Heater hose routing

[G.M.H]

I am switching to tbi injection on my truck. The heater hoses used to connect to the waterpump, and the front of the intake manifold. The tbi manifold has the outlet at the rear of the manifold. I am keeping the old style-normal rotation waterpump and I have no fitting on the rad tank. Can I just move the one hose from the front to the rear? Is the waterpump fitting an intake or discharge?

 

[LongIslander26]

Water pump

The water pump fitting should be a discharge, and you should be able to just move the other hose to the fitting on the rear. You can always double check by filling the coolant system with just water, and leave the hose for the rear fitting off, start the engine, and make sure which direction the water flows, then just drain the water out, and add coolant after that.

 

[dyeager535]

Water pump fitting on my motor was an inlet. Manifold is pressurized by the water pump, coolant is not pushed out the pump fitting.

TBI pumps are all reverse rotation, correct? They may actually be an outlet because of that, but since I've got the older pump, I can only comment on how the "standard" rotation pumps work.

 

[LongIslander26]

Water pump

Either way it should stiil work. Reverse rotation is on serp belt systems. The water still flows the same way, the impeller is just reversed because the serp belt spins the pump counter-clockwise.

 

[dyeager535]

I don't think that's correct. Reverse the impeller on the shaft, one direction the water is being forced toward the fitting (counterclockwise) and if spun clockwise, the angle of the fitting would likely create slight suction. Mine comes out at a bit less than a 45* angle towards the passenger side top of truck. If the impeller turns clockwise, how is that going to force unpressurized water into the fitting?

If it's the same both ways, (like mine) then sure, his idea would work. The manifold is pressurized and would force fluid into the water pump.

I had a complete (well, it never warmed up much) lack of heat and obvious lack of flow into the radiator tank by hooking one end up to the water pump, and the other up to the radiator. Switched fitting from pump to intake, problem solved.

 

[R72K5]

well either way one hose is smaller than the other and one nipple is smaller than other, you cant get it wrong, they should still be 5/8" and 3/4" 87-up too
on the old ones it was 3/4" on waterpump (or radiator tank) one and 5/8" on intake manifold one


good luck

 

[G.M.H]

You are correct. After looking at it again, it makes sense. Hot water from the manifold goes through the heater core and back to the pump. The pump only sucks in cooler water from the rad & heater core. Also the hose inlet is not inline with the impeller like the discharges, but offset like the rad intake.Thanks for the input.