HELP NEEDED!!!!!!

[Jeff Ramey]

What is this and why is it leaking?

[Gerald Farris]

Jeff,
It is hard to tell from your pictures exactly where the leak is originating or what is leaking. Is the leak diesel fuel or hydraulic fluid? If it is hydraulic fluid as one of your pictures indicates from the oil residue on the side of the tank, it is either an overfilled tank, or a bad/loose cap. However, if it is a diesel fuel leak, you have a cracked Racor plastic prefilter screen housing or bad O-rings at each end of that housing and a full or nearly full fuel tank. If the leak is diesel fuel, you need to repair it very soon or it will leak air into the fuel system that will cause a runability or no start issue because it operates under a vacuum when the engine is running especially as the level in the fuel tank decreases.

Gerald     

[Fred Cook]

Does the leaking substance on the ground appear to be reddish in color? If so it is more than likely hydraulic fluid ( probably ATF) from the reservoir that supplies the power steering an radiator fan clutch. If it is not red and smells like diesel fuel then you may have a leaky hose between the fuel filter and the motor. I had to replace a leaky fuel line hose in that same area about 6 months ago.

[Dave Atherton]

Jeff, what I can see from the picture you have a few problems that is leading you in a direction
of bigger problems ahead. My first suggestion is to remove the two fuel lines coming into that
Racor fuel/water filter along with two elbow fittings. Get a 1/2 pipe nipple and connect both elbow fittings together and reconnect the fuel lines together and by pass the Racor fuel/water filter setup.
( note this is a add on aftermarket filter setup and you can run without this in the system ). Next
Your fuel secondary fuel filter should be a Caterpillar 1R-0751 2 micron fuel filter as per Cat
Service manual. The secondary fuel filter the on the left is under pressure when engine is running
and will remove your fuel system problem along with the Racor fuel/water filters. The only thing now
Left is the hydraulic system filter which would be red fluid color. Going back to bypassing the Racor
fuel/water filter you can run without that filter on your engine and change out your secondary
filter at each oil service period.  You can decide at later point how you might want to address the
Primary filter. Caterpillar did not install a water/fuel only as a option on Caterpillar C-9 and below
model engines. If you are on the road that is my suggestion you are not in trouble in any way
with your fuel system. Dave Atherton Retired Cat Mechanic

[Jeff Ramey]

Thanks all!

It is diesel fuel.

Pic 1 is sideways, Pic 2 is upside down, Pic 3 is sideways, Pic 4 is fine.

It is leaking from around the fuel/water separator filter at the top and bottom, as well as dripping onto the ground from what appears to be an overflow hose? It has a 4" rubber hose coming off the filter and emptying onto the ground beneath the coach (just like an old radiator overflow tube coming off a radiator cap) PIC 2. I tried to show it in the pics above, but it was pretty dark. It's a short little tube on the right (or left when upside down) in PIC 2 taken from under the bay. I don't know what that large oil tank is for in PIC 1 but it always seems to be oily and dirty around the cap and on the side, no matter how often I clean it. Is that tranny fluid, power steering fluid, etc?
I'm glad to hear it's not a huge crisis, but I need to figure out how to fix it soon. It's made a puddle under the coach as seen in PIC 3, and it's got that diesel smell.
Anyone have any idea what that Racor panel PIC 4 is for with the "air purge" and "H2O purge" buttons?
If so, how do I use it?

[Dave Atherton]

Jeff, I guess that the little buttons serviced a purpose in its day but in a OEM system that
engine builder put on as a option is not present. Again as I indicated you can bypass the
Racor water/fuel filter setup and run without a primary filter and use correct secondary
1R-0751 fuel filter ( Caterpillar 2 micron ) and change fuel filter at every oil change period.
If you want to add a Caterpillar water/fuel filter cost for filter and base for filter is less than
$ 100.00 dollars. Note. Caterpillar has never been a fan of any kind of openings in the fuel
system on the suction side of fuel transfer pump. The reason is with the electronic Heui
injection system air entry can be very damaging with injectors and low power. Aftermarket
add on is allowing entry of air into your fuel system . Dave Atherton Retired Cat Mechanic

[Steve Huber Co-Admin]

Jeff,
This provides information on both the CAT and Racor options. It's located on the BAC website (Technical/Common Problems).   http://beaveramb.org/acadp_listings/cat-or-racor-primary-fuel-filter-system/
Steve

[Gerald Farris]

Jeff,
It would have been much better if you had lead off with your explanation because your pictures were so bad that I could not tell what you wanted to fix.

