[pairodice]

It is really difficult to see where the water is streaming from - it looks like it is coming from the area above the two ping tanks in the front of the coach. Are there hoses for the heater core under the coach (I would assume not since there are four hose connections on the heater core.
Next question: IF the heater core is bad then can should I connect the 2 red hoses together (I would assume the red hoses represent HOT) and then the 2 black hoses together?

[Richard]

Ok,

There are two sets of hoses. One set goes forward to the heater core. The second set goes to the AH.

Identify which set is which.Close the supply line and return line to the dash. This is much easier than bypassing the heater core.

Fill the coach with coolant. And be done with it.

[whited44]

Thanks for the clarifying info.

Then the heater core is likely your culprit. Open your generator bay and inspect the ceiling. White paper towels are your friend in this case for finding coolant leaks. The core is directly above the gen bay, and since water/coolant generally obeys the laws of gravity then what you reported makes sense. Yours would not be the first core to fail.

Here comes the good news/bad news. You can keep those valves shut and still use the coach. Obviously you will lose dash heat AND the engine coolant circulation through the AH. If you can figure out which loop is for the AH you could open those. If I knew which valve was which I would say. The bad news is I think replacing the heater core is going to be a CHORE. I would try to get some advice from Newell.

Hi Richard. I think my heater core or a hose at the heater core is leaking.  I have 3 valves that I can see back at the engine. 
2 on the side of the motor on the drivers side and one coming out of the water pump. I can’t find a fourth one.  
If it’s leaking can I close all 3 valves??  It’s a very small drip. Any advise would be helpful

[Richard]

Yes you can close all 3 (4). You will not have dash heat. You will not heat the aquahot tank with the engine while driving, nor can you preheat the engine with the aquahot.

[[email protected]]

Thanks for the clarifying info.

Then the heater core is likely your culprit. Open your generator bay and inspect the ceiling. White paper towels are your friend in this case for finding coolant leaks. The core is directly above the gen bay, and since water/coolant generally obeys the laws of gravity then what you reported makes sense. Yours would not be the first core to fail.

Here comes the good news/bad news. You can keep those valves shut and still use the coach. Obviously you will lose dash heat AND the engine coolant circulation through the AH. If you can figure out which loop is for the AH you could open those. If I knew which valve was which I would say. The bad news is I think replacing the heater core is going to be a CHORE. I would try to get some advice from Newell.

Hi Richard. I think my heater core or a hose at the heater core is leaking.  I have 3 valves that I can see back at the engine. 
2 on the side of the motor on the drivers side and one coming out of the water pump. I can’t find a fourth one.  
If it’s leaking can I close all 3 valves??  It’s a very small drip. Any advise would be helpful

Look up high on the driver side of the engine near the valve cover that is where my 4th valve was, it’s hard to see.

[whited44]

Thanks for the clarifying info.

Then the heater core is likely your culprit. Open your generator bay and inspect the ceiling. White paper towels are your friend in this case for finding coolant leaks. The core is directly above the gen bay, and since water/coolant generally obeys the laws of gravity then what you reported makes sense. Yours would not be the first core to fail.

Here comes the good news/bad news. You can keep those valves shut and still use the coach. Obviously you will lose dash heat AND the engine coolant circulation through the AH. If you can figure out which loop is for the AH you could open those. If I knew which valve was which I would say. The bad news is I think replacing the heater core is going to be a CHORE. I would try to get some advice from Newell.

Hi Richard. I think my heater core or a hose at the heater core is leaking.  I have 3 valves that I can see back at the engine. 
2 on the side of the motor on the drivers side and one coming out of the water pump. I can’t find a fourth one.  
If it’s leaking can I close all 3 valves??  It’s a very small drip. Any advise would be helpful

Look up high on the driver side of the engine near the valve cover that is where my 4th valve was, it’s hard to see.

I found the 4th valve. Confirmed the heater core is leaking.  Now to figure out what valves go to what..  I’d like to keep the aqua hot loop and shut down the heater core loop

[whited44]

Just thinkin outloud here.. 

