10-10-2016, 10:04 PM
(This post was last modified: 10-10-2016, 10:07 PM by carlukepeugeot.)
Yeah, as above, the filler neck of the the radiator is lower than the highest point in the system (ie the heater matrix). So in order to get coolant all the way to the matrix and push all the air out, you are supposed to get / make a header tank. I usually use an upturned 1L coolant bottle. Cut the bottom off, and use O rings to make sure that you get a water tight seal between the bottle and the filler neck when it is inserted. You also need to plug the overflow hole on the side of the filler neck otherwise it will all pi5h out!. You basically want to fill the system, working your way from the bottom bleed screw up to the one at the matrix level - ie open the one on the rad top until coolant flows out clear of air, then close. Now repeat with the one on the hose from the heated fuel filter. Fill your makeshift header tank to whatever level is required to achieve this.
By the time you get to the heater matrix one, you will need to fill the header tank quite a bit. Again, once coolant runs clear of air, close it off. Now run the car and let it heat up until the cooling fans kick in (keep the header tank fairly full). The engine should take in the coolant in the header tank. Lastly let the car cool. Hopefully all the coolant went in from the header, which you can then remove and just top up the level if required. Remember, it isn't important whether or not you have the hot / cold valve set to hot or cold, as on the 306 the valve adjusts the amount of hot air which is delivered rather than the amount of coolant flow through the matrix - on the 306 the matrix always has maximum coolant flow, one of the reasons it is so important to do all this - the matrix forms part of the required coolant volume for effective cooling of the engine.
By the time you get to the heater matrix one, you will need to fill the header tank quite a bit. Again, once coolant runs clear of air, close it off. Now run the car and let it heat up until the cooling fans kick in (keep the header tank fairly full). The engine should take in the coolant in the header tank. Lastly let the car cool. Hopefully all the coolant went in from the header, which you can then remove and just top up the level if required. Remember, it isn't important whether or not you have the hot / cold valve set to hot or cold, as on the 306 the valve adjusts the amount of hot air which is delivered rather than the amount of coolant flow through the matrix - on the 306 the matrix always has maximum coolant flow, one of the reasons it is so important to do all this - the matrix forms part of the required coolant volume for effective cooling of the engine.