First the oil tank at the top of the compartment is for the engine driven hydraulic pump that powers the hydraulic radiator cooling fan and the power steering system.

Next the diesel leak is from the Racor water purge valve that dumps excess water from the bottom of the primary filter when you push the button marked H2O purge. Since parts are no longer serviced for the electric priming pump and valve system, you will need to replace your primary fuel filter system with a different unit, but I would not install a replacement primary fuel filter without a priming pump. If you decide to use a Caterpillar primary fuel filter, there is one available with a hand operated priming pump, or there are other brands available with either an electric or hand operated priming pump. Just be sure to get between a 20 to 30 micron primary fuel filter/water separator.

Gerald   

[Jeff Ramey]

I apologize for the bad pictures and description. I posted for Jeff to try and help. Lesson learned and will post with more info next time.  ~ Teresa

[Michael Peters]

Jeff, I have the same Racor filter hsg , Racor has a new version with the same features, electric pump, water separator, primary filter. Racor hsg 790R30, $322. Online retailer is Boatstore.com. I haven't changed mine YET

[Doug Allman]

For a third of the cost you can change to a CAT fuel water filter that has no maintenance issues like the Racor unit does. There is nothing to do with the CAT except change the filter at the prescribed times. Maintenance free.
You will also have a quieter idling/running engine with the CAT filter as it has no O rings that allow air into the system. When accelerating there are no O rings in the CAT filter that can allow air to infiltrate the pressurized fuel and thereby create lack of horsepower and performance.

We changed our Racor on our 2004 Marquis C-12 505hp to the CAT and was amazed at the much quieter idling engine. Tach changed from a needle that wavered over about 200 rpm difference to a steady idle speed. The throttle was slightly more responsive and we gained over 6000 miles a 1/3 of a mile per gallon of fuel.       

The CAT engine was designed with a CAT filter system. The chassis or the coach manufacturers engineers evidently had a better idea or saved some $$ when they decided to use an off the shelf brand.  As with numerous other items on a coach the chassis or coach manufacturers engineers borrowed whatever technology in the auto or truck market they could find and in most instances at a $ savings to end up with what we are now fixing. The adaptation of these parts was not always in the best interest of the buyer.

The CAT engine does not run well with any air in the fuel as it has sensors that derate it so you will not destroy it. Use all CAT technology by using their parts and minimize the maintenance and have a well operating CAT engine with the performance you expect from it. You actually pay less in the long run by using all CAT parts and insure the CAT longevity by doing so. Your headaches go away and you enjoy effortless performance traveling with $$ to fill the tank.

Ask Jim Nichols how this worked for him.

[Mike Shumack]

Jeff, I have the same Racor filter hsg , Racor has a new version with the same features, electric pump, water separator, primary filter. Racor hsg 790R30, $322. Online retailer is Boatstore.com. I haven't changed mine YET

Why are you considering changing? Is your current Racor filter assembly damaged somehow? I know the replacement filter is still available.
I believe Dave's recommendation was to just bypass it (leave it out) if there is a problem with it. If you wanted to keep it, I know Dave recommends replacing the plastic push-to-connect fittings (if you have those) on the fuel hoses with brass compression fittings.

https://www.dieselfiltersonline.com/790r30-parker-racor-integrated-assembly-90-gph.html

[Mike Shumack]

For a third of the cost you can change to a CAT fuel water filter that has no maintenance issues like the Racor unit does.

Do you know what the part number is for the (primary) CAT filter and the housing?

[Jerry Emert]

These were provided by Dave A. a few years ago.  I made the change about 2 years ago and noticed a smoother sound to the engine.  I don't track mileage very close though.  Performance is about the same.  CAT parts.
137-4367 filter base, 129-0375 plastic bowel, 133-5673 filter element,  120-6726 elbow fittings need: 2 total cost $ 153.52
Jerry

[Mike Shumack]

I went to CAT parts store and found that the filter (p/n 133-5673) has been updated to p/n 513-4490.
Just to let anyone else know that may want to do this filter install.