Heater Hoses

[ingramlee]

I'm getting ready to replace the supply and return hoses to the heater core. All other engine bay hoses were done a year ago.Will the car pee coolant all over the place if I don't drain the coolant first? I'm not sure why I flushed the coolant a few weeks ago and not wait to do the hoses also. Oh well... coolant is cheap. I'm also concerned a little because the new hoses look a bit smaller than the old ones. hopefully this is because the older ones are old and somewhat swollen. Also, hope I don't break the old fragile heater valve support bracket while trying to push on the new hose. Any tips to remove and/or install the new hoses?I really don't want to remove the heater completely.

[Buckeye]

I would cut old hoses in axial direction using sharp razor blade. Use dish soap on new hose ID and sand paper on OD of connectors before installing new ones. 

[Mike Self]

It wouldn't hurt to drain the coolant down a bit.  When you remove the hoses the coolant will run into the heater plenum chamber; then you'll be smelling coolant for some weeks afterward whenever you open the fresh air/heater ducts.  

 

+1 with Buckeye on cutting that itty bitty hose that connects the heater core with the water valve.  Mine was 26 years old when I discovered it had never been replaced, and was hard as a rock (but not leaking!).  Had to saw it off with a small hacksaw.  

 

And when you're installing the new long hoses, it's helpful to lubricate the outside of the hoses (as well as the inner ends) so they'll slip through their grommets easily.  

 

mike

[ingramlee]

13 minutes ago, mike said:

It wouldn't hurt to drain the coolant down a bit.  When you remove the hoses the coolant will run into the heater plenum chamber; then you'll be smelling coolant for some weeks afterward whenever you open the fresh air/heater ducts.  

 

+1 with Buckeye on cutting that itty bitty hose that connects the heater core with the water valve.  Mine was 26 years old when I discovered it had never been replaced, and was hard as a rock (but not leaking!).  Had to saw it off with a small hacksaw.  

 

And when you're installing the new long hoses, it's helpful to lubricate the outside of the hoses (as well as the inner ends) so they'll slip through their grommets easily.  

 

mike

Thanks Mike... Trying to get these little things done before Mid-America. Looking forward to the caravan again this year.

[Guy Cocquyt]

One additional comment:

Because the heater core is higher than the engine, you may lose the "prime" on the system when you remove the connecting hoses and you might have problems getting the coolant to flow back up and through the heater core due to air-locking.  

 

I had this problem when I installed a new heater core. What I did was loosen the exiting hose's lower clamp on the driver's side at the back of the engine, and with the engine running, "bled" the heater core until I had a good volume of fluid coming through and then tightened up the clamp.  You will need a catch pan and it would help to have someone else to start and shut the engine down during this process. I did it solo and it went OK but I lost a lot of fluid.

[jgerock]

This is how much old coolant was in my early 2002 heater box when I removed it from the 69.  Engine and radiator had already been removed.