I Am Getting My Radiator Flushed & Refilled Tues. Or Wed. I Have One Pint Of Napa Kool. Label Says Add 1 Pint To Every 4 Gallons Of Collant As An Initial Charge. How Many Gallons Of Coolant Will It Take On My 7.3l[ A/c ]? Should I Add That Much Napa Kool? Also, Should I Replace The Thermostate, & Have The Fan Clutch Checked? Any Thing I Should Have Checked While It Is In The Shop? What Is The Best Type Of Coolant To Use? Sorry For All The Questions, I Love This Truck, Just S_ _ K As A Mechanic. Bob.

 

According to AutoZone, you need 3.5 gallons of antifreeze to do a 50/50 mix. I prefer a 70/30 mix myself, but that's just me.

I would replace the thermostat, and also make sure the hoses aren't spongy or swollen. Having the fan clutch checked couldn't hurt.

 

Have you got the test strips? Check your ph and nitride levels after filling.

 

Don't forget the overflow reservior, I think 32 liters is the full system. Only use distilled or deionozed water with the coolant. NAPA or IH have the right test strips usually in single packs. Testing for..... Nitite, PH and freeze point.

Have you considered puting lower block drains in while your at it........ this is from my friend BAJA now OKIE Gringo

BajaGringo Block Drains

The block drains are just 1/4"npt pet*****, available in the "HELP" section at the auto parts store. You need a 9/16" crowfoot socket that fits on a socket extension to reach in to tighten them (There's no room for a reg open end wrench). Then, cut up an old spark plug socket to fit over the petcock to loosen/tighten. Once they are loose, slip the 3/8" rubber hose over the end of the petcock and continue loosening the petcock (with the other end of hose in bucket). Intstalling these is still messy and a bit of a hassle, but NEXT TIME it'll be a lot less messy and a lot easier. Smear 'em with anti-seize to make sure they turn 'next time'. I've already had to use mine because when I had the radiator 'rodded' they didn't have the right kind of antifreeze, and I was 200 miles from home. So I needed to re-flush the system and re-DCA it. This makes saving/reusing the expensive DCAs/antifreeze possible if you use CLEAN BUCKETS. I bought a special funnel that snaps into the radiator fill, and use a metal spray paint funnel/filter/screen just to make sure nothing too big gets back in there. Yeah, I'm a little '**** retentive', that's probably why my eyes are brown. BajaGringo

 

With a totally drained system 8 gallons ( 4 gallons antifreeze and 4 gallons water for a 50/50 mix) is enough total coolant to fill the block and the coolant resivoir.

I now use NAPA Fleetpride precharged antifreeze. It is available in the 50/50 prediluted or the full strength version. It is purple in color.

The block drains are a good idea, saves you from a face full of antifreeze if you have to change block heaters or oil coolers. Also it makes it much easier flush the system since you can drain it completely.

 

good advice. thank you all. bob.

 

Ensure you use the right Tstat......
CAUTION:
The specified/required thermostat does not contain an internal bypass, since the bypass is located in the cylinder block. Whenever the thermostat is replaced, it is mandatory that only Motorcraft E5TZ-8575-C or Navistar 1807974C94 thermostat be installed.

CAUTION:
Do not attempt to repair any thermostat. It should be replaced if it is not operating properly.

Check the new thermostat before installing it for correct opening temperature. Before suspending in boiling water, with a flashlight check where the rubber and the flat metal flange meet for bad seal. Tstat should start to opening barely at 180-192f, fully open 200-212f, allow to cool and check for rubber seal again.

Removal: Disconnect batteries, drain 4+ gals A/F, remove: as required, fan belt, alternator set aside, alt bracket, remove filter support from fuel filter then e/block. Disconnect upper rad hose at rad, remove tstat bolts and housing. Clean both faces, depression and holes in block, ensure check ball in goosekneck is clean, free and rattles "do not remove".
Installation is reverse proceedure, I do not use sealant on gaskets and faces. REMEMBER the tstat pellet(copper end) goes into the block. I do use a "very small amount" of sealant on the edge of the tstat face when installing into the recess, now go for coffee, allow sealant to setup, this has saved me from tstat slippage when the gasket and goosekneck are installed. Replace all items in reverse order......

Manifold bolt torque......... 20ftlbs