quadrajet check ball assembly
 

I am re-assembling a quadrajet and after installing the check ball and retainer I can hear the ball rattle very slightly when the carb body is shaken. I've never tried this before with the other quadrajets I have gone through. I've thought the retainer was supposed to hold the ball tight to its seat but is this wrong? Is the ball supposed to float a bit?

Is it a new ball from a kit, if so can you compare it to the original?
They do move some, I mean they have to have play.

The old and new ball measure the same at .186. Thank you for confirming there is some play Steve.

Make sure you give that new check ball a light tap to form the seat to it. Otherwise there will be a slight stumble when you engage the accelorator pump.

Ah yah i saw that step in some videos. in some videos i saw you can drill out the seat a bit to get more flow and then tap the ball too.

The retainer does not hold the ball to its seat, or there'd be no pump shot at all.

The pump creates pressure in the system and in doing so, unseats the ball. The retainer simply limits the ball's upward travel...just far enough to expose the 2 fuel passages to the flow stream of pressurized fuel. After the pump shot, the ball drops down to the seat via gravity.. This keeps the fuel passages (to the discharge ports) full while the pump cavity refills.

When you refurbish your Qjet, use the old checkball to reform the seat, and throw the old ball away.

Very cool guys, and I did use the old ball and punch to form the seat. I filled the well with carb cleaner too to verify it wasn't leaking, it was so I tapped a bit harder and then it held the carb cleaner. Thanks again.

If you shake your Q-Jet and do NOT hear the ball rattle, THAT"S when you have a problem...