How to clean fuel pump filters?

How to clean fuel pump filters?

Knowing how to clean fuel pump filters is as important as basic car skills like changing engine oil, replacing fuses, testing the battery, etc. Whether it’s cleaning the filter in an SU electric pump simply using a brush or the red flags that indicate your fuel pump filter has been clogged, read this article to know everything about cleaning fuel pump filters.

What is a fuel pump filter?

 Attached to the fuel pump, a fuel pump filter is a filter that belongs to the mechanical fuel pump assembly. Unlike fuel filters with fuel injection, a fuel pump is often replaced only in extreme circumstances.

Common signs of a clogged fuel pump filter.

Following are some of the most common symptoms of a clogged fuel pump. Either learn how to clean fuel pump filters or reach out to a mechanic if these symptoms reoccur.

How to clean fuel-pump filters

Now, let’s first cover the basics of knowing how to clean fuel pump filters. Your car’s engine will either stop working or cut out from time to time at high speeds if it has a blocked fuel pump filter. However, every car doesn’t come with a filter in its pump. Many contemporary car models come with filter less and sealed pumps that do not require regular maintenance. They have filters fixed in their petrol tanks, fuel pipes, or carburetor.  

In addition, some cars come with mechanical fuel pumps. Placed on the engine’s side are these pumps. However, if you can’t find them, you can trace them from the carburetor. If the fuel pipe leads in the fuel tank’s direction, then your car most probably has an electric fuel pump.

Before you start servicing the electric pump, make sure to disconnect the battery. Be very careful while doing this as a fire may erupt in case of an accidental spark due to the spilled petrol. Now, use fresh petrol to clean filters. Use a lint-free rag, clean the pump’s insides, and ensure the sealing gaskets are functioning effectively. If the gaskets are showing signs of trouble, replace them.

Above the sealing washer, you may find a fixing screw. While adjusting the screw, do not overtighten it. Over tightening will either cause pump damage or make it leaky. Furthermore, there are several electric pumps that are licensed copies or SU. To clean the filter, it’s imperative to remove them regardless of their awkward positions. Lastly, to stop the oil leak from the disconnected pipes, use rubber bungs or old pencils.


Most mechanical pumps have filters fitted.

These days, many mechanical pumps come with a covering filter at the top, which is removable. In previous models, you’ll find a glass dome at the top. Holding the top is a nut or a central screw. Firstly, unscrew the nut or central screw. Then, take out the filter by lifting the top. Don’t touch the flexible fuel pipe if you find it connected to refit it the right way later.

Few pumps come with a cylindrical filter that is connected to the cover. You can easily screw it into the pump using bare hands. Furthermore, there are a few pumps that come with crimped-on pipe clips. Use side cutters to cut them. If the pump is detached, replace it using a screw clip.

SU electric pumps

You’ll find outlet nozzles and two dome-shaped inlets in the majority of SU electric pumps. They are placed side by side, going in opposite directions and are composed of black plastic. Check the casing to figure out which is the inlet and which one is the outlet. Then, remove the inlet nozzle only. Do the job quickly as the rubber sealing beneath the inlet starts swelling when exposed to air.

Clean the filter using fresh petrol and a small paintbrush instead of removing it completely. However, make sure that the brush has no loose bristle. Finally, fit the nozzle back again.

Earlier models of SU pumps come with screw-in connections placed at right angles to each other. In these models, placed beneath a brass-headed cap and opposite the outlet towards the carburetor is the filter.

You will find two additional SU electric pumps in big cars. Their SU electric pumps will have an outlet and inlet placed side by side. One of them will have a double electromagnet. Remove this electromagnet to access the filter. Only remove the cylinder placed on the right in this type of SU electric pump. Separate the base and cylinder by unscrewing all six screws.

Furthermore, there will be two additional screws holding the metals plates. Unscrew those two screws, too and take the valve and inlet valve cover out. In addition, you will find a small gauze disc and a filter placed underneath. Use a pin to gently take it out.  

Now, properly reassemble the pump. For the pump to work properly, the gasket should stay in its position. Lastly, refit both the electrical connections and the pump and connect the fuel pipes again.

SU mechanical-pump filter

You will mostly find the SU mechanical-pump filter installed in British cars. This pump is a tad different from other pumps and comes in two different types. These two types are AUF 800 and AUF 700. The AUF 800 comes with a filter, while the AUF 700 does not, but it comes with a removable top.

 Placed side by side but leading in different directions is the outlet pipes in AUF 800. Fixed using two screws, a metal ring is used to hold the elbow connectors in place.  Made using soft metal, these screws have been tightly screwed in.

Now, lift the inlet and filter and also remove the ring. Lastly, clean and reassemble as quickly to avoid the pump elbow from swelling.


A clogged fuel pump filter isn’t just detrimental to your car’s engine’s health, but it’ll also create several recurring problems for you. Thus, knowing how to clean fuel pump filters on your own is the only long-term and viable solution for this issue.