M1009 little heat to no heat

[JAD561]

I have seen many posts on no heat / heater core problems. Some users have refered to napa replacement cores. Does anyone have a part number ? I think i might need to replace mine. I pulled the thermostat and replaced it with the hockey puck type. Did this last week when the temp outside was 10 degrees. The gasket sealant was freezing as i applied it. Bolted everything up anyway. Had a little heat while parked, no heat while driving. I guess the engine heated up the frozen sealant because i sprung a leak after a few hours when the system was pressurized. Re-tightend the bolts. No more leaks, but now the heat blows cold all the time. Checked the cables under the dash. Everything is ok there. Noticed that the heater core hose to the engine was warm, the core hose to the rad was cold. Thinking i'm either air bound or the core is plugged. I will run it tomorrow with the rad cap off the see if we can bleed any air out, or i will replace the core. I don't want to take a chance on doing an engine cooling system flush. If the core is plugged, i don't want to possibly break something loose that could be holding the core together.

 

[OL AG '89]

try disconnecting the core hoses in the engine compartment and flush water through them.....
see if you get anything out of them...
if the water is frozen.......!!!! Try blowing out with some air.....
you won't loose alot of fluid if you are careful
If the core is toast and not working you can't break it much more by flusing indepedent of radiator....

 

[Blood_of_Tyrants]

Get some CLR (calcium, rust, lime remover) and soak your core in a 25% solution of it making sure that it is filled with the solution.

 

[JAD561]

Ok. I will try both methods and see what happens. Thanks

 

[JAD561]

I tried flushing with water, didn't work. made a set up with a schraeder valve, and used a small compressor. We ran the psi up to 30, and released the return side. Every time we did this, we blew out rust & gook, but we could not break thru. Next step will be the CLR solution thru a pony pump.

 

[Grega]

Your next after that should be trying to find a good replacement core as you will never get it clean enough to produce good heat , probably will start leaking anyway. Unless you take it somewhere and get it rodded out. Would be easier to find a good replacement. Just my 2 cents........

 

[JAD561]

I ordered a core from the local napa store. They are going to try to get me a copper core coil. If they can't find one, i told them to get the napa branded one. If it is an aluminum core, i plan on using insulating board to insulate the core box. Hopefully it will help with the heat loss that other ss members have mentioned when using these types of cores.

 

[Grega]

Dont know about insulating you core box but you should also get a piece of cardboard to cover the grille or get a good grille cover like one from Jatonka. I havnt got one from him yet, but did get some nice seat covers. Even then you might not get the same kind of heat as you would from a gas burner this time in the year unless you keep the RPMS up. Here in Nebraska, the high for tomorrow will be 4 degrees. From what ive seen on the idiot box, the weather up in New York isnt much better. But heres a link to the grille cover. JATONKAM35s HOME ON THE WEB

 

[JAD561]

Thanks for the link. I will look at the grill covers. We did make something out of the insulating board, and we painted it black. You really can't tell it's there, unless you know what to look for. Heater core goes in on saturday.

 

[corelokt]

I took my heater ducts and core out today and insulated around the core with fiberglass I had for packing mufflers. I also closed off the cold air duct. I now have way mucho heat, even with the wrong type thermostat and an aluminum heater core.

 

[JAD561]

How exactly did you insulate ? Inside the heater box ? Also, did you close off the intake on the cowl by the wiper blades ? What is your antifreeze mixture ? I am at 50/50, but heard that it should be 70/30.

 

[OL AG '89]

We dont get the cold that the north gets but its been cold around here for the last week.
I went out this morning to warm up truck and because we had an ice storm last night, I decided to turn the defrost on to do the windshield. I went back out about twenty minutes later and the truck was TOASTY warm!!!
I felt the air coming from the defrost and it was HOT, first time I've ever felt HOT air in the truck.
I switched the control to the heater setting and went back inside.
Came out after another 10 minutes and the air, not very much coming out was WARM??????
I thinking the heater core is fine, just have something??? muddobbers, grunge in the passages.....
Tomorrow when it warms up, should get to the 50's I'm gonna take apart the heater box and see what I find

 

[jamesonsdad]

a fellow cuk-ve owner in town put a aftermarket core in his and he still had no heat he took the old core to north country radiator in queensbury ny and they rebuilt the original and he can bake a cake in his cab....si if no luck try having your stock one redone...

