Mercedes 709D coolant reservoir

[Dazed]

Hi all, got a 709D and unfamiliar with the engine bay of this bus. I am trying to apply the layout logic learned from many years of owning cars to the problem and think there is a problem.

I have had a local mechanic get it through the test and we have started on converting the interior and therefore have not driven it. I am not the person driving or converting or repairing the bus due to illness and disability.

As the vehicle is not being driven we have disconnected the two batteries while this was being done I removed the cap of what I thought was the overflow tank from the radiator. I was very worried to see that this tank (to the left of the rad) was empty.

So I need to confirm that this is indeed the overflow tank and then I can panic about antifreeze and leaks and see about getting it fixed. I am keeping my fingers crossed that no overheating has occurred. :-(

 

[maingate]

If it is not being used, I would loosen off the bottom radiator hose and drain the engine completely. Get the mechanic to blow the air out of the heater as well.

I have no direct experience of the Merc so cannot help but you are probably right. As an afterthought, before draining down, top up with water (and run the engine if possible) to look for leaks. It could be a burst hose but if it has stood unused in very cold weather without antifreeze, normally a plug pops out on the engine block if it has frozen. These are normally straightforward to replace. I would not go into panic mode just yet.

 

[Dazed]

It could be worth thinking about whether it has had antifreeze and certainly draining down while not in use is a good idea. Because I am not sure if the tank is for coolant and because it is empty I am unsure what antifreeze, if any, is in the system.

I must admit I was so surprised that the tank was empty that I haven't checked the obvious by looking in the radiator and also whether the radiator also has a pressure cap.

I will need to fill up with coolant, of course, to get it to a mechanic; my wife will drive. I won't be able to check for leaks myself or do any work on the bus, unfortunately, which is very frustrating.

 

[Deleted member 207]

Overflow tank should have a standard radiator style cap to ensure that the system can pressurise. To check if there is coolant squeeze the radiator top hose and you should hear some coolant squishing around - if not its probably empty - if the coolant is just low you may get a bit of overflow to the tank.

Its best to have coolant in the system even if laid up for a long time, empty coolant can lead to rust.

 

[Wooie1958]

Apparently this is Mercedes 609D 709D 811D 814D type header tank to suit vehicle 1987 - 1996, T2 type

It`s not a good idea to leave it without coolant for too long because seals can dry out and rust sets in.

 

[leosaphira]

Apparently this is Mercedes 609D 709D 811D 814D type header tank to suit vehicle 1987 - 1996, T2 type

It`s not a good idea to leave it without coolant for too long because seals can dry out and rust sets in.

Indeed it is, I got the 611D model - I will be getting mine sorted out soon as I have a air trap on the heater matrix to the cabin heater as it blows out cold air only.

 

[Lorry Ball]

Hi all, got a 709D and unfamiliar with the engine bay of this bus. I am trying to apply the layout logic learned from many years of owning cars to the problem and think there is a problem.

I have had a local mechanic get it through the test and we have started on converting the interior and therefore have not driven it. I am not the person driving or converting or repairing the bus due to illness and disability.

As the vehicle is not being driven we have disconnected the two batteries while this was being done I removed the cap of what I thought was the overflow tank from the radiator. I was very worried to see that this tank (to the left of the rad) was empty.

So I need to confirm that this is indeed the overflow tank and then I can panic about antifreeze and leaks and see about getting it fixed. I am keeping my fingers crossed that no overheating has occurred. :-(

The orange/brown tank is not an overflow tank but a header tank, the rad it self does not have a pressure cap, there is a max mark on the header tank about 2-3 inches below the cap, so long as there is some water/antifreeze in the tank it should be above the top of the rad,
If you have a air lock, fill the tank to the top and leave the cap off and drive a couple of miles and check the tank again, top up to correct level and put the cap back on...

I have had my 709D for about 10 years....do a google search for "K624ORL"


Lorry :drive: