87 Avanti heater hose routing

[jwikstro]

I need help understand the heater hose routing.

On my car there are a cable operated non-bypass open heater valve in the pressure hose on the right side of the engine before the heater. And a red hose coming from the backside of the engine going to a T-piece on the return hose on the left side of the engine see pic. When looking on pics of other cars I see routings where there are a T-piece on the pressure hose and a hose going to the engine. And on some there seems to be no T-piece an hose going to the engine. I have looked at pics from Chevy forums and seen non with the T-piece and hose to engine.

Which routing are correct ? Do I really need that that extra T-piece and hose to engine?

/JW

[wopony12]

I have 2 hoses on my 87. One going to heater and one coming from heater. On the one going to the heater is where the temp. control valve is. On the return hose I had to put a shut off valve, otherwise the water flows back to the heater with hot water and air wouldn't blow cold.

Gary

[jwikstro]

Gary,

This variant I was not aware of. On mine there are a shut of valve after the temp control valve. There are an arrow that indicate water flow direction from the heater on the temp control valve.

When inspecting the temp control valve there are a grove that lets water pas on the outlet side, probably to drain the valve when closing. When blowing from outlet side there are a leak, when blowing from inlet side, no leak.

And I thought that was way the shut of valve as the temp control valve seems to be turned backwards.......Or do I got it totally wrong and mixed inlet outlet of heater hoses.

/JW

[wopony12]

Hard to see where hoses go from pictures. My inlet is on right side of car with temp control valve and outlet runs on left side. Not sure where your t hoses are going to. Will recheck my hoses better for you.

[wopony12]

I have inlet on right side of car goes from manifold to heater with temp control valve in line. Outlet goes from heater to water pump. I have no T on either line. I can not tell which way is correct. where do your hoses start and end. My hoses could be reversed. The hose from the water pump goes to the left side (drivers).

[wopony12]

From looking at my car and on forums the routing is from manifold to left side of heater (passenger side) with control valve in line and right side (driver's side) goes to water pump. Did not read or see anything about Tee. Hope I helped.

[jwikstro]

The routing is the same on my car, but i have an additional hose coming from a spigot on the engine block close by the distributor (se pic) going to the T-piece on the return hose on the driver side.

Any one who know way there are differences between cars from the same model year?

/JW