130 Engine Heater/Radiator issues

[pkzip]

I pulled the heater box out of the car months ago and plan on refilling the radiator sometime in the next few weeks. In lieu of the heater (which I plan on NOT installing until after I have the wood refinished - more head room for the reinstall), I plan on using heater hose to reroute the water that would normally go through the heater. However I have a number of questions.

1) Although I pulled the box over the summer, I seem to recall that there were three not two water outlets into the engine re. the heater as there are three outlets in the heater box (two above and one below). If this is true, how do I reroute the third outlet and to where?

2) I will need to probably replace the thermostat upon refilling the radiator. DO I do this now or wait until after I replace the heater box? How do I replace the thermostat without dealing with the horror stories I have read on this list and elsewhere re. sheared off bolts, stripped bolts and holes, etc.

3) Flushing/Burping the system - I read the archives. Any other tips?

Thanks in advance for all the help.

P. Kaufman

[240 Ed]

I think that your heater has the same set up as mine, (mine being a 68 250S). There are two valves for the heater because each side of the passenger compartment has a control for heat. This would account for two of the hoses, and the third would be FROM the engine. As to the return hose, I dunno where it is, look around. Just hook them together to close the loop.

[Aaron]

Just wait on replacing the t-stat until after you refit the heater box. Fill the upper radiator hose with coolant (also add a bottle of Red Line Water Wetter), connect the hose and fill the radiator up. A good thing to do is to disconnect the heater hoses at the firewall and wait for coolant to come out of them before starting the engine. It helps to purge the air. When you start the car, you'll probably have an air pocket (M130 is notorious). When the temp needle begins to climb rapidly, shut the engine down and let the car sit for 20 minutes or so. Carefully remove radiator cap and check level. Refit cap and run engine again with heater at full blast. Keep repeating this process if there is still an air pocket.

[pkzip]

Thanks Aaron. I will follow your suggestion except for leaving the heater at full blast as there will be no heater (at least the first time) to leave at full blast. Instead the heater hose bypass from the box will have unfettered flow. I assume that would do the same thing you had in mind (other than taking herat away from the engine) as leaving the heater on full blast (i.e., valves open all the way). Thanks again for the advice. Peter

[pkzip]

Aaron - by the way, am I right about the outlets from the engine to the heater? I seem to remember there being 3. One on the forward right (passenger) side; one on the rear driver's side and the last on the lower rear driver's side. It is this last one that concerns me (that is, if it exists on the engine or just in my memory). Please let me know what you think. Thanks. Peter