Heater removal

[L5wolvesf]

Hi all,

Before I get myself too deep in it I just want to know how much of a job it is to remove the heater box (where mice and leaves collect). I looks like it is pretty simple, but that can be deceiving. It's a '74 w-100 with A/C.

Thanks,
L

[Megunticook]

I rebuilt the heater system in my '73 W100 this past year, which of course involved pulling the box. It's definitely time consuming, though not hard if you're patient. I did not have a/c, so not sure how that complicates things. You will unfasten the dash on the passenger side and pull it back to make room for the heater box to slide out.

One suggestion I would make: soak the nuts that hold the heater assembly in place (the ones you see in the firewall in the engine compartment) real well in PB Blaster, soak them for several days before you start trying to undo them. I rushed this part of the operation and ended up grinding several off, which chewed things up a bit.

Also--as long as you're taking the time and trouble to do all this, consider replacing the heater core if you're still on the original. Mine had finally sprung a leak on me (the impetus for rebuilding everything). You can get one from rockauto.com for about $60 (as I recall).

You don't want to pull the box, reassemble everything, then find out 6 months later that you need a new core.

Also, since you'll be draining your cooling system anyway, it's a great time to flush that out, change the thermostat, replace hoses, etc. Just a suggestion, maybe you've already done that within the past few years. If it's been more than 3 I'd go ahead and do it.

[Speed Dragon]

A/C might make it a bit tougher. My '73 CC I just took the face off the box to replace the heater core, took about 10 mins. 30 mins for the whole job.

[L5wolvesf]

I rebuilt the heater system in my '73 W100 this past year, which of course involved pulling the box. It's definitely time consuming, though not hard if you're patient. I did not have a/c, so not sure how that complicates things. You will unfasten the dash on the passenger side and pull it back to make room for the heater box to slide out.

This is turning out to ba a bit time consuming with the a/c pieces. Does anyone have a good diagram of the system?

Thanks for the other input I am gonna do the whole thing.

Thanks,
L

[DiverDwnPowrRam]

If you just wish to clean it then why not leave the box in the truck and pull the fan motor from the engine side then stick a vacuum hose inside and be done.