why won't the ballast fill?

My buddy has a 2002 Supra direct drive. It has front and rear ballast. For some reason the rear one never wants to fill all the way. It fills about 1/4 way and stops. The front fills all the way up but it only does it when it feels like it. Whats the deal? Is there a trick to getting them to fill? The pumps have been looked at and replaced, but they still don't like us..................

maybe its broken???????

just a sugg. but try to drive about 5 mph while pumping sometimes that helps to force water in so the pump isnt sucking air. my 2004 san sometimes i have to go forward to get the port side to start to pump. I even turn the pumps on when im going to where I board at 25 mph.

I have an 02 Mobius (pretty similar to the Supra)and in order to get the pumps to start filling at a decent rate, I need to drive about 25-30. Some of the intakes need to be force fed water to get the pumps to prime. You might also want to look at the hose position when the back bag is 1/4 full-the weight of the water might be kinking the hose not allowing any more water to fill. If that doesn't work, start hanging out at Jenny Craig and make some friends.