Mechanical fuel pump replacement

Mechanical fuel pump replacement – main image

Older vehicles powered by carburetors were equipped with mechanical diaphragm pumps, which, unfortunately, fail quite often. The most common problem is a leaky diaphragm and worn valves.

Fortunately, there is no problem with purchasing such a pump and replacing it. We can buy on, the first international trading platform , thanks to which we can browse the database of free-of-charge purchase and sale ads for used car parts.

In popular cars, diaphragm pumps are usually mounted with two bolts or pins. In order for us to replace the pump, we have to unscrew it, but before we do it, we should secure the pipes so that no fuel spills out. For this purpose, we can use wrenches and simply tighten the hoses.

Before clamping the hoses, remove the clamps that hold the hoses on the pump. If these clamps are disposable, they can be easily broken, but if worm clamps are used, they must be unscrewed using a screwdriver or a wrench if there is access. Then select the appropriate wrench, unscrew and remove the bolts securing the pump to the body of the drive unit.

The next step is to gently pull the pump out. Remember that there is a thermal gear between the motor body and the pump, which in most cases can be removed with the pump. Place the pump in a vessel because it contains fuel remnants that will undoubtedly leak. The next step is to separate the spacer from the pump, at the same time we can remove the remains of the gaskets in such a way that the surface is clean.

Then clean the surface of the pump attachment to the drive unit body. Remember to pay attention during this operation, not to remove the pusher, which is to be located in the body, without the pusher, the pump will not be able to function.

At this point, we can already put gaskets between the body and the spacer, as well as between the spacer and the pump. It is important that the seals are new, otherwise oil leakage will occur. The seals should be replaced every time as they are disposable.

Before installing a new pump, we should check that all the screws have been tightened properly, as it sometimes happens that they are loose. Now all you have to do is put on the pump, put the screws back in place, remembering that you should not use too much force, because tightened screws will deform the pump, which will result in leaks. The next step is to put on the hose clamps and put the hoses on the pump cocks. We can now take the french fries off the hoses and tighten the clamps one by one.

Once everything is installed, we can start the engine. Remember that the pump is dry and therefore the engine may not start immediately. After starting the motor, check if there is a tight connection between the pump and the body and the fuel hoses.


The main driver, founder and the brain of CampRest. He is the one who runs the whole mechanism, implements new ideas faster than he is able to invent them. He used to be a professional driver and have run his own freight forward company - as you can see, he has always been drawn to sleep in the car;) He likes to drive large motorhomes and encourages you to get a C driving license and buy motorhomes over 3.5 tons.

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