When I take my 2000 OBW H-4 in for a timing belt replacement, will it be necessary for the dealer to replace the coolant?

yes, you will lose some coolant when a timing belt is done.

Depending on mileage, its not a bad idea, there probably gonna be removing the radiator anyway, so why not. I'm a mechanic, and when i do big jobs i like to reccomend the little things that go around the big stuff, If i'm gonna pull a tranny, i'm gonna reccomend a clutch if its been a while. I'd rather install it now, when its easy to get at, then later when its all back together and the customer insists that i broke what ever bit that they didn't want replaced at the time.

 

Make sure you get your seals done, and a water pump isn't a bad idea either if its got over 100K

will it be necessary for the dealer to replace the coolant?

more information would be helpful, it's hard to guess why you're asking this? the answer is "No." replacing the timing belt by no means requires coolant replacement. a proper timing belt job in my oppinion (and many others) includes a new water pump as well, because it's *right there* and easy to get too with the timing belt off. if the water pump comes off and part of the coolant is drained then it's not a terrible idea for the coolant to be replaced anyway. if they do make sure you get the 2.5 special additive/conditioner stuff as well, i'm sure they won't forget it, but mention it if you don't have a dealer do it.

 

but the answer to your question is a resounding "No." if that helps you out at all.

If you elect to have the water pump done, then the radiator will have to be drained of course, since the water pump attaches to the bottom radiator hose. New coolant will have to be added to at least make up for that loss, needless to say.

 

Also, if you want the front oil seals replaced, the tech will likely remove the radiator to give himself more room to change them.

 

But if you just want the timing belt replaced and nothing else, then no, you will not lose any coolant.