Shutting Off Fuel To do Oil Change?

Hey Lads,

I guess I should have read the motor manual before changing my oil for the first time.

I have drained the pan and removed the oil filter and was getting things ready to fill her back up again and the
manual states to NOT fill the oil filter first which is fine but it also says to shut off the fuel and crank the engine.
I know the technique, to build oil pressure in the system before starting but I need to know how to shut the fuel off?
Is there a fuel pump fuse? Damn, is there a fuel pump.............lol.
If not, is there a valve somewhere to shut off the supply?

Sorry if this sounds newb.
Haven't owned a diesel engine in about 25 years.

Caterpillar 275

Cheers
Bernie

I guess thats what the engine manual is for, eay?>>>Dan

Here are pics of the fuel related components on my engine.

There is the water separator, A second fuel filter which I believe has an air purge valve?
If not, is this the fuel shut off valve? It has to lock after use so I assume this is a purge valve, not a fuel shutoff.
Then there is what could be another filter towards the very back. Maybe someone can enlighten me?

The manual I have gives no indication about where the fuel shutoff is, it just says to shut it off

Bernie, so the first pic I see is the Donaldson filter. The drain is on the bottom but the pic shows it on top, lol, please turn if over if the pic is correct. Obviously the clear bowl and drain are supposed to be on the bottom for draining off any water you might find. The second and third pic I see with the knob is your hand priming pump. This is used to prime your fuel filter with fuel after you change it (yes that is a lock for the hand prime). The last pic looks like your secondary filter housing. You usually have two, a primary out back (usually around 20-30 micron, and a secondary close to the engine (usually a 2-4 micron) which will do a final filtration before the fuel goes into your system.
Most mfrs now recommend not filling any filters period. The reason is because most folks don't know the difference between the inlet and outlet side of a filter and they don't want dirty oil or fuel in the system. Yes it is hard on the starter cranking until the fuel system primes (not so tough on the oil filter but still harder than it should be) but way better than putting dirty fuel into your very expensive fuel components (injection pump, etc). So if you don't' want to do it correctly I suggest you install dry filters as they recommend.
If you prime a filter you always do it through the small outside holes so the liquid has to go through the filter (and be cleaned) before it enters the system up through the large hole in the center of the filter. This means plugging the large center filter hole and taking your time as you fill the filter with nothing but the new oil or fuel you are putting in your engine (all the hocus pocus of using other liquids is not necessary). Start with your rig reasonable level and you won't lose a lot of prime back to tank when you remove the fuel filter. The important thing is if you fill your filters do it correct. New oil or fuel in a sealed container is only about class 6 oil (around 25 micron) and your system uses a filter that is around 4 to 10 micron. New oil and fuel in a sealed can is considered dirty for all systems, period.
With your system you can install dry fuel filters and then use your hand prime pump to fill them before you start cranking. It will take quite a bit of pumping and you will develop muscles in your thumb but it does work well. These pumps have a tendency to start leaking around the plunger seal so keep that in mind if you start to have long crank to start problems. 
For your oil filter you can prime it as suggested above or you can locate your fuel shutoff, sorry I cannot remember where yours is located. The newer engines do this electronically, not allowing the engine to start until oil pressure is maintained. If I recall you will have a ball valve up close to the injection pump in the fuel rail if it has not been removed (they were a pain). If you can't see it then call the local dealer with your HEP & arrangement # and they will tell you what they installed for that year.
Do it correctly or do a dry start. Sorry for the length, hope this helps.

The age old way to shut off fuel flow is to clamp Vise Grips on the [flexible] fuel line. But diesels have a fuel shutoff solenoid somewhere - that's how they engine gets shut down when the key is turned off. If you can find it in the fuel line, just remove power there. Might even find a chassis fuse labeled for it.

Frankly, I wouldn't bother. Slow-cranking the engine to pump oil into the dry filter is no doubt the best practice, but for most diesel RVs an oil filter change is only a once a year operation, so just firing up the engine does the job with negligible wear & tear. We are talking only a couple seconds to push oil through the filter and chances are the engine hasn't even fired yet if it was cold when you do that. The purists will no doubt scream that it's a terrible way to treat an expensive diesel engine, but I just can't get too alarmed about such a short and infrequent event.

Mavarick said:

  [clip] The newer engines do this electronically, not allowing the engine to start until oil pressure is maintained. [clip]

Click to expand...

My Cat C9 manual states that the injection pump will not allow the engine to start until the oil pressure is adequate. So, no problem with a dry start. Other engines may have this same feature.

Ken

Thanks Lads,

I have gotten it from a number of people now to not worry about starting the engine before the oil filter has filled up.
I guess if it was a big deal, someone would be screaming not to do it.

I used to own a Porsche 928 and if you didn't build oil pressure before starting the engine it would clatter in the heads for a couple of seconds and that
didn't sound very good. I always removed the fuel pump relay on that one to crank until I reached oil pressure and then reinstall the relay. Hence my
concern about a dry start on the diesel engine.

If I can find a valve or solenoid today I will close it or disconnect it.
If not, I will go for the dry start with fingers crossed that either something will prevent a start until oil pressure is achieved or that it only takes a second or two
for the system to build pressure.

Sorry the one pic was upside down.
Yes, the water separator has its visible bowl on the bottom............lol

After this I am taking it to a RV shop to have the fuel filters changed and get a general once over on the air brakes, chassis and any other service items that
I have to deal with. No doubt I will gain a lot of experience from the first go through with the mechanic.

Thanks guys,
I will check this post again before I finish this today for one last round of opinions.

Bernie

I have a Continental LDT 465 in my M35a2 and it takes 10 to 15 seconds to get its oil pressure up. Everyone of them do it every time, always have the pressure lag. It doesn't seem to harm them since they run forever (mine is a 1971) . Just for those that don't know what on is, here is a pic.

You can just briefly hit the key several times to get the engine to turn over for a bit without actually starting. Oil will begin to flow and fill the filter, so it doesn't clatter as long when it does start.

Maybe the Cat is more sensitive to oiling, but I can hardly tell the difference on my Cummins ISL when the filter is dry.  There is little difference in noise and it's only a couple seconds.