Secondary fuel filter loses prime--Volvo D4-300

[Bruzer]

Our Ranger Tug, a 2020 R 29 S LE, HIN: US-FMLT2915K920, with a Volvo D4-300 (1285 hours) loses its fuel prime. About three weeks ago, the engine would immediately start, run for about 1 minute and then cut out. When I attempted to restart the engine, it took several seconds of cranking before the engine would start. It seemed to be starved for fuel. About a week later, the same symptoms happened. This time I used the priming pump on the top of the secondary filter and it took about 35 pumps before there was pump was pressurized. The engine started right away and contiinued to run. The fuel filters on the engine have been routinely replaced, but I decided to replace the filters anyway thinking perhaps I had gotten some bad fuel. When I examined the used filters, there was no sign of crud or water in the fuel filter or the fuel that I drained from the filters. This past weekend the engine started right away, but cut out after about 1 minute. Before starting a second time, I opened the fitting on the top of the secondary filter, and it took about 20 pumps before any diesel came out. Once the air bubbles were purged and I had a steady stream of diesel, I closed the fitting. When I started the engine, it fired-up immediately and did not cut out. There are no traces of leaking diesel from the tank to the filters and to the engine. I discovered online that the rubber priming pump on the top of the filter housing can degrade and air leaks can occur. Does/can this happen and is this a possible cause of the secondary filter to lose its prime? There is some corrosion where the rubber priming pump meets the metal housing. Would an air leak on a fuel line fitting also cause these symptoms? Any trouble-shooting advice would be greatly appreciated before I spend about $500 on a new housing and filter. Thanks.

 

[Bruzer]

Our Ranger Tug, a 2020 R 29 S LE, HIN: US-FMLT2915K920, with a Volvo D4-300 (1285 hours) loses its fuel prime. About three weeks ago, the engine would immediately start, run for about 1 minute and then cut out. When I attempted to restart the engine, it took several seconds of cranking before the engine would start. It seemed to be starved for fuel. About a week later, the same symptoms happened. This time I used the priming pump on the top of the secondary filter and it took about 35 pumps before there was pump was pressurized. The engine started right away and contiinued to run. The fuel filters on the engine have been routinely replaced, but I decided to replace the filters anyway thinking perhaps I had gotten some bad fuel. When I examined the used filters, there was no sign of crud or water in the fuel filter or the fuel that I drained from the filters. This past weekend the engine started right away, but cut out after about 1 minute. Before starting a second time, I opened the fitting on the top of the secondary filter, and it took about 20 pumps before any diesel came out. Once the air bubbles were purged and I had a steady stream of diesel, I closed the fitting. When I started the engine, it fired-up immediately and did not cut out. There are no traces of leaking diesel from the tank to the filters and to the engine. I discovered online that the rubber priming pump on the top of the filter housing can degrade and air leaks can occur. Does/can this happen and is this a possible cause of the secondary filter to lose its prime? There is some corrosion where the rubber priming pump meets the metal housing. Would an air leak on a fuel line fitting also cause these symptoms? Any trouble-shooting advice would be greatly appreciated before I spend about $500 on a new housing and filter. Thanks.

Since I never received a reply from Ask Ranger Tug Factory, I rolled the dice and purchased a new Volvo Penta Secondary fuel filter housing ($531) from D6Parts.com, (sweetgrassdiesel@gmail.com). I received excellent service and advice from them. What I learned from them is that Volvo Penta has had problems with air leaks in the priming pump on top of the housing. The technician said one way to trouble shoot the issue I described above, is to smear grease over the priming bulb. If the engine starts and continues to run, the grease has plugged the holes and stopped the air leaks. This indicates pin hole leaks in the priming bulb and subsequent replacement of the housing with the pump. I also learned that I couldn’t purchase just the filter housing or assembly but had to buy the entire unit, including a new filter, the fuel temperature sensor and the water-in-fuel sensor. The technician asked if I had an evacuation pump, and if I did, I could use that to re-prime the filter instead of manually priming the filter by pumping the bulb 75+ times. I have that pump for oil changes and used it. It took about 3 pumps on the evacuation pump and in about 20-30 seconds had a bubble-free flow of diesel from the bleeder valve. End result: the engine started immediately and runs like a champ. I can’t recommend D6Parts.com highly enough.