The main moving part inside most suction pumps is the diaphragm, which is on the end of the rod going backwards and forwards. Because they are moving parts, they damage more easily.

If the diaphragm is damaged, the pump will not suction properly. On the Aspiret pump, you can see the diaphragm here.

In this video, we show you how to replace the diaphragm after the pump assembly has been taken apart for cleaning. However, you do not need to take the pump apart if the only thing required is to check or replace the diaphragm.

As you can see, you could easily access the diaphragm with the whole pump assembly still in place.

To access the diaphragm, first detach the moving mechanism from the rest of the pump assembly.

Using an Allen key, loosen and remove the small screw inside the brass piece.

Once the screw has been removed, slide the brass piece off the shaft. To prevent the screw from getting lost, thread it back into the brass piece for safekeeping.

The orange rubber part at the end of the diaphragm should not have any damage. It can be removed from the diaphragm for inspection.

To remove it, undo the Phillips screw and take off the piece that holds the orange rubber in place. The orange rubber can then be removed.

If the orange rubber shows any signs of damage, it should be replaced. This one is still in good condition, so it can be fitted back into position.

Make sure the orange rubber is installed the correct way around.

Then refit the screw to secure it in place.

Now you can refit the diaphragm by gently sliding it back into the pump housing. You do not want to push it back in straight like this, because otherwise you will damage it. Instead, you have to put it back at an angle like this. Gently rotate the diaphragm as you push it into the housing. It is very delicate, so you must not force it in, otherwise, you will damage it and the pump will leak. Once the diaphragm is positioned correctly, you can then replace the brass piece.

The other part you may need to check and replace if it is damaged is the rubber gasket behind the entry and exit nozzles.

First, use a permanent marker to mark the nozzle unit so it can be reassembled the correct way around.

To access the gasket inside the nozzle unit, undo the four screws.

Now take the unit out of the frame and you can put that one to one side.

You can then open the unit up. Inside, you will find the rubber gasket.

You can use tweezer pliers to gently remove the gasket for inspection. If there is any sign of damage, the gasket needs to be replaced.

Before refitting the gasket, clean the area where the gasket sits and the inside of the nozzle unit using cotton and alcohol. When putting the gasket back, make sure the two small guide holes line up so it is fitted the correct way around.

Finally, reassemble the pump assembly.