My recent experience with diesel fuel systems brought a question to mind. Is using an external pump to pump fuel into machine through the fuel tank supply hose to prime have any negative consequences? Sure would solve difficult machines, right? Any thoughts ..?
On my wife's common rail TDI, I pulled fuel through the filter assemblies with my oil extractor. https://www.amazon.com/SUPERFASTRAC...t=&hvlocphy=9033433&hvtargid=pla-781685089906
I carry an electric pump on my truck, but seldom use it. There is a slight chance something might be damaged by pressure, but by the time you break out the pump you are usually so desperate you don't care. I splice it in somewhere convenient, and open a bleed screw further up close to the injection system. I want to see when the fuel comes out anyway.
That was the nice feature of the oil extractor, not a big force and it pulls the fuel from the tank. If you have a holed line somewhere, you will see the bubbles.
A member on here NH575E, uses an electric pump when he changes the filters to prime. He says it works good.
I always take a few rags and turn them into a ball the size of a grapefruit . Then put a small air blower pipe into the fuel tank with the rag acting as a cork behind it. Push continuous air into the tank as someone else cranks over the engine for you. You will feel the air blowing back on the rag ball or might even see some vapour pushng back as you apply the air. It will put about 1 PSI into the tank and have done it for years for trucks on the side of the highway out of fuel at Minus 30 Fahreinheit. It got them going once we put fuel in tank. If there is any connections at the exit side of the filter that can be loosend, the fuel will leak out in 30 seconds or less. Have saved many a customer this way. Try it but be mindful that if you go crazy with the air you will have a diesel bath cause the rag ball over the pipe will not hold excess pressure. I put one finger in a glove under the air nozzle trigger to prevent pushing down to far on the air. Hope it helps. Simon
A fuel injector pump only knows the supply pressure it has to work with. How it gets the needed supply and pressure it is ignorant to.
I see a lot of supply lines w a boat squeeze bulb.. If they’re rubber lines.. and it should be installed before the filters.. If not, there’s a chance the injection pump will suck it flat.. AND.. there’s a difference between bulbs.. do not run down to Walmart and get 1.. if u have a boat center near u, that’s the place to go.. Yamaha makes the best one..
A high quality 2-3 gallon pump sprayer works good. Especially, when the engine has a quick connect fitting.
I always use a little hand pump attaching to the inlet fitting on the primary fuel filter. Over the years I have a selection of fittings just for the task. I bypass the lift pump and can usually hear the fuel return to the tank after the filter(s) and gallery are filled. If not, I pressurize to 30 psi and start the engine, shut it back down, reconnect fuel lines, and then the engine is restarted.
I’ve had various primer pump set-ups through the years. My favorite was a Caterpillar filter head w/pump & fuel pressure gauge equipped with a 1R-0750 HE. Hoses and a various assortment of fittings that all fit nice & clean in a pail. I was showing my students how to use it in a fuel systems class I was teaching. Came back to the lab after lunch and the entire set-up was long gone. Been keeping my eyes open for another Cat filter head.
Funny story. This time in Anchorage. I was renting a tanker bay from a vendor whom I farmed-out a lot of work to. I was doing some major work to a 11,000 gallon 53 footer that I didn’t have room for. Anywho, three days prior, a Kodiak with a Cat 3126 belonging to a moving company arrived on the hook that had ran out of fuel. The Tech, at this point had almost 16 hours of labor, set of batteries, filters and a tow bill invested in trying to get this thing started. He was now replacing the HPOP. Curiosity got to me and I asked about the project. Hmmmm. I said, put it back together and I’ll show you how to start it. I retrieved my primer pump and told him to put this hose in the fuel tank, snap this hose onto the fitting near the fuel filter and pump until your arm goes numb. Then switch to the other arm. 5 minutes later, I heard it start up from across the facility. Lol.
Today, I’m rocking the old-school Detroit hand pump. Takes me back to a simpler time, when Detroits only needed two-strokes and diesel came in one flavor.
I use to prime mine with a air gun and rubber stopper with a hole in it. Last time I needed to prime it I used an electric pump with good results.