Coolant Question

[Mikes91]

Awhile back I asked about coolant and was told the low-silicate, normal green stuff is OK.

Today I was at NAPA and looking through the coolant. Their list says that diesel engines REQUIRE coolant with nitrites. The coolant they had on the shelf didn't have nitrites.

What the heck are nitrites? SCA??

The bottom line is that any coolant that meets Ford spec ESE-M97B44-A should be OK... I'm just splitting hairs.

Also found that they sell SCA, but want $35 for a box of test strips that expire in 9 months...

Was also wondering how hard the thermostat is to change, and how hard it is to REALLY get the block flushed at home with a garden hose. I've been thinking about taking the truck to a shop, but I never do trust them to do what I've asked and would rather do the job myself. Just a matter of knowing the job is done right... I want to get all the junk out of the system. NAPA sells some cleaner that I plan to use, then drain, then flush. Just not sure how to get ALL the nooks and crannies.

I read an earlier post... "blow out the heater core" and "drain plugs" doesn't mean much to me... I need a dummy's explanation for a non-mechanic. I don't know where the block drains are (I DO know where the oil and tranny drain plugs are!) I don't know where the heater core is or what I have to do to it.

Finally, what is the coolant capacity of a '91 F-350 diesel? My 1991 diesel supplement says 29 quarts, INCLUDING 5 quarts in the overflow bottle. My Chilton manual says 34 quarts for a '91.


Mike

 

[MIDNIGHT RIDER]

29 + 5 = 34

34 divided by 4 = 8-1/2 gallons

The heater core is in the air-box in the cab, behind the glove-box.

The 5/8" heater-hoses go in and out of the heater-core.

Take these hoses loose at the engine and hold the water-hose against the end of one and flush out through the other.

Leave these hoses unhooked and connect a loop of heater-hose between the two outlets on the engine where they came off. so that when you flush the rest of the system, the crud will not settle in the heater-core.

 

[Exekiel69]

The coolant capacity would be 8 gallons I believe.
I just flushed the cooling system on mine, what I used was fleetrite from fleetguard. You can get it at the IH dealer or maybe at the dodge dealer, the one you've seen on napa also have the sca's but is not compatible with the one from fleetguard (for more info on this you may read the cavitation article). Now to remove the heater core you have to remove the glove compartment (no screws just by hand on my 93) you will see a few wires going to a switch that connects to something else (dont remember what that is) you have to unscrew it loose, also disconnect the white switch for more space, then with a socket (1/4?) and extension (8"or more) unscrew and remove the plastic cover you'll see there (might be some 8 screws), it will tough on some to reach specially the ones in the right corner. Once the cover is loose you must take it of its place and lower it, now on top of it there will be a wire connected to a spring that you want to disconnect (it will take some patience to put back latter but it can be done) just remember how it is connected and pry it off, lower the plastic cover and remember to loose the plastic hoses (vacuum?) from the bracket at the bottom. Now you can see the heater core, in order to remove it, loose the clamps on the hoses (on the engine compartment, pass side on the firewall), then first break the hose loose with a channel lock by turning it so it will come out easy by hand latter just turn and pull (watch your fingers and knuckles). When you have it loose push the aluminum hose from the engine compartment and pull from inside the cab (good to have some help there, but you can do it alone) to remove it from the plastic box, you will have to twist it around in order to miss the hoses and lower it. It will not come straight out (not on mine) it will come out by lowering it to the floor just keep twisting and be careful with the fins.
I flushed mine pouring distill water into one hose, shaking it and drain, a few times.

