Changing Fuel Filter, Water Separator on CAT engine

[jmgrigsby]

Brett,

My MH is still in the Repair Shop. Last week they thought it was the Hemi Pump.

it checked out ok. This week they suspect the Transmission.

I think they are guessing. Has anyone had a tremendous loss of power and lots of white smoke out the exhaust?

If so please let me know what they found.

jim

[wolfe10]

Jim,

Is the coach at a Caterpillar dealership?

Brett

[jmgrigsby]

Brett,

No - it is not at a CAT Dealer. As you know Good Sam will only take it to nearest shop. And this was my second tow in 2 weeks. They paid for both towings.

When I talked to this Diesel Truck Repair Center, they assured me they could fix it - so we towed it to them.

The nearest CAT Dealer is in Ft Worth, about 120 miles farther.

If I call "time out" and have it towed to Ft Worth now - I will have to pay towing myself.

Yes I wish I had paided extra to have it towed to Ft Worth. Hindsight is 20/20.

This Truck Repair Center also works on motorhomes - and specialize in Cummins and Caterpillar engines. But I wonder why they are having problems with diagnosis.

Surely someone has had this problem or a similar one - wish someone could help identity problem. What would you do at this point?

jim

[jmgrigsby]

Brett,

The Diesel Truck Repair Center in Tyler is an authorized CAT service center. But I was disappointed in their progress and felt that I was getting a run-around - they had my MH for 3 weeks and seemed to have pulled off of it - awaiting a rep from Allison Transmission, then said its probably not transmission related. So I called "time out" and had it towed to Holt CAT RV Service Center in Ft. Worth. Good Sams paid for the first 50 miles of this tow - I paid $348. Good Sams has paid for towing my MH 3 times in last 2 months. That's the only good news I have at this point. Holt expects to start on it sometime next week. It started and I drove it upon a trailer for towing. No smoke this time. More later.

jim

[mclavey]

This is almost as good as a James Paterson mystery story..... I bet the fuel filter is plugged again .... A tank of bad fuel.

Having had this same problem on my last trip. I had to change a fuel filter on the side of the road about a mile from the Eisenhower Tunnel in Colorado ... I was down to 10 mile per hr. This is the second time I had this happen to me. (I am a slow learner) I now carry a pair of filters with me. I am getting good at this .... it took less that 20 min. and I was back on the road.

I have great sympathy for you Jim.

I will be watching for Chapter 10.

[jmgrigsby]

Brett,

I just got a call from the Holt CAT rep - here's what they found - the electric primer that the Truck Repair Center installed was causing a restriction in the fuel flow. They disconnected it and the MH had power. I went over and actually test drove it myself and yes it accelerated pretty good( I'm not sure it had the power that it had originally but it's had to tell, it definitely is better than when I got it out of the Truck Repair Center, remember it's top speed was 35 mph). The Holt CAT rep said that when I changed the fuel filter - that solved my "loss of power" problem - if I could have started it then everything would have been fine.

Holt CAT is also installing the secondary fuel filter with primer - I could not get a 10 micron filter from Freightliner, so Holt CAT plans to replace the original filter base and install a 10 micron CAT filter with separator(no sight bowl however).

I have spoken to the Truck Repair Center(an authorized CAT service provider) and they said they would give me a refund - don't know how much refund yet - but the electric primer cost $450 plus $350 for towing to Holt and Holt's bill is $1300 to find the resriction(I'll still owe for adding the secondary filter).

So to all you folks that have only one fuel filter - when you change filters be careful not to spill any fuel and pray that it will start! I hope this is the last chapter of this thread! I'll give it a good test run when we head to Colorado.

jim

[Spike45]

I have a 2004 Coachmen 38-foot motorhome with a Caterpillar 3126 engine. Could someone please explain how to change the Fuel filter/Water Separator? And do I have another fuel filter? if so, where?

Thanks for your help.

Jim

Caterpillar provides the base fuel filtration on the engine build. If they designate a fuel water separator, it is provided. I suspect Caterpillar is like Cummins in this regard; the chassis builder orders an engine with specific options that Caterpillar makes available like fuel water separator (in addition to standard fuel filter), coolant filter head, remote lube oil filter, or accessory bypass oil filtration.

The chassis manufacturer often does not order some options as the cost is higher than what they can get the feature for with an aftermarket company. One such area is the addition of the fuel water separator. It is possible to find a Racor or Fleetguard fuel water separating filter on chassis. If that FWS product is the only filtration on the engine, it must meet Caterpillars micron requirement of 2 micron particle removal.

Draining FWS can be a pain, no doubt, as access may be governed by an on-engine installation vs. remote mount. You may be able to install a FWS product that has a WIF, Water In Fuel sensor. Check to see if your MH manufacturer offered that as an option. If they did, there may be a wire harness connector for the dashboard WIF light. Fleetguard offers the FS1242B fuel water separator kit, available with WIF sensor system. Fleetguard FS1242B

Racor, division of Parker Hannifin also has WIF sensor fuel filtration that you can add onto the system ahead of the engine-mounted fuel lift pump. Racor FWS

Adding these remote Fuel Water Separators will encourage draining if you mount them in an accessible location. It is advisable to drain the FWS after taking on fuel. Give it some run time to strip out water. Even though most truck stops and travel centers take diesel fuel deliveries more than once per day, you cannot be certain that the fuel does not have water.

