Is my pump working correctly ?

I have a MCP350 pump. My temps have been high with my WC system in two different rigs. I tested the pump out in my sink to see what the flow rate was. It couldn't pull the water up from the sink, once I lowerd the pump it did flow but the rate didn't seem too high the water gently flow instead of looking pushed. Does it seem like my pump is working correctly or not ?

Well without a closed loop the pump cannot pull up because it is not self-priming from what I have read. I always have it so that water is "draining" into the inlet of the pump.

Bryan d

The pump can't suck air, you have to PRIME it. The instructions should have clearly stated this. If I understand what you did correctly, I'd be suprised if you didn't damage the pump.

The pump must be flooded, and remain flooded throughout all of its powered operation.

When you tested its flow, was it just the pump, or were there other components attached as well?

I have the reservoir attached to the pump. I did fill the reservoir up, but once it ran out it didn't suck up the water from the sink, I am only talking for a second or two. It is working the same way as before.....whether that's good or bad, I am trying to find out. When it was pumping water it was not shooting out as I thought it should. There is something in my loop keeping the temps high, either this or the apogee. I have changed rads two times already.

Alrighty, so you had the res hooked up to it when you flow tested it. Was this the only component hooked up to it at the time?

Without waiting for your response, if you in fact had all your loop components hooked up to it and then you tested the flow, I wouldnt expect nearly as much flow as if it were by itself. If you were getting really low flow without any other components, then there might be a problem. I don't know enough about that pump or problems associated with it to say what could be wrong if your getting poor flow.

Being that the pump is 3/8, it doesn't have as much flow as some of the other highly regarded pumps like the MCP655, but it makes up for it with great head/pressure (IIRC).

Pumps can be instantly dammaged if run without fluid. I too am suprised that the pump is not severly damaged.

having fluid in the res is NOT the same as priming it. you see if you just allow the water gravity feed in it the first time there will be enough air trapped inside that the starting occilation of the pump can throw it out of true. this is how most pumps are damaged.
the fluid not only acts as lubricant and coolant but physical force disipation aka a bumper that keeps that first start up occilation from being to strong and throwing the pump out of prime ( hence the word priming the pump)

This was a MCP350 with the 1000 res attached to it, so the res flows right into the pump. It works abot the same as when I got it.