drkrider Posted October 12, 2010 Report Share Posted October 12, 2010 All the operators I've talked to are having the same problem with the Aux fuel pumps failing every few hundred hours. I've talked with the manufacturer and they tell me the problem is their pumps are a vane type pump with a 2/10th of a thousandth of an inch clearance between the case and the vanes and the factory gascolator on the Raven II's isn't fine enough to stop bits sand etc. from getting in and jamming between the case an the vanes loading up the motor and burning it out. Does any one know of an STC'd inline filter that could be installed? Thanks Sean Quote Link to comment Share on other sites More sharing options...
Heliian Posted October 12, 2010 Report Share Posted October 12, 2010 I haven't seen one out there yet but you think that they would have taken care of the pump reliability issues by now. It's been a year since I had to touch one of those things and I forget whether the gascolator is before or after the pump. The other a/c i work on only have a gravel screen pre-boostpump and still seem to last longer. It's easy for the manufacturer to say it's due to sand or debris in the pump and tight clearances, blah blah blah, it's not me it's you, when in reality the whole a/c was designed to be cheap and disposeable. As for extending the life of the pumps; always use clean filtered fuel, make sure the band clamps are tight, the electrical connections are correct and secure, and don't let the pump run dry. At least the R44 astro doesn't leak hydraulic oil or burn out boost pumps Quote Link to comment Share on other sites More sharing options...
drkrider Posted October 14, 2010 Author Report Share Posted October 14, 2010 I haven't seen one out there yet but you think that they would have taken care of the pump reliability issues by now. It's been a year since I had to touch one of those things and I forget whether the gascolator is before or after the pump. The other a/c i work on only have a gravel screen pre-boostpump and still seem to last longer. It's easy for the manufacturer to say it's due to sand or debris in the pump and tight clearances, blah blah blah, it's not me it's you, when in reality the whole a/c was designed to be cheap and disposeable. As for extending the life of the pumps; always use clean filtered fuel, make sure the band clamps are tight, the electrical connections are correct and secure, and don't let the pump run dry. At least the R44 astro doesn't leak hydraulic oil or burn out boost pumps We fuel out of fuel tanks with filtered fuel 98% of the time, and the other 2% is out of drums with filters on the fueling gear. Also all the lines, clamps, and electrical connections are checked every 50 hours during the 50 hour oil change / spark plug cleaning. The gascolator is up stream of the fuel pump. Weldon (mfg) tells me that the same pumps on fixed wing aircraft make 1200 - 1500 hours no problem it appears to be an R44 II problem. Maybe a weird vibration issue or something. If I find anything else out I'll post. Sean Quote Link to comment Share on other sites More sharing options...
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