Priming Pump

[Northern Mooniac]

Well...guess who also has two thumbs and needs a new priming pump.......fack.

Went to start the plane, hit the prime button and you could just hear the pump fade away.

Got the plane started with the high boost pump and took it over to my ame.

You can hear the pump click when you push the button but thats it.

So. I'm on the hunt for either a new pump or to get this one rebuilt. it's for a 320-LB

Any help would be greatly appreciated!

[kortopates]

It's the same pump for high boost, low boost and prime. If you were using the prime button you may be having a problem with the diverter or maybe even a broken primer fuel line.

I am sure your AME will figure it out ASAP.

[chrisk]

If it is the pump, there is a Weldon PMA part that was cheaper than a Dukes overhaul when I was in need a few years back. I second the suggestion to look for a broken primer fuel line.  I had the solder joint break at the injector some years ago.

[Hank]

You have a primer?? My Owners Manual just says to pump the throttle a few times before turning the key. Fancy modern planes! geesh . . . .     Next you're gonna say your seat adjusts up and down!

Edited April 25, 2018 by Hank

[Northern Mooniac]

He thinks it’s the resistor. Pump runs fine, and the divertor seems to work ok, but pump doesn’t run when the prime button is pushed. But he can’t find the resistor.

he figures it’s 30a

[xcrmckenna]

Sorry I shouldn’t of liked your post:) But I feel your pain.


Sent from my iPhone using Tapatalk

[N231BN]

The resistor is for the low boost setting, the prime switch uses high. The resistor is just inboard of the pilots right kneecap.

 

The primer switch is powered by a fuse under the switch panel. It is a double pole switch, one set of contacts activates the primer solenoid, the other runs the pump on high.

[carusoam]

Somebody ( @gsxrpilot ) has experienced something similar recently... 

The K is an odd bird when it comes to the electric boost pump...

You have one electric pump and three switches that operate it...

The pump has...

• prime
• lo boost
• hi boost

The prime feeds a different location in the intake then the other options...

This is just a memory for me, not actual experience...

My memories don’t last very long, so that thread is pretty recent... 

See if Paul has any additional input for this....

Best regards,

-a-

[Northern Mooniac]

He said the solenoid seems to be ok.

It couldn't be an issue with the electric pump could it?

[carusoam]

Usually when the one pump runs properly on the two switches, it is probably just the third switch and it’s circuit that isn’t working so well...

It might be as simple as cleaning contacts related to the switch.  Does the switch have an internal circuit breaker? These things can get dirty pretty easily.  Pretty easy to clean as well...

Pp thoughts only, not a mechanic...

Best regards,

-a-

[Northern Mooniac]

Well, he figured it out. When the primer button was pushed and it tried to flow fuel, the jets were clogged. So nothing could move. Because of this the fuse popped. So the system protected itself like it should and nothing was wrecked... I got away cheap!

[N231BN]

That makes sense I guess, the previous pilot must have not used the primer for starting.

[chrisk]

14 hours ago, N231BN said:

That makes sense I guess, the previous pilot must have not used the primer for starting.

Yes, some use the high or low boost for starting.

[kortopates]

On 4/26/2018 at 3:33 AM, chrisk said:

Yes, some use the high or low boost for starting.

True, but since this model has the priming circuit it's advantageous to use it since it less likely to start a fire from excess fuel going out the drains; especially with an engine that likes a lot of prime to start.