Emptying and cleaning BBi gas tanks

I took the sending unit off my gas tank and looked inside and yes, there was quite a bvit of crud at the bottom of the tank, now I want to clean the tank (the mechanic had assured me he had done that a year ago...when I had it in his care...)and get rid of all the debris. I know there are two tanks, but the sediment seems to be in the tank on the right (passenger)..can drain both tanks at the bottom, but how do you get rid of the debris...what do you flush the tank with?

Any help here please would be appreciated. Will undertake project first thing tomorrow morning.

Incidentally, the sediment came from a very corroded gas sending unit which I have replaced already.

>what do you flush the tank with? <

Believe it or not, Gas Tanks are flushed with "water". In a simular manner as if they were to be welded on. Then blown dry with air and then allowed to fully air dry before putting back into service.

On Boxers &amp; 308 series cars the tanks can be flushed in the car. Tanks drained, center crossover pipe removed, tanks flushed, car is then jacked up one side at a time using the jack points to allow the residual water to drain, blown out with compressed air, crossover with new hoses reinstalled, 1 gallon of fresh gas refilled, then this gas drianed, refilled. Used gas disposed of properly at a Waste Oil recycling station. Done.

I always install new fuel filters after this procedure also.

Have to tell you Coach that dirty Aluminum Gas Tanks is a fairly rare occurance. Usually caused from filling the tanks from a bad gas station.

Regards, JRV

well, a year and a half ago, I lost my gas gauge and discovered that the sending unit was completely rusted....i guess from sitting around...so I changed it...but did not flush the tank. Shortly thereafter, I had my car worked on and both times the tank was flushed, so I am guessing that I should find a new Amoco high test station; but their gas always looks so clean...oh well...thanks for the advice.