Draining Fuel Filters

[qayqayt]

It's time to service our coach for the first time.  The fuel filters are the "sock" type.  The manual says that I should be draining the fuel filters on a regular basis to prevent water from getting into the system.  If I do this, does the system draw fuel from the tank or should I add fuel at the filter?

When changing out the filters, the manual says I should drain the filters first, then remove them.

I'm worried about losing the prime on the engine.  I was going to remove the filter covers full of fuel, dump them, change out the sock filter then refill with fresh diesel and re-install them.

Any advice other that switching to "spin-on" filters?

Bryan
Vancouver BC

[Don4107]

Look here for some good info on how to make it easy.

http://www.busconversions.com/bbs/index.php?topic=12705.0

Don 4107

[DaveG]

Draining the fuel filters is nothing more than opening the petcock on the bottom of the canister or removing the plug, letting a little fuel/water out...maybe 1/4 cup or so. Just drain the water out, if no water then stop draining. Letting that little bit of liquid out should not require priming, but may require some throttle on startup to keep it running until the gear pump fills things back up.

As far as changing sock filters, I would make it a practice to fill the canisters up with fresh fuel, but should not need pressure priming.

[gus]

I learned the hard way not to drain more than an ounce or so at a time.

If there is no water, stop. (As Dave said)

If you find water run the engine, let it burp, and drain another ounce. It will handle this at a slightly fast idle if you don't drain too much.

[qayqayt]

Yikes... sounds like a real touch is required.  Thanks guys, this is a huge help.  Should I just drain at the primary filter or should I do both?

Bryan
Vancouver BC

[DaveG]

You should drain the primary first, if water is found...do as above. You can drain secondary, but the water will usually get trapped in the primary so the secondary will usually not see any. Again, your experience will dictate what needs to be done. If you always find water in the primary, keep draining it. If you never find water in the secondary...don't drain it anymore.

Here I am refering the the primary as the filter before the transfer pump, and secondary as the filter between the pump and the heads/injectors.