[cvdm@msn.com]

Hi Brett,

I am having the same problem. I devised a way to pressurize the fuel tank with 25 PSI. I do not have a way to let out the air out of the filter other than the drain at the bottom and a plug, or too disconnect the outlet line (this is what I did and it had no fuel in it). When I pressurized the tank I got a good flow of fuel. So the line is primed to the filter but I still can not get it to start. Can I try starting it while I have the tank pressurize to get it to the pump?

Thanks for all of your advise.

Chris

Jim,

As discussed throughout this thread, getting an air lock is not that difficult-- if the level of fuel is below the filter housing, it is easy to have that 30+ feet of fuel line all drain back to the tank-- leaving 30+ feet of air to be purged. With no manual primer pump (which some chassis builders left off to save a few $$, an air lock is difficult to purge.

A manual shut off at the primary filter housing intake (fuel tank side) would prevent this.

The new manual primer pump on the secondary filter will also allow you to easily bleed the air from the system.

Bottom line, this is not an uncommon problem, but one that can be easily prevented.

Let us know how they removed the air lock-- the common way is to slightly pressurize the fuel tank with compressed air while opening the bleed screw on the filter.

Glad you got it going-- now you and Willie Nelson can go back to singing "On The Road Again".

Brett

[wolfe10]

Chris,

Welcome to the FMCA Forum.

First, 25 PSI is a lot more than I would use. You only need enough to move fuel from its level in the tank to the level of the fuel filter. Heck, with 25 PSI, you could have the fuel filter on the roof and still have adequate pressure. More importantly, I am not sure that the fuel tanks were designed for that kind of PSI. 5 PSI should be enough to raise the fuel from tank level to filter housing level.

You don't say what kind of fuel system you have-- will need to know that to answer the question.

Do you have one or two filters? Manual primer pump?

What engine? And, have you looked in the manual for recommendation for final bleeding of air. With some, after most of the air is purged (which it sounds like yours is), turning the key on or activating the starter will finish the fuel bleed process.

BTW, bleeding the air from the outlet IS the correct way to do it.

Brett

[cvdm@msn.com]

Thanks Brett,

I have the same set up as Jim. Cat CFE3126 engine with a Freightliner XC chassis and one filter with a clear bowl, no pump. It is the correct micron filter that you have been talking about.

I have try at least 5 time to try and start it. Does the fuel pump run with just the key in the on position? The Manual does not say anything about final air bleed.

Chris

[wolfe10]

Chris,

To answer the question on Caterpillar recommendation for final bleeding of air from your particular engine, give the Caterpillar RV Hotline a call with your engine serial number. They can look up for you the procedure: 877 777-3126.

And, as I have mentioned before, if you are going to keep the coach, I strongly recommend you consider installing the second fuel filter with Caterpillar manual primer pump. Sure makes this easier. Freightliner went back to building their chassis that way as well.

[daPrinc]

Brett,

I have a 1998 National Tradewinds with a 3126 CAT engine with 2 fuel filters and a hand primer pump. In talking to a mechanic the other day I was told to fill the fuel filters with ATF (Automatic Transmission Fluid) instead of diesel. He said it was a little thicker, the red color would show up better if there is a small leak in the fuel line, would clean the injectors and that a lot of truckers put a quart or so in their fuel when they filled their tanks. Have you ever heard of this and what is your recommendation?

[wolfe10]

daPrinc,

Welcome to the FMCA Forum.

That advice is decades old.

With the two filter/manual primer pump system you have, the recommendation from Caterpillar Corporation (not my opinion) is:

Install filters dry and use manual primer pump to prime.

Does that take 3 minutes longer than filling the filters with fuel or ATF that may be clean--YES.

Is it a short cut that diesel techs use-- YES.

Is it the "Best Practices Recommendation"-- NO.

If you are here in Madison at the FMCA Convention, on Thursday morning at the Caterpillar RV Engine Maintenance Seminar you would hear exactly the same thing.

As a side note, I have the same fuel filter arrangement and that procedure has worked for me for the last 156,000 miles.

Brett

[daPrinc]

Thanks for the advice. My CAT seems to have a problem starting at altitude (6500 ft. or above) and I thought that might be a solution.

Have fun in Madison. It is a beautiful city. I was there a few years ago for a technology conference for public schools, but unfortunately I am not there this week.

Thanks again,

Joe

[wolfe10]

Joe,

Once primed, there should not be a need to re-prime. Need to re-prime would indicate an air leak at a filter or line from tank to engine.

Hard start at high altitudes, which usually means low temperatures, means you should start by verifying that the correct starting procedure is followed (see your Caterpillar Engine Manual). If still a problem, verify that the intake heater is functioning properly.

Brett