2017 3500 - replacing heater hoses and fitting, heater core flush

[cricha]

replacing the heater hoses on my 3500. There is a plastic 90* fitting on the top hose on the top of the engine. I've never seen a fitting like this, and dont know how it comes off. the new hose has a new fitting on it, and it appears that it just pushes on and locks itself in place. wanted to check here first before I cut the old one off.
Don't want to cause myself more problems.
A while back, my heater quit putting out heat. I checked here, and the problems folks had were either the core was plugged, or the air mix doors in the dash werent moving/opening. I disconnected the hoses and flushed the core with the garden hose, got a pretty good flow going through it. so it doesnt appear the core is plugged. I'm replacing the hoses because the top hose popped right at the firewall fitting. I can say that getting the hoses off the nipples at the firewall is not gonna be on my list of fun jobs.
if there is a way to get the plastic 90* fitting off of the motor , please comment! Thanks!

 

[TMyers]

replacing the heater hoses on my 3500. There is a plastic 90* fitting on the top hose on the top of the engine. I've never seen a fitting like this, and dont know how it comes off. the new hose has a new fitting on it, and it appears that it just pushes on and locks itself in place. wanted to check here first before I cut the old one off.
Don't want to cause myself more problems.
A while back, my heater quit putting out heat. I checked here, and the problems folks had were either the core was plugged, or the air mix doors in the dash werent moving/opening. I disconnected the hoses and flushed the core with the garden hose, got a pretty good flow going through it. so it doesnt appear the core is plugged. I'm replacing the hoses because the top hose popped right at the firewall fitting. I can say that getting the hoses off the nipples at the firewall is not gonna be on my list of fun jobs.
if there is a way to get the plastic 90* fitting off of the motor , please comment! Thanks!

You're supposed to push the two white tabs in and pull out at the same time to release the fitting. Mine was leaking and I had to break it to get it out. I think they go through so many heat cycles that they become brittle. Napa carries them.

 

[cricha]

Replaced both heater hoses and flushed out the heater core both ways with the water/air flush gun others have suggested, replaced cabin filter. filled coolant. Heater now works as good as new. Question: getting the spring hose clamps off the core nipples at the firewall was one of the most frustrating jobs I've ever done, mainly because I cant reach back far enough to get them with clamp pliers. What is the method any of you have used to get them off? any special tools that you have used? Is it easier to remove the passenger side fender well and go in that way? I would really like to know an easier way. I ended up using a 15" long pair of compound needle nose pliers. got to be a better way.
Thanks TMyers for the info on the plastic fitting!
One other thing I saw. By the time I got the hoses off, everything had pretty well dried out. when I took off the hoses, a substantial amount of what looked like casting sand came out of the hose. enough that I would suspect that other parts of the cooling system could plug up. Is this normal? is a coolant bypass filter something I should consider? what else could plug up from this? ANY advice on this is most appreciated!

 

[BigPapa]

Something like this.

 

[cricha]

Thats exactly what I used for the top hose, because of the angle and position, I couldnt get it on the bottom hose clamp. The long reach needle nose pliers are what I used for the bottom hose. These are about 15" long. But geez, there has got to be a better way...

 

[Ozymandias]

A bypass coolant filter is always a good idea, there is a reason for it why heavy equipment more then often comes with one from the factory.
It's the bean counters that kept it from going into our trucks.