I have an early 99 f350 7.3 and can't figure out what coolant to use. The biggest thing is that it has had a replacement engine put it from Ford back in 02.. The early and late 99's both had different coolants correct?

From searching i know you can't use elc in the early 99 but I don't know what you can use.. And when Ford put in the remanufactured engine in 02 did they put in the updated engine?.... Is there a coolant that is compatible with both engines?

Also, I know with my 6.0 I ran a flush. Should I do that here too? Any additives I need to put in?

I also posted in the superduty forum but think it belongs here instead

 

Tough question, early '99 you can only use the green and have to add SCA's to it. But what/ how the reman was made that's the million dollar question. sorry I can't be more help. You can just put the green back in it with the additives and be safe

 

What color stuff did Ford put in it when they installed the new motor? I'd just stick with that and flush it a little. The green is good anywhere but the orange will eat things not made for it. If you change coolants it would be more important to flush it better.

 

Ok thanks guys. I know the guy who used to own it so I know the engine was put in at around 90k miles after an employee fill 3/4 of a tank of gas on top of a 1/4 tank of diesel towing a trailer. Don't know if he ever flushed it but the coolant is green right now. Truck has 180k on it.

Should I use a chemical flush?

 

What green coolant and what SCA should I use? Anyone have an Amazon link so I know I'm buying the right stuff?

 

I would do Gooch's flush and if you choose to use the glycol ( usually green) coolant they have it precharged with SCA's at tractor supply. Get the undiluted kind and use four full gallons then top off with distilled water.
Personally I would look on the drivers valve cover and find the manufacture date. If it is post 12/31/98 I would convert to ELC. If the date is before that then either they reused your old covers or you still have an early 99. That being the case stick with the glycol base. If you do use the green then you will need to add SCA's right away. The stuff at tractor supply is pink but it is still the glycol base and not the Organic acid base like the ELC is.

 

Isn't the reason the older motors only use "green" coolant is because the seals/gaskets/cups will leak with ELC?

I remember reading that, but want to confirm.

If the above is true, and you've replaced your cups, oil cooler orings, water pump/gasket, then wouldn't you be ok to use ELC?

Unless International changes the carbon steel formula, I struggle to see what limits using ELC.

Can someone add some clarity and links to useful discussion data?

 

You are correct on the non compatibility of the seals and the sealant used on the cups. If you do a search for Gooch's flush procedures he has a VERY extensive write up on the topic.
I am on my phone and would add the link but it might take until tomorrow to find it.

 

I have always advocated not to catagorize coolant by color, but in this instance, when you refer to an orange coolant, did you actually mean to reference the Ford "Gold" (Zerex G-05) coolant? Because the Ford "Orange" should never ever be used for our trucks.

Excellent advice, reps!

As Bill stated, that is correct.

Gooch's Coolant Flush Procedure and In-Depth Coolant Information - FTE

Here's the coolant info thread I put together using info from Gooch as well as sourced by me from research on the 'net.

Stewart

 

I found the specific information. Seems once you replace several items that fail over time, you would be good for ELC. The front cover seal is the only seal I haven't replaced that comes in contact with coolant.

https://www.ford-trucks.com/forums/9...ml#post8935612

 

Yeah, that's the same thread I linked you to in my above post.

Stewart

 

Thank you, I do appreciate that information and it supports my own personal KISS (keep it simple, stupid) methodology. I was completely unaware of the Ford "Orange" but would never encounter it given my MO of sticking to the green stuff that I have known all my life.

 

Pick a coolant meeting ASTM4985 (IIRC) and add SCA's if it doesn't come pre-charged. Pick up some test strips and I would buy them from a truck or heavy equipment shop. Test strips do expire and SCAs settles over time so buying fresh inventory is always a good idea. Dip a strip in the coolant every 15k or at least annually and top off the SCA's if needed. Some coolants, like Fleet charge (NOT Final Charge which is an OAT based ELC) or Napa fleet coolant come with the SCA's already in the coolant.

https://www.cumminsfiltration.com/ht.../supp_add.html

Heavy Duty Coolant & Antifreeze - About Fleet Charge | PEAKhd.com

 

Engine serial# 940614 and higher will determine if you can run ELC. If it was built in 02 you should be fine but better to be safe and check your numbers.