Now to remove the tstat you''ll have to loose the serpentine belt (5/8 or 15mm wrench to loose tensioner) or V belt if you have that year setup, remove the alternator (3 bolts 9/16 I think and don't forget the bracket that holds the coolant hose to it latter) disconnect and remove (don't forget to disconnect the ground first on the batt), if you have the same setup I have you may want to loose the fuel filter bracket (not the filter or the steel hoses, just the bracket so you can twist it out of the way) so you can gain access to the cast iron hose (tstat is inside of it) bolts (1/2 inch one short one long), remove the bolts and hit that hose with a rubber hammer or a piese of wood to breack loose the gascket, remove tstat (notice how it is positioned) remove gascket clean real good with a putty knife, flush (I used distill water for this too) put another tstat, put another gascket (use gascket sealer if you want just be careful not to put any on the lil steel ball inside the cast iron hose) make sure tstat sit's well and put the cast iron hose back and everything else.

btw the block drain bolts are on each side of the block, one is easy above the oil cooler I think and the other one you may want to use a channel lock to breack loose and then loose the rest of the threads by hand, just put a bucket and be fast so you wont take a shower. This last block drain plug you'll find it above the starter, next to the block heater if you have one, next to the oil dipstick at the bottom.

Well I think that is it,is not difficult just give it 1-2 hours for the hole flush job. enjoy :Sly

 

[Mikes91]

29 + 5 = 34

34 divided by 4 = 8-1/2 gallons

The heater core is in the air-box in the cab, behind the glove-box.

The 5/8" heater-hoses go in and out of the heater-core.

Take these hoses loose at the engine and hold the water-hose against the end of one and flush out through the other.

Leave these hoses unhooked and connect a loop of heater-hose between the two outlets on the engine where they came off. so that when you flush the rest of the system, the crud will not settle in the heater-core.

Heheheh. I get the math... one was 34 quarts including 5 qt overflow. The other was 29 quarts including 5 qt overflow... That's where the confusion arises... there's a discrepancy between the two manuals.

Anyhow.. thank you for the heater core info... After reading that, I wonder if Ford/whoever else maintains this stuff EVER does the job right. Kinda makes you wonder what in their service manuals...

It will be interesting to see what comes out of this puppy...

Mike

 

[Mikes91]

Thank you, Ezekiel... sounds like an honest afternoon's work... I wonder how necessary it is to remove the heater core, given that I can flush it out with the hose where it is...

There's a limit to my available time and I may need to do first things first (i.e., heater core assumed OK, thermostat needs replacement, and coolant needs replacement.)


Mike

 

[Mikes91]

Well, nobody nearby carries Fleetrite... so I'm going to run standard NAPA green coolant.

Is Ford's SCA compatible with NAPA's low-silicate coolant? If not, no problem--I'll keep my Ford stuff for the next change.

 

[yARIC008]

As long as the napa antifreeze is just low silicate ethylene glycol you can use whatever SCAs you want with it.

Please, if you are getting ESE-M97B44-A from your factory manual ignore it. It was before Ford knew about cavitation. The standards have changed since then. That specification is for high silicate antifreeze I believe.

Nitrites are simply a different kind of SCA (system cooling addative). They are what napa calls, napakool, or pencool.

These are not compatible with ford's SCA which is a Molybdate/Nitrite mixture which is called VC-8 now.

Use one SCA or the other, not both. So, either Napakool or VC-8 with the low silicate antifreeze. The ratio of SCAs to coolant is one pint per four gallons, so basically two bottles of SCA's for an 8 gallon cooling system. You must check the ford stuff with Fleetguard test strips and the napa stuff with preferably the napa stuff. You can use fleetguard strips to test the napa stuff but you'll just be wasting money as the napa test strips are cheaper. You can find fleetguard strips online for pretty cheap. Like a 4 pack for 5-10 bucks.

Don't really know which one is better, Napa or Ford, but if i had to guess I'd say the Ford one because it uses two different SCAs together, the napa stuff only one. I've heard that the Molybdate/Nitrite has a synergyzing effect which gives it greater protection than the sum of it's parts can.

If you haven't already, read my cavitation article. It answers all of these questions.

Hope that helps.

 

[Mikes91]

Thanks, Yaric. I was in a hurry to get to school so didn't catch the info I needed quickly enough from the Cavitation article. Thank you for putting the info I needed here.

Mike