Changing fuel filters

[CraneInnovation]

I am looking for tips on changing fuel filters in a Cummins 6BT5.9 on a Gradall with primary and secondary filters. I am new to diesel engines but I know prime is absolutely essential (why not in automotive fuel systems?). I've done some reading and there seems to be disagreement on pre-filling filters or not filling them. There also appears to be a fairly complex set of bleed procedures and references to hand pumps being common on diesel fuel systems. I've bled automotive brakes several times so I'm familiar with how that works.

Anyone had experience with fuel filters on a Gradall? Where would I find the hand pump (if it has one)? Are they fairly straightforward to bleed or is it a science project?

As always, thanks for the advice!

 

[bill onthehill]

I always fill filters with fuel so I don't have to pump that much by hand. The hand pump should be part of the lift pump on the side of the engine. If it does not pump up any pressure you may need to bump the starter to get the cam lobe away from the pump. The actual priming is pretty straight forward. Just loosen the line going to the injector pump and pump by hand till you get good fuel flow. Tighten the fitting and it should fire right up.

 

[Delmer]

I never fill the filters, but if you do, pour fuel only in the outside/unfiltered side of the filter, anything you pour in the center goes straight into the injection pump.

I figure it helps to change the filters when the engine is warm, it starts right back up and has a better chance of pumping enough fuel before it runs out.

There were a couple of different transfer pumps used on 5.9's depending on which injection pump.

 

[willie59]

On the Cummins industrial 6BT, the fuel line from the secondary filter goes to a fitting on the side of the intake manifold. That fitting has a 10mm head bleeder screw. Open that bleed screw, operate the manual primer on the lift pump. As Delmer stated, there were variations of lift pumps used on the 6BT and 4BT, but I've never seen one that didn't have some form of manual pump on the lift pump.

 

[CraneInnovation]

Thanks so much! I'll give it a shot this weekend.

You guys are wealth of knowledge!