Coolant flow question
 

So can someone tell me how the coolant flows from the engine to the heater core and back in an 84 300D? I'm helping a friend with some repairs and we were discussing it a bit. It looks like the flow would be like this....

1. Out of the water pump, then out through the hose by the alternator.

2. Through that hose to the aux heater assembly, then through another hose up to the monovalve on the firewall and into the heater core.

3. Then through the heater core, and out the hose to the top of the head on the engine.

4. Through the engine back to the water pump where the circuit starts all over again.

Am I correct, or is the flow reversed from how I discussed (out flow at the top of the head instead of inflow)

Heater flow is: 4-3-2-1!

Hot water is supplied from the head, returns to water pump.

Ok, so basically I had it backwards the first time? How about this.

1 . Hot coolant out the hose at the top of the head and into the heater core.

2. Through and out the heater core, through the monovalve and through the hose to the aux heater assembly.

3. Through the aux heater assembly and to the hose leading back into the engine by the alternator.

4. Into the engine and to the water pump where it all starts the circuit again

Correct??

The cooling circuit is shown in the shop manual:

How Glysantin® coolants work ǀ Glysantin®

Play the video in the link. Not sure if this is what you mean.

Thank you all.....Got the answer to my questions!

Ok, another question comes to mind. I asked this before in another forum section, but did not get an answer...... Does anyone know the size of the heater hoses? I'm thinking 5/8" or 3/4. Going to do some work soon and would like to know the size (and no, cutting a piece of hose off and taking it to the auto parts store is not an option!)

Thanks,

Glenn

Are you getting another hose? If so, just order the specific hose from online. No measuring required. Just make sure it looks the same and you can also look it up by part number to be sure you are ordering the correct part.

No, I want to install a "T" fitting, so I need to know the size of the hose. I could disconnect it and measure, but I don't want to open the system up until I need to.