fuel cooler problem

[JONNYLOVESTRUCKS]

seems Im having a spate of problems with the truck at the moment.
all the coolant in the small tank for the fuel cooling system seems to be pushed out through the vent pipe. This happens within a few miles of use? any ideas?
What would happen if this system ran dry

[mdavis203]

Have you tried purging the air from the fuel cooling system? You remove the plug next to the turbo actuator, fill the fuel cooler reservoir system until fluid comes out of the plug hole, then put the plug back in. You may have air in the system.

[JONNYLOVESTRUCKS]

thanks I will try that! what does the plug look like (color/size) thanks. I have reason to believe this system has been run dry for a while. Is there a pump to this system?
my local ford techs did not even know what the reservoir was for or what went in it. this would be comical if they were not the guys that did my servicing.

[greasltn]

The plug you need to remove is on the turbo actuator and takes a 6mm allen key. You put a 50/50 mix of gold coolant, just like your primary cooling system. There is a pump for the system on the driverside bottom of the fan shroud.

[RegB]

Hi,
I'm new here, I'm trying to help someone else with a problem that may or may not be related.
Was your truck showing any symptoms and if so what were those symptoms ?

[mdavis203]

When my fuel coolant pump went out, I didn't see any symptoms other than the high temp. If I hadn't had my Spartan, I wouldn't have known. I'm not sure what problems would have developed if I hadn't know about the problem and just let it go. Maybe cavitation of the high pressure fuel pump due to high fuel temp? Just a guess.

[JONNYLOVESTRUCKS]

No symtoms at all just losing coolant slowly, no warnings or fault codes.

[RegB]

Thanks,
I guess you keep watchful eyes on stuff (-:

So, what symptoms could one reasonably expect from fuel cooler failures ?
It isn't as if diesel fuel evaporates like gasoline when it gets hot - nothing like the vapor locks that carburetors used to get way back when.

I suppose there is SOME point at which it matters, but with it going back to a big tank with lots of cooling area underneath the truck I guess I find it hard to believe that it could reach dangerous or problematic temperatures.
{puzzled}

[BigHoff]

I had this issue, and thanks to my spartan tuner, I was able to monitor fuel temp... when it got hot (mid to high 90s), I would notice significant power loss on hills and when passing; when the temp came back down, the power returned. It took me several attempts to get all of the air out.... nominally, the fuel temp should be approximately 10 degrees higher than ambient on a cool day, but should never go above the high 80s on a hot day.

this has just been my experience, some of the more knowledgable folks on this forum probably have more accurate information.

[Capt dong]

good thread. could use more input. i can smell coolant from fuel cooler. dunno temps however. dont see how temps can stay around 80 when its a 100 degrees here.