New to pumping diesel

[berginaperzina]

We are new to the Diesel world, switched from gas, Is there a secret to pumping Diesel? it is so foamy and it seems like if you put it in to fast it backs out?

[wolfe10]

We are new to the Diesel world, switched from gas, Is there a secret to pumping Diesel? it is so foamy and it seems like if you put it in to fast it backs out?

Please tell us more about your problem:

What rig do you have?

Does the slow fill/fuel and foam backing out happen when tank mostly empty, or just when mostly full?

At all fill locations, or does angle of coach affect this?

Are there any SAGS in either the FILL or VENT lines from side of coach to fuel tank?

Does it still do this if you use the jacks to RAISE the fuel fill side of the coach?

Brett Wolfe

[tbutler]

Welcome to the forum Joe and Karen,

I see from your profile that you have a National RV Tropical with Freightliner chassis and Caterpillar engine. While not specifically familiar with your coach model, I can guess that you have a large 75 - 100 gallon tank and would assume the problems with foaming of diesel fuel and feedback happens as the tank nears full. If that isn't the case, the fuel filler tube must have a sharp bend in it as Brent mentioned above. My tube is short and feeds directly into my tank. I only get feedback as the tank nears full. I solve this problem by tilting the coach away from the side I am filling on. With air suspension this is easily accomplished by raising the side used for filling while lowering the opposite side. This delays the feedback until the very last fuel into the tank. I never do this when fueling before parking as there needs to be some air space at the top of the tank for expansion due to temperature change of the fuel. If I am going to drive away from the station and go some distance then I'll pack in all the fuel that I can using this method.

If you have jacks to raise your coach, tilting might be more of a problem. First, I would never use the jacks on asphalt without some boards or other support to keep them from damaging the surface. With three jacks, put the front (single jack) down first then raise the side where you will be filling. The jack arrangement is made to pivot on the front jack and tilting will not strain the chassis and will allow the fuel to flow into the tank until just the side near the fill tube is empty. If you have four jacks, the process must be done more carefully as the two jacks on the high side must be used in harmony, neither exerting more lift on the frame than the other. To do otherwise will put a twisting force on the frame. If you use the two jacks on the fill side and raise them carefully so that both are lifting the coach equally, you can tilt the coach and fill the tank near full.

The foaming and feedback can be controlled by slowing the flow of fuel from the nozzle. This is more easily accomplished with the smaller nozzles common at diesel pumps for the general public. Using the diesel pumps for trucks at a truck stop gives you a larger nozzle and much higher fuel flow rate. Truck tanks typically have no tube into the tank. There is simply a hole at the top of the tank. This creates much less problems for truckers. For those of us with a filler tube, our solution is to slow the flow of fuel to reduce the feedback. When it does start to back up, best to stop rather than spill fuel.

Even if you do have a sharp bend in the fill tube, tilting the motor home may help reduce the foaming and feedback as it would increase the slope of the angle of the tube where it enters the tank. This should allow the fuel to flow faster into the tank and reduce feedback. If this doesn't work, you may just have to slowly fill the tank and deal with the feedback as it occurs.