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Cat Coolant in Fuel

Discussion in 'Truck Talk' started by RETIDEPXE, Apr 28, 2012.


    RETIDEPXE Rookie Expediter

    Problem is a small amount of red coolant showing up in my fuel water separator for the past 50,000 mi.s....probably an oz. of coolant every 2000 mi.s. The coolant recovery tank finally showed up today with one drop of fuel floating on top the coolant. Not enough in the bottom of the fuel tank that I can see it there. 1st thought is head gasket leaking into the fuel port that feeds the injectors in the head. I pulled the injectors thinking an inj O-ring was leaking, but realized the inj. O-rings do not seal out the coolant there, just the fuel from oil. No coolant in inj. cups/ports visible. Anyone else experience this?

    '06 Cat C9 ACERT
    700,000 mi.s
    No APU
    No Espar or other fuel fired type coolant heaters
    No fuel dilution in Polaris labs Oil Analysis (<1% - Estimate)
    No postassium in Oil (0) so no coolant in oil
    Motor has not run hot, if anything, too cool 185 to 190 degree area
    Added a quart of coolant in 50,000 mi.s
    Motor has no EGR or DPF

    Poor man's fix of the day if you wish to follow. While the injectors were out, found a couple inj. nozzle holes clogged with build up visible with a magnifying glass. I experimented here with cleaning, soaked the tip in inj. cleaner, brushed with an old tooth brush (don't use a wire brush, this will damage the nozzle spray holes) and under the mag. glass scraped away the crud carefully with a razor blade, used the point of the smallest sewing needle to clean the worst nozzle holes, then blew out with an air gun. While the engine seemed fine before (unnoticeable slow degradation thing), the cleaning went well as even the Mrs. commented the engine seems to run smoother. First 50 gallons out ran 9.89 mpg, no wind, no hills, usually around 9.5. Just installed bearings in steer hubs so partly due to this.
  2. Doggie Daddy

    Doggie Daddy Active Expediter

    How many engine hrs on that C-9?

    Sent from my DROID BIONIC using EO Forums

    RETIDEPXE Rookie Expediter

    15,591 hrs on the clock. No idling, using a Honda eu2000 while sitting.
  4. zorry

    zorry Active Expediter

    Is there a fuel cooler ? I now nothing about those little cats, so that would be an early question for me.
  5. Dynamite 1

    Dynamite 1 Moderator Staff Member

    first thought to me is a small head gasket leak. did you pull out the injector cups and inspect. could be something going on under the cups. i have heard of small cracks appearing in the head in this location which could cause a gasket failure also. just a guess. acert is cats form of egr, its just recirculated back through the engine in a different way. dont know enough about it to know if coolant is involved in the acert setup but it would be a good question.

    lastly, what did the bearings cost you to buy ? i have been studying this for awhile now and seems to be a very good idea for lots of things.

    RETIDEPXE Rookie Expediter

    Zorry, no fuel cooler, goes tank to fuel/water fil. to fuel fil. to pump to head galley and injectors out the back of the head to fuel pressur reg. to tank (I have a pdf of the C9 fuel system, PM me an email address if needed). I have about determined the HUEI pump is not water cooled so this narrows it down to what Dynamite is sayinig, makes sense anyway. I did not pull the injector liner/cups, gotta study on that one (do you have to pull the head to do this?, but the # 6 injector bore had more then normal amount of crud in it to clean out. I'll follow up in a month. I don't see how it is hurting the engine as long as I keep the fuel/water separator drained and the oil analysis shows no coolant or fuel in the oil.

    Dynamite, the prices are posted for diff sets at their website; CLASS EIGHT TRACTOR/TRAILER BEARINGS - TRACTOR BEARING SETS - MicroBlue Racing, Inc. Store
    another page has prices for trailer axles. My M2 has the Daimler/Mercedes steer axle (dealer can tell you axle make and bearing numbers) and required the Std set for $375. Cost me about $400 w/ 2 day UPS. Installed them myself, they have a nifty bearing removal and installation guidelines downloadable here about half way down the page; TRUCKING UPDATES

    Note; Use the guidelines, especially the part about using the dial indicator (Sears - about $75 w/ magnetic base) to set the .003 to .004 in. end-play and part about removing the old races. Be careful not to "roll" the metal/alum or iron as stated in the guidelines. I had an experienced welder do the beads for race removal on my alum hubs and I told him I WANTED TO REMOVE the old races myself. When I got back, he thought he was doing me favor by already having the races knocked out with his massive rusty punch and maul hammer doing exactly what the guidelines warn against. In his defense, I did not explain in detail why I wanted to do it myself so I didn't say anything, but it took me a couple hours to sand that mess out, so be careful. A press is best. My old bearings had a lot of miles but still looked good short a stain here and there, but the microblues absolutely feel smoother and I notice the truck will coast better in gear, throttle off, without loosing speed on the slightest downgrade now with even a light load. On my second tank and w/ gauge at halfway mark, trip odom is hitting 600 mi.s, usually hits half around 475 mi.s, so we will see.....of course, i have a heightened sense of nursing the pedal as best I can to convince the Department of Interior the high dollar bearings (and extra tools purchased) were worth the money if you know what I mean.
  7. davekc

    davekc Senior Moderator Staff Member

    Not sure if it helps your situation, but we had a similar situation and it turned out to be a cracked injector tube. Very difficult to detect.

