Cleaning inside pasty expansion tank

[Mick Day]

Not a good idea to put it in the dishwasher: bellhousing came out OK but expansion tank made it smell enough for SWMBO to notice...........

[Graham D]

I've just done this on my 98 car.

 

I soaked the expansion tank over night in Daz, that removed about half of the gunge. Then I poured a couple of dessert spoons of sharp sand into it and half filled it with water. After shaking the mixture about for approximately a minute 90% of the gunge had gone. The sand and water treatment was repeated once more and it was like new.