Thread: Air bubbles after the filter of TD5

my defender won`t start anymore. this is a TD5. i hooked up some transparent tubes before(low pressure feed to the filter head) the fuel filter and after it too. low pressure feed line to the filter is very clean without any air bubble. But the return line from the fuel filter(low pressure)which is going to the pump is full with air bubbles. Note : I have removed the return line from the engine and air tied the union which is relevant to that in fuel filter head. That return line hooked up to a basket.
How is the air bubbles getting in, after the fuel filter. checked the filter gasket, even fitted a new filter and also checked the drain plug in bottom of the filter. and also the air bleed valve is okay. don`t know how to test it, diesel is not coming out. so my guess is that`s a good one.
Pump is noisy. changing pitch according to the air bubbles which i see after the filter (output of the low pressure line from filter to the pump).
When i directly connect the hose coming from the pump (low pressure feed) to the pump again(i mean without going through out the filter), no sound at all + not a single air bubble. And engine runs without a hassle.


Thank you. any help would be appreciated please.

Before trying a new pump, dismantle the fitting on the return side of the fuel pump to the tank
Here is the link to the service bulletin.


[ame]http://gershon.ucoz.com/landrover/TD5/TOPIx-LD310-001-Defender_Td5_Poor_Starting_Noisy_F.pdf[/ame]


Even if the "O" ring is intact, you should get a very minor flow of air if you blow through it.


Took me 2 fuel pumps - I Bearmach & now a VDO b4 I found the cause of very difficult starting. Probably need a new starter next..