    RETIDEPXE Rookie Expediter

    "cats form of egr, its just recirculated back through the engine in a different way"

    Found this on ACERT and learned there is no exhaust gas recirc in it, interesting vid on youtube.

    Caterpillar ACERT Technology - YouTube
  9. Deville

    Deville Rookie Expediter

    I recall a friend of mine had a similar problem, Don't quote me on this because it was a while ago & I don't recall the EXACT problem but it was somthing to the effect that he had a bad gasket that seperated the motor from the cooling system & it was causing coolant to get into the fuel & fuel into get into the coolant. They had to take the front of the motor apart, inculding removing the cam shaft to get correct the problem. It wasn't alot of money to fix from what I remember, maybe $1200.

    RETIDEPXE Rookie Expediter

    Just an update, problem solved. Turns out I was also getting fuel in the coolant, along with coolant showing up in the fuel/water separator, but had no coolant in the fuel tanks when I drained them. Apparently there is a return line going strait to the fuel/water sep. Anyway, I pulled my injectors and found, with pressure test, #5 inj sleeve had a small drip of a leak. I pulled all inj sleeves and although the o-rings were rotting, the #5 looked like it had been installed from the factory with some trash in the hole. It was amazing how much flushing I had to do to get all the fuel out of the coolant passages, it obviously does not all float to the top of the recovery reservoir. 3500 miles since repair and no more coolant in fuel or fuel in coolant. Life is good.
  11. Turtle

    Turtle Administrator Staff Member

    Thanks for the update.
  12. Deville

    Deville Rookie Expediter

    Good news!
  13. spongebox1

    spongebox1 New Recruit

    Mirror symptoms, do you have a pic of the sleeve tool you made?

    RETIDEPXE Rookie Expediter

    The time I have to describe the procedure is minimal here and is not meant to be all inclusive. Please do not attempt this without due diligence on injector r & r and knowing other important things like draining the diesel from the fuel rail and oil from the oil galley first, sucking dry the tops of the pistons before going back together, and using a plug of some sort to prevent the metal filings from the tap from falling into your cylinders.

    I am on the road and won't be hm (where the tool is) until mid April, but, just picture a 1"-14 thread tap with about a 3/8" bolt welded upside down on top of the tap. Make sure your tap won't bottom out in the head before it gets a good grip on the sleeve. I had to grind about 3/8" to 1/2" of the tapered bottom of tap off of my tap to prevent this. Plug the hole with a coin or I used a plastic fastener like pictured here; PDQ Online Hardware Store-FREE SHIPPING orders over $75 Get one that fits well in the bottom of the sleeve, cut most of the point off and it will come out with the sleeve and catch the filings. Thread the tap into the old sleeve about 1/4 to 3/8 inch, slide the steering wheel lock plate remover, one like this; OEM/Steering wheel lock plate remover (27044) | Steering Wheel Lock Plate | over the upside down bolt, thread a nut on the bolt and crank the sleeve out. I had to do some grinding on the lock plate remover in order for it to fit between the rocker arms. Also, I had to put a carpenters clamp around the lock plate remover to keep it from spreading apart when torquing down the nut to pull the sleeve. Amazingly enough, the sleeve will pull right on out, all this done without pulling head and while the motor is still in place. Scrub out the injector bores good with a scotch brite pad. I used a long needle nose and a sponge type scotch brite pad for this. Vacuum out good including tops of pistons. I used a shop vac with homemade attachments sizing down to a 1/4" plastic tip that will fit thru the hole at the bottom of the injector bore to reach the top of pistons. Install new sleeves and lithium based greased o-rings using an installer tool or make your own as I did, went to Menards, found a hard plastic handled screw driver that partially fit into the new sleeve I had, then torched hot an old sleeve and melted the handle to fit nicely into the sleeve. THen cut the shaft of off and walla, a nice sleeve installer tool. Just lightly pound the sleeve till it bottoms out. Get a good light and mirror and make sure sleeve is seated in the bottom of the hole. Renstall injectors with new lithium coated o-rings and back up seals. Note, I prefer the plastic back up rings for the injectors instead of the metal rings which are darn near impossible to install.

    I did mine at 723,000 miles, just turned 850,000 miles on original motor, no rebuild and going strong no problems.

    Disclosure; This information assumes no responsibility for damage or injury, all just talk under a shade tree.

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