Nice day Saturday, so I crawled under the truck and tried to follow the line. Looking along and around the passenger side frame rail, I found the hard lines for the rear heater/ac run there, but no rubber hoses. Hmmmm
-Then I got smart: Thinking that since no fluid shows up on the ground the issue is most likely at one end or the other. I pulled the 3rd brake light off and disconnected the hose to the washer head. Sucking on the hose revealed no open line, (and no fluid) so I hung the hose out disconnected from the head, and ran the rear washer. A few seconds later I got some questionable looking fluid out, so I ran it long enough to know I had purged the line of old fluid. Since I've found heads plugged in other vehicles over the years, I blew through the head but found nothing indicative of a blockage.
I connected and reinstalled the brake light assy and it now works fine. So, no smoking gun, but perhaps some foreign material in the line or contaminated fluid was blocking the spray head orifice. It s a new vehicle to me, so no idea of its previous care or history.
Thanks for your help HMAC!
Monday, October 31st, 2016 AT 11:56 AM