Thread: Installing an AUX Fuel Filter/Primer under the bonnet of a Puma Defender...

Originally Posted by Robmacca

Hey Guys...
Ever since I had fuel issues while out in the desert last year, I've been wanting to install a Aux Fuel Filter/Primer on my Puma. I know of ones that mount to the inside of the chassis above the G'Box Support bracket but this I wasn't keen on...

I've found a German made Mann Hummel Aux Fuel Filter/Primer that will fit in the engine bay. I made the necessary brackets to mount it and then had to search the web for the appropriate Fuel Line Quick-Fit connectors... After a failure to source these locally and then buying the wrong size off eBay I eventually found and bought the right quick-fit connections and installed and plumbed in the Filter. I primed it and started it and left it idling for 15mins or so w/o problems. Next will be to go for a bit of a drive to make sure all is working fine.
The filter is a 3micron Filter, so I'm unsure if the flow rate will be enough or not... I'm hoping so. Its so much nicer having a primer up at the engine end when having to change the OEM filter down the rear of the vehicle... anyhow, time will tell on whether this continues to work w/o issues. I've made it in such a way that I can return it to factory simply by disconnecting the Aux Plumbing and re-connect the original fittings together...
Pics below...

Nice. Do you know how the flow rate compares with the OEM filter? Is it finer?

Originally Posted by DiscoMick

Nice. Do you know how the flow rate compares with the OEM filter? Is it finer?

That's one of my concerns.... its right on the limit with the 3micron filter. The kit did come with a 9micron rated filter but as the OEM is 5, I wanted something smaller. Having seen inside the Mann Hummel Filters, their quality is quite good so if the 3 micron rated filter doesn't perform, than I'll just have to fall back to the 9 which has a suitable flow rate.

I'll have to take it for a bit of a hard drive up a mountain range to see if there will be any performance limitations, but hopefully all will be good

Nice work Rob

I’ve written it up on AULro and mentioned numerous times but in also installed a 12V primer / water trap with alarm and filter in my 2.4L tdci

I went with a Parker/Racor marine unit

I installed it before the factory unit as racor filter elements are 1/4 the price of OEM unit
I have the option of 2-5-10 micron and have since install been running a 5 micron (2 years now)

I too was worried if the fuel pump would have issues drawing through two filters (I’ve had no problems)

And I agree having a primer switch is a dream for fuel system maintenance.

S