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I made this manual in 2015 when Volvo Penta had an overhaul set for this lift pump. Unfortunately, Volvo Penta has stopped supplying the overhaul kit and only a new pump is available for the MD engines. The revision set that Volvo Penta had for the lift pump costs 95.59 euros and for a new lift pump they charge 183.92 euros.
I have a lift pump in my shop that is suitable as an alternative to the Volvo Penta lift pump, but there is no gold rim. The pump currently costs 79.95 and can be found with this link.
If you need a boost pump, you can find the right one for most marine engines via the link.
The lift fuel pump has the function of pumping the fuel under low pressure from the tank to the high-pressure pump.
This pump is driven by the camshaft on small engines.
The feed pump comes in different sizes, but the differences are generally small.
The differences may be in the lid, for example. It can be mounted with a central bolt or with multiple bolts on the edge of the lid. The material of which the membrane is made may also differ.
The orange dotted line on the image is a filter that is washable. This is often a brass plate that must be checked for dirt once a year.
Standard fuel lift pump. Volvo Penta fuel lift pump.
Levers A & B are independent of each other but have a common pivot point.
The mechanism B can only pull down and the spring pushes the membrane up, the spring pushes the membrane up again.
If you want to bleed the fuel system because, for example, you have replaced the (fuel) coarse filter, you can use the booster pump to pump the fuel to the next bleed point, which in most cases is the fine filter.
The priming pump may not work, so the drive cam may be against the operating mechanism. To solve this you have to turn the flywheel a bit, this mechanism will become free and you can operate the pump. If you still do not feel any counter pressure in the lever, it is possible that one of the valves is broken so that the fuel is not pumped up. The diaphragm in the pump may also be torn. If this is the case, you will usually see fuel leaking through the indicator hole in the bottom of the pump.
Below I describe how you can disassemble the pump and replace the diaphragm. The membrane is made of a special piece of rubber and lasts a very long time, 20 years and longer is certainly no exception.
To overhaul the pump you need an overhaul kit. this set contains, among other things, the membrane that cracks after the sale of time, so that the pump no longer works.
Disassemble the pump.
Step 1.
Remove the fuel lift pump from the engine by first removing the fuel lines and then the two Allen screws that secure the pump to the engine.
Step 2.
Loosen the bolt (s) with which the cover, including the filter, is mounted on the pump housing.
Step 3.
Loosen the 6 bolts securing the pump housing to the bottom housing. Then remove the spring attached to the operating lever.
Step 4.
Remove the pin that is the hinge point of the lever with pliers, before doing this, remove the locking bolt on the side of the pump.
Step 5.
Pull the membrane mechanism out of the bottom housing, it is in rubber and can be a bit heavy.
All parts in a row.
If necessary, replace the diaphragm and clean all parts thoroughly with petrol, for example.
Step 6.
Place the diaphragm back into the lower housing and push it in so that you can replace the lever.
Step 7.
Replace the hinge pin and secure it with the bolt you removed earlier.
Step 8.
Replace the spring.
Step 9.
Replace the pump housing and install all 6 bolts.
Step 10.
Replace the filter and then the cover with the bolt. Pay attention to whether the sealing rings are still in good condition, otherwise you may have an air leak, the pump sucks false air and air enters the fuel system.
Step 11.
Replace the supply pump and do not forget to place a gasket between the supply pump and the motor. Then install the fuel lines and bleed the fuel system.
