I recently purchased a 2006 GX 470 currently with 151,000 mile. I'm very pleased with the vehicle and my first Lexus. The front windshield washer no longer pumps washer fluid to the front windshield, however the rear washer works fine.

Does the vehicle have two separate pumps for the front and rear, and how is the washer pump accessed ?

 

Behind front bumper passenger side.

 

Yes, separate pumps.