I am replacing the small hose from the water pump to the heater hose and there is a small black plastic piece that connects the hose from the heater core to the water pump about 5 inches from the water pump, mine broke. Can I simply use a heater hose coupling to connect these 2 hoses back together, or is that 'valve' absolutely necessary? Am working on it right now, so quick response from anyone who knows this is greatly appreciated?

 

that is a restrictor. If you were to look thru an unbroken one, you would see that it is about 1/2 the hose opening. It isn't a valve. This is to be sure you have more flow through the engine instead of the heater core. Most cars eventually leak at those crimped on connections at that restrictor. When my car developed the usual heater failure I noticed that was leaking. I cut the hoses off and replaced them and put hose clamps on the restrictor. I did run without it in place for a couple of weeks (and boy does the heater get hot when you do) but it's best to put it back in place. I think if you buy a new one, it will have both hoses already crimped on to it.

 

The piece is broke on mine, I simply replaced it with a coupler for the lines. So the only side effect is that the heater will get even hotter with out that restricter? There are no other negative side effects are there?

 

i've been running without it for months now, no side affects at all. engine temperatures havn't changed one bit, and i live in hotter-than-hell florida.

 

mine broke too a few months ago....a temporary fix was fine but I replaced it for the hell of it a few weeks later....