Heater Fittings

[Varyag]

I am installing my heater tonight and I was wondering if anyone could tell me the size and thread of the fittings you have to install in the side of the water pump and the water manifold. I need to pick it up tonight but left the fittings at home this morning...

Also, about how much hose do you think you need to go from the front of the block to about 2.5 ft into the cab?

 

[randini]

I would like to know also. Anyone help?

 

[DUG]

As it happens I JUST bought mine a few hours ago. They are 3/4 inch pipe thread. We used an elbow to clear the dual alts and then installed a couple ball valves. Rain is coming so I won't get the actual hoses installed for a couple days, but everything is ready.

Hope this helps.

 

[Tinwoodsman]

I could not pull up the photos.

 

[randini]

Thanks guys. I acn use galvanized plumbing fittings, Right? I have the Heater and I am now off to the hardware store!!

 

[Varyag]

the top fitting is a 1/2 npt and the one off the water pump is 3/4 NPT. Dug got me the sizes just before I went out so I have him to thank for it.

Took about 16 ft total of heater hose to go from the fittings to the far right (passenger) hand side of the cab running the hoses though the punch-out on that side of the cab.

We took it out today and had a VERY toasty deuce ride for about and hour and a half.

 

[DUG]

Both my fittings were the same size. Are you sure you connected to the correct spot up top?

I used nine feet of heater hose but I went to the top of the motor and through the firewall in the center since it was the closest to the heater connections. Went for a small ride so the truck only got to 160 degrees. It's nice having 12 volts for the slower speed.

 

[Varyag]

I made a baffle for the heater to push it out to the sides so instead of dealing with hot hurricane force winds in the passenger seat, our pant legs were just flapping. When I get my 12 volt wired up I think I will do that too.

 

[randini]

My water pump connection was 3/4 also. The upper connection was 1/2.

 

[AN/ARC186]

I would use brass fittings instead of galvanized steel. also make sure to use Teflon tape or pipe thread sealant paste on all the fittings.

 

[shenkmen]

Upper is 1/2 NPT and the lower is 3/4 NPT. I used brass fittings and teflon. No leaks.

 

[DUG]

Wow, maybe I'm not connected to the correct spot. I need to go look.

 

[shenkmen]

Look in T M 9-2320-361-20 and go to page 3-102 "Personnel Heater Inlet and Outlet Hose Replacement".

See the attached as well.

 

[DUG]

Yeah I read that and saw a high res pic and STILL got it wrong. Headed out to buy a new elbow now. Thanks guys.

 

[DUG]

Had to pull the upper alt to remove the wrong fitting. Using a short hose and a valve allowed me to safely drain the anti freeze into a couple jugs. We had to heat the 1/2 plug up to get it out, but it finally gave in. Reinstalled the alt and then the new elbow. On the test start we heard a terrible noise and quickly shut down. Sounded like the fan hitting on something. A careful inspection showed small nicks on the 24 volt alt's fan. Turns out in the dark I incorrectly installed a support bracket from the 12 volt alt that allowed it to just barely hit.

All better now, but I had some puckering going on. We will test the heater with the properly installed hose Monday. Thanks again for the heads up that I was AFU.

 

[srodocker]

hahahaha good thing you caught it dug! im so glad an/arc186 helped me on my install. drilling through the firewall sucked thought. it was rain/snow mix when i was sitting on my engine doing it hahah

 

[OldDominionIron2]

I had to run my engine for a while to heat it up to remove the upper plug as well. I went to a local hydraulic store and spent about $20 on bulkhead fittings, hose fittings and a 90 and a 45 degree elbow. I'll post pics later tonight when I get home. I was nervous about running hoses through the firewall and them rubbing and wearing a hole in the hose. Makes for a much cleaner install, I think.

 

[OldDominionIron2]

pictures as promised.

 

[Speddmon]

Now you guys are making me want to go check my installation to be sure. Both of my fittings were the same size...I believe 1/2". My heater works just fine and the truck get's up to temp just fine, so I don't think they are bypassing the t-stat line the article suggests. I'm almost 100% that they are in the correct locations, because I looked and researched several times before I installed them.

 

[Speddmon]

Ha Ha...Little Edit. I just reviewed some pics I took when I put in the heater last year. The valves were already in my truck, and the hoses had been removed and the ends crimped over because the valves were obviously bad. There was already a 3/4" to 1/2" bushing in the lower port, so that's why mine were the same size. But in looking at the PS mag article again, the GI that installed the original heater did put the top one in the wrong place, so I just replaced the old valve with a new valve in the wrong spot as well.

I guess it was one of those thing where your brain sees what it wants to see...I saw the article and pictures of peoples installs before, and then I saw the valves on my truck, and my mind said..."yup, they're in the right locations" . I guess I get to change that top one when the weather get's a little better.