through the heater core and the radiator core in the reverse direction to the normal water flow will often move rust scale that has blocked the core tubes and stopped the water flow ...... but ....... be real careful about the pressure until you see the water actually flowing out the heater core hose, the tanks on each end of the heater core aren't real strong and they can bust along the seam ..... makes a real mess up under the dash

There are radiator filters that fit into the top radiator hose that filters out these rust scale lumps that block the radiator and heater core. Well worth the effort to install and service regularly until the filter mesh remains clean between services, then the service schedule can be extended.

If the cooling system doesn't have any aluminium parts in it, a strong mix of phosphoric acid (the rust converter stuff for body repairs) in clean water run through the cooling system for weeks/mths until the rust scale stops appearing in the filter does a brilliant job of removing rust scale that has built up over many yrs. The radiator over flow bottle will need to be emptied and cleaned regularly as well, the smaller rust particles are converted to a phosphorus powered and that ends up in the over flow bottle.
Once the filter stops blocking up, a good reverse flow flush to get the remaining white powered out and any remaining phosphoric acid, then refill with rust inhibitor and anti freeze if you plan to travel in the cold country.

T1 Terry