Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 21, 2025 ...

Fuel delivery

January 06, 2014, 03:48:25 pm

Have 1996 U295 w/3126 Cat. Experiencing starting problems, have traced down I believe to fuel delivery issue from tank to fuel/water separator. Wondering if there is a fuel pump located either in main fuel tank or somewhere in between.

Quote Selected

Re: Fuel delivery

Reply #1 – January 06, 2014, 04:38:44 pm

No, the fuel pump is on the engine.

So check the primary fuel filter/water separator for any air.  That would indicate a leak between tank and the filter (including filter).

Fuel then goes to lift pump and then to the secondary fuel filter.  Then to the engine.

If your secondary fuel filter housing has the Caterpillar manual primer pump, unscrew it (counter clockwise) and pump.  If easy to pump, you have air in the system.  As soon as air is purged it will be go from very easy to VERY hard to pump.  Push it in and screw it clockwise to lock closed.  If your fuel system is good (no leaks) you should not be able to pump it more than 2-3 times. When changing filters, it may take 50-100 strokes to prime both filters (which are installed DRY if you have the manual pump).

If you will be at the Perry GA FMCA Convention, come to the Caterpillar RV Engine Maintenance Seminar-- I'll be presenting it.

Brett

Quote Selected

Re: Fuel delivery

Reply #2 – January 06, 2014, 05:00:24 pm

Primary fuel filter when I opened drain contained very little fuel. Priming pump located on primary filter housing - pumped excessively never built pressure as before could with 5 - 10 strokes. Have purchased replacement primary and secondary filters and when weather permits will install. Planned to install wet as that is how I have seen done in the past. Should I install dry?

Quote Selected

Re: Fuel delivery

Reply #3 – January 06, 2014, 05:11:41 pm

Steve,

Please verify that the manual primer pump is on the SECONDARY fuel filter housing, not the primary filter, water separator.  It is important to know which is which, as the primary can use a 10 or 30 micron filter element, the secondary MUST BE a 2 micron per Caterpillar.

If you can pump many times and the pump not get hard to pump, either you have an air leak before the manual pump OR the check valve in the head may be leaking.  It is in the back of the head (toward from of coach).  The return line comes off it.  Easy to replace and not very expensive.  But first thing is to verify that there is no air in the fuel lines, as that will stop ANY diesel.

PM if you need more info and I'll send you my phone number.

Brett

Quote Selected

Re: Fuel delivery

Reply #4 – January 06, 2014, 05:17:04 pm

Many of us with 1996-1997 coaches have found that the fuel lines have deteriorated. The failing fuel lines allow air to get into the supply lines. Our indicator was that the generator would not keep running after carefully priming the system. Fortunately, the "big" engine did keep running and did not leave us stranded. We had the lines replaced at FOT.

Quote Selected

Re: Fuel delivery

Reply #5 – January 06, 2014, 05:48:28 pm

Brett

Primer pump is part of the primary fuel/separator housing. Check valve on the back of the head recently rebuilt.
If filter replacement (both) doesn't cure suspect fuel line from tank to primary filter - have replaced line from secondary to engine as found small leak from rubbing. Hose did not appear excessively deteriorated so hoping line from tank in the same condition. Thank you for your responses - nice to be able to discuss

Steve

Quote Selected

Re: Fuel delivery

Reply #6 – January 06, 2014, 08:06:40 pm

Steve if Cat is same as my Cummins from fuel tank all the way to engine mounted fuel pump is vacuum.  From fuel pump through engine back to tank is pressure from fuel pump.

I had to replace fuel line from tank to fuel water separator with no visible leaks on hose but it would not hold vacuum.

I rigged a fuel hose from a five gallon bucket to the inlet on fuel water separator to isolate problem. 

I ran a temporary hose from fuel water separator by splicing into original as close to fuel tank as possible to get home. 

Larry
98 U 270

Quote Selected

Re: Fuel delivery

Reply #7 – March 18, 2014, 10:29:55 am

On my 3208 Cat, should the fuel/water separator ( primary ) filter be changed as often as the secondary filter. Also should the new filters be installed full of fuel as I did with my 5.9 Cummins Dodge truck?

Quote Selected

Re: Fuel delivery

Reply #8 – March 18, 2014, 04:01:55 pm

Jerry,

When we had a 3208 we put the filters on dry then used the hand pump that was built on the filter base to fill them. Never had a problem loosing suction or getting all the air out with the hand pump. Brett W is the Cat Man and he may chime in .

Pamela & Mike

Quote Selected

Re: Fuel delivery

Reply #9 – March 21, 2014, 02:26:18 pm

Thanks all. Just finished with all the filters. Have to say that the fuel filters are the worst to change. Brett said to pump 30 to 50 times, but I quit counting at 50. But all is good. Started right up and ran long enough to be sure it was going to be ok.
Jerry

Quote Selected

Re: Fuel delivery

Reply #10 – March 21, 2014, 07:16:03 pm

OK, so good exercise and it started right up-- good job!

And, yes with dry primary and secondary fuel filter, it takes a lot of pumps.  Lots of volume in those two filters.

Quote Selected