| Author | Message | ||
| Don/TX
Rating: N/A |
It has always seemed to me that diesel filters are often changed needlessly, simply because there is no pressure differential gages installed on buses. I think we can all agree that the filter needes to be changed when it gets dirty, which can occur anyplace from an hour to a year of running. Has anyone installed either a gage with valves or two gages to monitor differential pressure before and after filters on their bus? | ||
| Gary Stadler (Boogiethecat)
Rating: N/A |
Hi Don, My guess is that it would take a hard-to-find gauge... at least my main filter is on the suction side of things, and while there may be a lot of flow, I doubt there's much pressure differential even if the filter is clogged, because the gear pump can't "suck" much before it looses it... But then my system might be a lot different that others. If you were to put a gauge on a system like mine, I'd think a differential vacuum gauge would be what you're looking for... not a comon doodah even on ebay... It also occurs to me that if you keep the filter maintained and your fuel tank clean, it's a non-issue. I've never had a filter plug on me except when someone dumped dirt into my Bobcat fuel tank (an idiot dealer, changing the sender) Isn't it simpler to just wait it out until the filter plugs, then change it? Seems that's what most of us do (me for sure)... simple, cheap, effective... you do have a primimg pump, right...?  | ||
| Don/TX
Rating: N/A |
Well, I have had the misfortune twice to fill up with a bad batch of diesel fuel, and headaches from that start quickly. Several filter changes in a thousand miles or so, keeps clogging up. I would assume that if you had a gauge on the output side of the lift pump, pressure would drop if the primary was clogging, and the differential across the secondary would also tell you the status of it. I know there is a switch made to turn on a light when the differential is too much. | ||
| Geoff (Geoff)
Rating: N/A |
All you need is a fuel pressure gauge on the secondary filter-- with new filters it should read 60 psi, as the filters get plugged up the pressure reading goes down. Since we have buses with dashes that are 30-35 feet away from the engine, an electric pressure gauge with a sending unit at the secondary filter would work the best. And it doesn't have to be a specific "fuel pressure gauge", an electric oil pressure gauge would work just as good minus the word"fuel" on the gauge. --Geoff '82 RTS AZ | ||
| Don/TX
Rating: N/A |
I had thought of that Geoff, the only disadvantage would be that when the pressure dropped, you would have to guess if it is the filter, the guage, or the pump, obviously the odds are in favor of the filter. Plus, don't pressure vary with temperature of the diesel fuel etc? That system did work well on the 3406 Cat though, you sure could tell when it was time to change filters. | ||
| Geoff (Geoff)
Rating: N/A |
The fuel pressure gauge is common on Cat engines, but I remember seeing the same setup as I described on Detroit engines in trucks back in the 80's. | ||
| joel
Rating: N/A |
DD markets a fuel filter assembly with a clear cover which gives a visual indication of the need to change the filter element. I have spent a lot less on filter changes since acquiring the new type filter. The clear cover is plastic/acrylic something, so be somewhat careful re mounting near a heat source. | ||
| Richard Bowyer (Drivingmisslazy)
Rating: N/A |
Don, DML has a fuel pressure guage as Geoff describes. At idle it is very low, around ten pounds as I recall, but up to operating speed it stayed right on 60 lbs., hot or cold. As soon as it started to drop any below that I changed the filter. Granted it could have possibly been something else, but in my case it was always the filter. Richard | ||
| Larry & Lynne Dixon (Larry_d)
Rating: N/A |
I had an 84 Bluebird Wonderlodge, it had some kind of gauge that measured lbs of pressure for the filters. I thot it was run by vacume some how. Was quite handy until I change system to a new Fuel Pro, (very good system) for under $500. For what this is worth 4905 larry | ||
| FAST FRED Rating: N/A |
Murphy Gage makes exactally what you want , with an alarm too if needed. Some marine filters have a simple vacume gage that screws on the center bolt .Raycor The DP gage IS the way to go, as the Raycor is direct reading. Many many hassles can be avoided by simply installing an "Armoured Sight Gage" from your local refrigeration supply in the fuel line.. Bubbles is bad . FAST FRED | ||
| Jim Shepherd (Rv_safetyman)
Rating: N/A |
I used to attend every seminar that Mike Meloche (now retired from Detroit Diesel) put on at the MAK rallies. Mike was a wealth of knowledge and a straight shooter. He was always asked about additives (fuel and oil) and always said that HE (and DD) did not believe in them. He was also asked about accessories and the only one that he said was absolutely worth the money was the Fuel Pro 382. With the Fuel Pro (http://www.davcotec.com/fp382.htm) you can see when you need to change the filter. You can also see problems with the fuel such as contamination and air. It also can be used to prime the engine. It is mounted fairly high (above the fuel level in the tank) and has a cap that can be removed to add fuel into the “bowl”. With that fuel, the engine will almost always start. Once in a while you will need to repeat the procedure, but it is fool proof and easy – don’t need an electric pump in the system. The Fuel Pro replaces both the primary and secondary filters, thus becoming the only fuel filter in the system. As noted above, it “tells” you very graphically when it needs to be changed. Since there are no other filters, there is no need to worry about having to fill the filters and loose prime. The units are a bit pricey. The 12V heater unit is over $200 as I recall. I have looked at a bunch of trucks over the past year, and every one I see has a Fuel Pro on it. I would not run my bus without one! Jim Shepherd Evergreen, CO ’85 Eagle 10 http://rvsafetysystems.com Bus Project details: http://www.rvsafetysystems.com/busproject.htm (updated 2/17/05) | ||
| Don/TX
Rating: N/A |
That does look like a great system Jim, solves lots of problems (still no pressure guage though). I see an unheated one on that auction site too. Anybody had any bad luck with one of these? | ||
| Sammy (Sammy)
Rating: N/A |
The Fuel Pro is the way to go. Very easy to tell what's happening, very easy to prime the fuel system too.There's a special wrench that goes over the plastic bowl to turn the lock ring.Consider buying one of these too. |