Bleeding/leak testing with an MCP35X

[DanNeely]

Having finally dealt with the gunk problem in my CPU block I went to connect everything up in my new loop and begin bleed/leak testing it. After doing the bend and twist routine to work most of the large air pockets into the res and get everything filled I connected the pump and a few 120mm fans (to give a larger load) to the PSU and jumped the ATX header to start it up. Both fans started spinning immediately; but the pump remained silent and none of the remaining bubbles in the tubes are moving so I know it's not just running silently.

The pump's sitting flat on my table (inside a rubbermade tub) with a filled reservoir above it, so priming shouldn't be a problem. Do I need to connect the PWM header to a system to get the pump running; or is my problem something else?

Pump's brand new and today's the first I tried to use it.

 

[DeathPrincess]

Shouldn't need to. You are connecting it to a molex? Try a different one to check its not the PSU.

Can't remember which is the inlet and which is the outlet on them... Is there fluid being supplied to both nozzles? Is it vibrating?

 

[DanNeely]

Did try a different molex plug without result. Both ports have water. No vibrations, but when I held the pump to my ear I heard it making quiet high frequency pulses of sound lasting a second or two stopping and then repeating themselves.

 

[DeathPrincess]

If theres no vibrations sounds like a broken pump, without the PWM pin the device should just run full speed. You can probably just return it as it's in the first few days.

 

[DanNeely]

Some googling indicated that it was possible to overtighten the barb on top. I loosened it 1/4 turn and it started running fine. Unfortunately I need to have the hoses coming out of the sides of my res and pump oriented the same way; so I'm going to have to drain and reconnect the loop.

Swiftech might've gotten the performance right with the 35x pump but the mechanical design needs a bit more tweaking.