I found all 4 valves.  I ran the Aquahot preheat today to try to isolate the Aquahot loop to see what valves warmed up the fastest with no real concrete outcome.  Valves 2,3,4 warmed up and 1 was cold.  

From what I’ve read about semi’s with 60 series motors is that the inlet to the heater core is up my the thermostat (valve 2) and the return is on the suction side of the back of the water pump (valve 1).

Valves 3 is almost impossible to get to. I need longer arms.  Once they go over the transmission I can’t see where they go.  

I’m going to close valve 1 and 2 and fire it up to see if the aqua hot still heats up.  

Let me know what you guys are thinkin

[[email protected]]

Just thinkin outloud here.. 

I found all 4 valves.  I ran the Aquahot preheat today to try to isolate the Aquahot loop to see what valves warmed up the fastest with no real concrete outcome.  Valves 2,3,4 warmed up and 1 was cold.  

From what I’ve read about semi’s with 60 series motors is that the inlet to the heater core is up my the thermostat (valve 2) and the return is on the suction side of the back of the water pump (valve 1).

Valves 3 is almost impossible to get to. I need longer arms.  Once they go over the transmission I can’t see where they go.  

I’m going to close valve 1 and 2 and fire it up to see if the aqua hot still heats up.  

Let me know what you guys are thinkin

Sorry Dennis, somehow I missed this post. 

So I will have to go look but I am thinking that valves 3 & 4 are on the pressure or supply side and that valves 1 & 2 are returns. But it’s hard to see in the photo. 

Here is my reasoning and understanding of how the S60 coolant flows:
Coolant leaves the pump (output flow) and goes into the oil cooler, thats the housing just above the oil filters that they attach to. From there it goes into the block, flows up to the head at the thermostat housing. At the thermostat you have two paths, a bypass right back to the water pump the other path is to the radiator (when the thermostat opens). Radiator then has a return line to the water pump. 

So this is why I am thinking that valves 3 & 4 are on the output side of the water pump because it appears they are coming off the oil cooler. That would then leave the other valves 1 & 2 as returns. 

I will try to remember to look at mine this afternoon when I get home from work and see if I can see where those valves are connected.

[whited44]

Just thinkin outloud here.. 

I found all 4 valves.  I ran the Aquahot preheat today to try to isolate the Aquahot loop to see what valves warmed up the fastest with no real concrete outcome.  Valves 2,3,4 warmed up and 1 was cold.  

From what I’ve read about semi’s with 60 series motors is that the inlet to the heater core is up my the thermostat (valve 2) and the return is on the suction side of the back of the water pump (valve 1).

Valves 3 is almost impossible to get to. I need longer arms.  Once they go over the transmission I can’t see where they go.  

I’m going to close valve 1 and 2 and fire it up to see if the aqua hot still heats up.  

Let me know what you guys are thinkin

Sorry Dennis, somehow I missed this post. 

So I will have to go look but I am thinking that valves 3 & 4 are on the pressure or supply side and that valves 1 & 2 are returns. But it’s hard to see in the photo. 

Here is my reasoning and understanding of how the S60 coolant flows:
Coolant leaves the pump (output flow) and goes into the oil cooler, thats the housing just above the oil filters that they attach to. From there it goes into the block, flows up to the head at the thermostat housing. At the thermostat you have two paths, a bypass right back to the water pump the other path is to the radiator (when the thermostat opens). Radiator then has a return line to the water pump. 

So this is why I am thinking that valves 3 & 4 are on the output side of the water pump because it appears they are coming off the oil cooler. That would then leave the other valves 1 & 2 as returns. 

I will try to remember to look at mine this afternoon when I get home from work and see if I can see where those valves are connected.

That does make sense. Of course valve 2 is seized up..  I tried to close it with no luck.  If 3 and 4 are the inlets then if I can get those closed it would help with my heater core leak yes??  Or does the return side also need closed??

[Richard]

Both inlet and return.