 

[corelokt]

I took the inside duct work and core out. The fiberglass was in a roll and I cut a rectangle to fit in and fill the space where the core is and then cut out the center where the fins of the core were. I also packed fiberglass around the sides of the core. I blocked the flapper "door" that is right there next to and behind the core and did not reconnect the control cable to it. There are two studs that stick into the engine compartment, next to the beginning of the transmission / bell housing tunnel. There is also a bolt going from the engine bay through the fire wall into the heater ducts. From the inside there is a bolt located bat the end of the duct, next to the passenger side fender wall, and one small bolt holding the duct to the defroster vent. Those two studs first mentioned can be very rusty and break easily. Before you start the job, soak those two and then remove the glove box. Don't forget to clamp the heater hoses and go easy on getting the hoses off the nipples of the core, as they crush easy. I also never seize the bolts, studs etc. You may want cold air come summer, or need to take it apart in the future.

 

[JAD561]

Well today was a very interesting day. I purchased a coolant system flush kit, prestone super flush, 4 gallons of 50/50 pre-mix antifreeze, and my son and i went to work. Of course, here in ny, it was a miserable rainy day. We flushed the system twice, and went to work on replacing the heater core. Problems right away. It appears that all of the bolts on the heater core box go thru the firewall. From what we could see, everything facing us from under the dash looked like flat pins that penetrated the fire wall, and passed thru the blower assembly as bolt ends. I was not about to start removing batterys or the dash board to get in closer. I set up the part i made last week for the compressor, and had my son start to blow in air thru the core. We got very little out of it, but when we flushed the system, we did have a lot of rust that came out. My son changed things up a liitle bit, and we hooked up the air in reverse to the core. We blew air in the heater hose that returns to the radiator. Got some wierd milky white gunk and water out of it. We changed things up again, and hooked up a garden hose to the heater core feed side. We got a load of rusty water, followed by a strong clear stream of clean water. We broke thru the core blockage. We reassembled everything, filled the system, "burped" the hoses, and ran for about 10 minutes with the rad cap off. After topping off the coolant, i drove for about 15 minutes, and got heat. It's not as hot as i would like it to be, but it's probably better than what i would have if i put in the aluminum core. I did notice that there is more heat when i use the defroster. I'm stuck with the new aluminum core, and i'll probably put it up on e bay, or maybe in the summer i will have the time and patience to do the change out. Maybe by then i can get a hold of a copper replacement core.

 

[Blood_of_Tyrants]

If you haven't installed the aluminum heater core, maybe you can return it.

 

[OL AG '89]

It got to 60 today so I went after the heater issue. I took the bottom vent off in the vehicle and tried to fish anything out of the passages. I got nothing out of the vent going up to core.
I think the big problem is the "cold air" intake on the vehicle that is always open. I can get all kinds of heat when sitting still, but when I drive around I can feel cool air coming through.
I might flush the heater core in the next couple of weeks, but by then probably wont need the heat until next year.......

 

[Milbikes]

My M1008 gives great heat, regardless of outside temp. I started it up on a 5 degree day, drove it, and it got toasty warm inside. In the past in other trucks I have had, when I got less than hot air out of the defrost or heater, it was usually due to heater/vent doors that didn't open or close fully. This usually happened from the controls not being moved for long periods. Try taking a look up under the dash...but don't get stuck!

 

[JAD561]

I think i will keep the heater core that i bought for a while. It was a special order, so returning it might be a problem. As far as the under dash controls, it looks like everything is working ok, but i plan on disconecting the cable to the blend door to see if i can get it to open further.

 

[Dodgeman1941]

One thing to remember 009 guys, our heater system is designed to handle a vehicle that has inner insulation panels on the interior of the truck, our CUCV's have very few of those. With my boy's 009, even when the front is warm, the back seat is still plenty cold with all that bare steel.