Heater Core Installation '80-96
Case is shown front-down. '87-early '88 use no vacuum motors inside the cab.
The boss just above the PLENUM TO COWL SEAL arrow is the drain duct.
To R&R the heater core:
1) with the engine cool, remove & replace the radiator cap to relieve any pressure.
2) disconnect the hoses from the heater core nipples, near the R hood hinge, and position them up so they don't drain.
3) remove the glove box.
- '80-86: remove 5 phillips screws and pull the box out;
- '87-96: fold the glove box down & remove it from its hinge;
- '87-96 F-series: remove the RABS module for access.
4) remove ~7 hex-head screws from the heater core cover, and remove the cover.
5) being careful not to damage the foam seal, remove the heater core.
Heater Hose Routing:
![](http://www.supermotors.net/getfile/512250/thumbnail/heaterhose49l.jpg)
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![](http://www.supermotors.net/getfile/512251/thumbnail/heaterhose50l.jpg)
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![](http://www.supermotors.net/getfile/512252/thumbnail/heaterhose58l.jpg)
See also:
How the cooling system works![](https://www.supermotors.net/getfile/1142745/thumbnail/coolantneglect.jpg)
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![](http://www.supermotors.net/getfile/883864/thumbnail/acboxin.jpg)
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![](http://www.supermotors.net/getfile/743849/thumbnail/heatercore.jpg)
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![](http://www.supermotors.net/getfile/723836/thumbnail/tsb880910heaterbaffle.jpg)
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![](http://www.supermotors.net/getfile/72422/thumbnail/ventilation8086.jpg)
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