J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Diesel problems

RII is correct
you have to push the lift pump lever beyond the first point of resistance,...you may have to rotate the crank shaft to ensure free movement of the pump / cam


According to diesel mechanics, all rubber components in the fuel system should be changed every seven years or so,...the lift pump diaphram is rubber and does deteriorate with time

If you change the pump I would also get new copper washers at the banjo fittings

Hom complicated of a job is it to change out the lift pump?

And, I was unaware that crank shaft position was crucial to the operation of the manual lift pump. When I pumped the lever, what little resistance there was was consistent throughout the travel of the lever. The crank may just have been in the wrong position.

Another ignorant question. If I change the primary (Racor) filter, how do I prime that lower part of the system? Will gravity feed from the tank force most of the air through the system so that it bleeds at the secondary filter with help from the lift pump?

Thanks for all of the help.

Changing the lift pump is fairly easy. Two bolts hold it into the stbd side of the block. Inlet is flexible hose on nipple and outlet is steel tubing connected to secondary filter. You want to use a new copper washer on the banjo fitting for that.

on changing the Racor - Gravity will not help as the fuel pickup is from the top of the tank with a tube that extends to the bottom. If you don't have a squeeze bulb or hand pump on the Racor, try removing the vent on top of the Racor and pour in fuel to fill it, then put the vent plug back in. Then open the compression reliefs and have someone turn over the starter while you bleed and vent the system. Once the system is "full", you can use the fuel lift pump to vent the system properly.

The "lift pump" is actually the engine's fuel pump, providing fuel to the high pressure injector pump. A cam moves the diaphragm when the engine is running. When you use the handle, as long as the cam is not in the high position, you move the diaphragm, but if the cam is in just the wrong place, the diaphragm won't move.

The rubber squeeze bulb solution for bleeding is a life saver. I don't know how I would bleed the primary fuel pump without it. (I have a racor without the built in pump.) Just squeeze until fuel comes out the racor's bleed vent. Then bleed the little filter above the lift pump. Run awhile, bleed the little filter again. When you change the racor filter cartridge, be sure to fill it by hand before attaching it to the mount.

When using the squeeze bulb, you can feel whether there is air downstream. If so, you can do a few squeezes before pressure builds. If not, the thing is hard right away. I always worry about squeezing too much, since the low pressure side of the fuel system (in particular the diaphragm in the lift pump) does not expect much pressure.

Good point about changing the lift pump every couple decades. I will go and do it.