Hi Folks- its been over a year since I contributed any useful information to the site so I thought I might start out with this information which might be of some interest to our members.

I recently changed the fuel filters on my 1990 Regency with 8.3 Cummins engine. It has three filters on it. The first is a large Racor water separator located down on the frame. This is an accessory addition to provide some additional protection for the other filters mounted high on the left side of the engine. These two are Cummins provided. One is another water separator and the other is the final to the injection pump.

I changed the Racor first and filled it with diesel fuel and then started the engine- no problems, After that I changed the other two filling them both with diesel. I then pushed the primer button on the engine driven lift pump until I met resistance. Supposedly this should have cleared the air from the system. However the engine would not start. After a couple of hours of frustration, I called a diesel mechanic friend and he told me that filling the upper two with fuel and using the primer would not dispel the air. He said to always leave the final filter backed off two turns and then use the primer to pump fuel until it over flows the filter and then tighten it up. Hold down the accelerator and start engine.

I backed off the final and got a huge hiss of air and followed his procedure and the engine started right up.

Hope this might help others changing their filters.

All right! Let's hear it for the diesel guys!

I have not replaced my filters yet but I know from other diesels air is a big issue. Thanks for the tip Clint.

There are 6 diesel engines around my property. All six are in running order. From a two cylinder Kubota to a 10.4 liter cat.

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I am a diesel nut. In the past I had several Volkswagen Diesels and two Mercedes Diesels. Maybe I am a "Diesel Junkie" along with being a Barth JUNKIE!

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Keep the diesel fuel filters clean and free from water.

On both 5.9L and 8.3L Cummins engines the final fuel filter before the injection pump usually mounted high on the engine near the injection pump has a bleeder screw that is located on top of the filter assembly. I mount the new filter empty and then use the priming plunger on the lift pump to fill the filter until the filter is full and no more air is coming out of the bleeder. Leaving the filter loose does the same thing but I prefer to use the bleeder screw as it is higher and a better chance to get all the air out.

Ed:

Thanks for the info. I did not know about the bleeder and my mechanic didn't mention it. This is much easier than filling the filter and much less mess. You didn't mention the water separator which is located right beside the final. Do you leave this dry as well and use the plunger to fill?

Clint

Yeah I always fill the water separator filter as full as I can first. I only have the two. The filter is located low on the chassis and I do get some gravity flow if I have a full tank before I start with the filter change.

I make sure all areas around the filters is squeaky clean before I start.

I hope this is not seen as excessive thread-drift...
In a week, I am headed to a highly-regarded German diesel mechanic in East Texas. having him replace my eighteen year old rubber fuel lines -- to both the Cummins 8.3 and the 3 cyl diesel generator engine.
It is the latter that initially reveals porous fuel lines. The engine stumbles and stalls. The fuel pump for the genset is a tiny cartridge thing. At first I thought it was a small fuel valve. It doesn't have enough suction to adequately fuel the engine if much air is getting sucked in through bad lines. By contrast, the lift pump for the big Cummins can manage until a much greater amount of air is being infiltrated.

My local mechanic thought the problem was algae clogging, based on brown grunge seen on fuel filters. So, I hired a mobile "fuel polishing" service. I watched them pump and triple-filter dirty fuel from the bottom of my LARGE fuel tank, until it was practically clear.
Before they left, I said "Okay, let's see if the generator will stay running... N O T! But, it did after the tech taped-up the worst area of accessible fuel line.

Unfortunately, the fuel line (like water and drain lines) are concealed and DIFFICULT to access in a "UniHome" monocoque construction Foretravel. In most motorhomes, replacing the fuel lines would be a "piece of cake" by comparison.
In conjunction with the above project, I plan to have Bernd (pron Bend) Ramspeck stop my engine oil leak -- by replacing timing cover seal, crank seal or both :^(

Why not bypass them with stainless steel lines (not the braided type) along the frame rails and then use short rubber for the last foot? Ends the problem forever!

quote:

Originally posted by Tom and Julie:
Why not bypass them with stainless steel lines (not the braided type) along the frame rails and then use short rubber for the last foot? Ends the problem forever!

NO frame rails!!!

Nick

Monocoque construction