When I close the lid to start to make coffee a stream of water comes from the rear of the coffee maker
Is it a steady stream or does it stop after a second or two? What model is the unit?
Can't be much help without a model number. However, beings that this happens after "closing the lid", I surmise that the water leak occurs after pouring water into the top, thus narrowing down your Bunn brewer to likely being one for household use.
If that's the case, then it's not repairable. It's cheaply made (mostly plastic inside) and parts aren't available to fix it. So your only option is to throw it away and buy a new one.
FWIW: Although a search for a solution on your "Bunn" product brought you here, we can only address issues on Bunn COMMERCIAL coffee brewers. They're significantly more expensive and built to a much higher standard of quality, so parts and service for them are available.
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