Would this work---temporary heater core hose routing?

[In The Ten Ring]

I want to start the truck this weekend, to run the engine. It has a new heater core, new radiator, and I have been finding the right hoses. I won't be driving it this winter, so no reason to get fluid into the new heater core. Could I just run a short hose from the water pump side to the return, just a short loop, leaving out the heater core?

[truckster]

Sure. Some people don't run heaters at all.

[In The Ten Ring]

Originally Posted by truckster

Sure. Some people don't run heaters at all.

Great! I had thought about putting valves into each heater hose but they tend to be heavy and I also thought about two short hoses and plugs.....but a loop can be used over and not cut.

[dflarsen77]

I think they're different sizes, one is 3/4, one is 5/8. Can't remember which is which, and my truck is in pieces, but I know they were different in mine because the heater core pipes are different sizes. Although mine is an AC truck and the heater core is different than a non-AC truck heater core.

['68OrangeSunshine]

The bigger diameter is on top.

[In The Ten Ring]

Originally Posted by dflarsen77

I think they're different sizes, one is 3/4, one is 5/8. Can't remember which is which, and my truck is in pieces, but I know they were different in mine because the heater core pipes are different sizes. Although mine is an AC truck and the heater core is different than a non-AC truck heater core.

I love you guys but sometimes I get the impression people don't read the opening posts very carefully. I will not be driving the truck, I just want to start the engine.

*Truck is actually up on blocks, there is too much to do, this is only to get anti freeze back into the washed-out water jacket of the engine.

I have the heater core in as advised on here, bigger opening on top, and I know they switch when hooked up to the engine (upper to lower, lower to upper). I have had the problem of the 5/8 inch hose fitting over the flare of the upper engine side opening. Fortunately, the guy at Advance Auto suggested and sold me a 3/4 inch to 5/8 inch reducer coupling. I can use that and make things work pretty well I think.

I just want to start the engine.....the truck won't be driven, it won't leave the garage before spring at the earliest.

[Steeveedee]

You can stretch the 5/8" hose over the 3/4" nipple as a temporary measure, to get the coolant to circulate. Note that you can also buy caps to put on the fittings instead of having a hose recirculate the coolant. Or just put plugs in where the hose fittings are now.

[In The Ten Ring]

Originally Posted by Steeveedee

You can stretch the 5/8" hose over the 3/4" nipple as a temporary measure, to get the coolant to circulate. Note that you can also buy caps to put on the fittings instead of having a hose recirculate the coolant. Or just put plugs in where the hose fittings are now.

I tried to push that 5/8 inch hose over that flare and it just wasn't going on far enough to suit me.

Thanks for the suggestion of plugs, I bought two yesterday but now I've decided to just loop the 3/4 inch line from water pump to return. That will get my water jacket full and I won't have to cut off any short pieces.

I'll test fit all hoses now so I can be ahead of that task come spring.

[hjewell2]

Originally Posted by In The Ten Ring

I want to start the truck this weekend, to run the engine. It has a new heater core, new radiator, and I have been finding the right hoses. I won't be driving it this winter, so no reason to get fluid into the new heater core. Could I just run a short hose from the water pump side to the return, just a short loop, leaving out the heater core?

on a SBC you can plug the intake and the water pump without having to hook the hoses from heater core to the pump or intake. on the water pump there is a bypass built in on the left side of the pump where it is bolted to the block.

[In The Ten Ring]

I got it! Sorry, no pics.

I was able to force the 3/4 inch hose over that big flare. Now the heater hoses are just one hose that makes a loop.