01 B3000 160,000mi. Yep its plugged. ive tried the water hose with about 75lbs I'll try too reversing the hoses too? im thinking air now. the thing must have been a rust filter? So any other ideas?

 

Pull out the dash and swap it out

Don't want a be a Debbie Downer but there is no other fix, so don't waste your time
Even if you got partial flow back it won't be much heat if any

And because the is no flow then there is NO rust protection from coolant flowing passed the metal parts, so it WILL start to leak at some point unless you just bypass it now

 

Guess what I reversed the hoses and boom. when I replaced the heads I could tell there was lots of rust slug in the #3 and #6 water jackets. I should have tried and suck it out or? I made a mess when I blew air to clean things up. I have a feeling that when it first started some of the bigger stuff went right to the heater coil. only because when I reversed the pressure hoses, it went blop and the all the water was clear. fingers crossed. because I live in Hawaii I really don't need it but I do like the defroster some times.. if it starts leaking I'll bypass it. thanks Ron for your help!