fuel tank access

[Robert K]

I had to get towed in on my last hundred miles of trip to Maine. I thought the problem wasfuel filters.
I stopped at rest area to change and could not get primed.
This has the little push button primer on the filter and i even tried breaking the line at splice from tank and priming but would not pick up from 2' of hose.
I have it back at our shop and mechanic will hook it to computer , but I am wondering if the pickup line in the tank is clogged.

I thought I had read a post about someone cutting a hole in the floor to get to sending unit but can't find anything.

will repost when I find problem.

[wolfe10]

If the level of the fuel filter housing was ABOVE the level of fuel in the tank, all the fuel would run back to the tank, leaving you with 30' of AIR. That is a lot to bleed out with the little primer pump.

If that happens, "Plan B" is to loosen the filter from the filter base. Put a diesel catch bucket under the filter. Use compressed air into the diesel fuel filler (just put your hand over the opening and shoot the air nozzle into the tank. When your helper sees clear diesel with no bubbles coming out the filter, tighten up the filter. You have just removed 30'+ of air that needs to be purged.

[Robert K]

got the engine running but it is still running with big loss of power. It runs OK sometimes and it will sit at an idle ok.
pressure test the line from the tank it was good.
I am going to drain tank and hopefully scope it and check the pickup line.
Have checked all the lines in engine compartment and will be replacing some but only as a preventive measure.
Also will replace racor filter head and go back to racor bowl and filter. It has had a spin on filter since I have owned it.
Also plan to replace the huei pump. When hooked up to computer it show 255 actuation codes and have reset it a couple of times when checking things and have changed the sensor.

[TDJohn]

Bob,

I strongly suggest that you contact Dave Atherton (retired CAT master troubleshooter) before you start replacing CAT fuel system parts. He is really good and has saved many people tons of money, by avoiding unnecessary expensive repairs. If you are getting air into the system or have fuel flow restriction, the HUEI fuel system will throw all sorts of codes. Per Dave, the primary filter should be rated for 90 GPH flow capacity. A restrictive filter alone can cause all sorts of problems too.

Dave's number is: 605-997-0720

Be sure to have your engine model and serial numbers in front of you, when you call.

[Robert K]

What filter are people running to get the 90 gph. The 90gph racor will not fit unless you unbolt it to access the water valve.
I did look at the flow rate on the win filter I was using and it is only 12 gph. But I had that filter on for the last 6000 miles.

I have scoped the fuel tank and did not find anything but some crud on the bottom. The attached picture is thru the supply line which runs from front of tank to about center of tank. You can actually feel the tube thru the drain plug.
I have flushed the tank a few times and only got small pieces of gritty something.Not metal as it won't stick to magnet.
I think the yellow color is the tint of the fuel and the led on camera.

[Glenn]

Hi Robert,
Here is some information on the Winn Racor filter/water separators that were installed in our rigs that may be of help. Parker now supplies filters and support for these units. Sometime in the early 2000s when the original Racor 90S1230C filter elements became obsolete, Parker supplied an Intergrated Retrofit Kit, Parker # RK12963, to replace the original Racor filter element with a Parker S3230P element. This kit also supplied a cast metal bowl that fitted to the bottom of the filter element. Hopefully your Racor unit has this upgrade installed.

Several years ago while purchasing replacement filters I started reviewing filter specs. I discovered that while the original Racor filter 90S1230C was rated at 90GPH, the Parker filter S3230P was only rated at 60 GPH. I called Parker customer service to ask why this was, and I was forwarded to an Applications Engineer who stated that they would never have done this but that he would check into it. Well about 10 minutes later he called back and stated that he couldn't understand why they had done this, but there was another Parker filter that would fit and was rated at 90 GPH. This filter is Parker # S3201P, and is identical to the S3230P except for the GPH rating, and it is about half again taller. I've switched to this filter, and the only modification I had to make was extending the plastic drain line from the bottom of the bowl to the water drain valve. Safari seemed to rearrange the components on the engine service panel frequently, so you may not be as lucky.

The engine problems you are describing may be caused by air in the fuel system. On the Caterpillar engine the only fuel pump is on the engine so when the engine is running the fuel line from the tank to the pump, including the Racor unit, is operating at a vacuum. So, if you find any fuel leaking from anywhere along the fuel line when the rig is parked, then air is leaking into the fuel line at that point when the engine is running. One common leak point is the Racor pre-screen #300200 located on the Racor unit. This is the clear plastic filter with the internal fuel screen, check it carefully.

If there is fuel on the outside of it, it is leaking air into the fuel.
If it is yellow or brown instead of clear, it is too old and has micro-cracks that are leaking air into the fuel.
If the thumb mounting screw is tight, but you can rotate the filter, the plastic housing has shrunk, and it is leaking air from the ends.
If the filter isn't perfectly vertical between the upper and lower mounts, the pressure on the O rings is uneven and air can leak from the ends. Loosen the thumb screw and move the upper cap mount point until the filter is vertical.
There are four O rings on this filter, two at the top and two at the bottom. Only two come with a new filter, size #208. The other two are grooves, inside the Racor upper and lower filter mount points. If these two O rings haven't been changed in forever, they may be hardened from age and be leaking air into the fuel.

So take a close look at the 300200 pre-screen. It takes a bit of finagling to get it installed correctly, and leak free. You can't just toss it in and tighten it down.

If none of this helps, I also recommending contacting Dave Atherton. He has been very helpful to me in solving some problems, and I'm sure helped hundreds of others by now. He is an excellent resource.

[TDJohn]

Bob,

Those dark spots sort of look like the algae that can develop in diesel. If your filter is only 12 GPH, it is too restrictive and also will clog a lot more quickly, especially if you get a batch of algae contaminated fuel. I know of one member that had overheating issues and lack of full boost. On Dave Atherton's advice, he installed the correct 90 GPH filter and his issues went away. Maybe you got away with this restrictive filter because you region of the country is not as hilly?

[Robert K]

The problem was the fuel line from the tank.
Replaced it yesterday put on 100 miles running good.
I dropped the fresh water and gray tank to access as much as I could and to see how they secured the lines.
loom clamps about every 3' with zip ties in between.
my connection did not hold so had to go thru a different area on the frame about 5'on the front and 4' at the rear. The hose is on the bottom in the rail.
The fuel line was expensive @ about $15 a foot x 31'

I also installed a new Racor filter head and an R90 filter new lines to the heui pump and new line from pump to secondary adapter

Now on to new tires and a new 12 volt fridge

[TDJohn]

Bob,

What model is your old refrigerator that you are removing?

[Robert K]

John it is a 682 Norcold