Diesel Under Bonnet Fuel Pump ( Replacement ) by Arctic

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Those of us whom have a diesel R40 and a under bonnet fuel pump know that at some time this may need changing, hopefully this thread will help you to do that for your self.

Through out this post the under bonnet fuel pump will be referred to as(UBFP)always purchase the best one you can which is most certainly the Pierburg in my opinion.

The tool you will need are 13mm ring spanner, 8mm socket, T40 torx, a small screw driver and a medium screw driver flat blade, and a couple of jubilee clips.

First you need to start by removing the battery lid,then securing strap 13mm ring spanner in this case, unless you have the lower bolt which is on some models, in that case it would be a 10mm socket Fig 1

Next remove the battery terminals 13mm spanner Fig 2/3


Lift and remove the battery from it's tray Fig 4

With the battery removed from the tray you can then see and undo the four torx bolts holding the tray in place, use the T40 torx socket bit or tool which ever you have, Fig 5

Remove the tray and it's metal bottom plate, set it down with the battery close by on the floor Fig 6

You can now see the main plate the battery box is fitted to, remove any other wiring clipped to the main plate around it's sides Fig 7

Attached to this is the UBFP as pointed out here below Fig 8

The pump is secured to the main plate by a bracket which is held by a single 8mm bolt Fig 9

This bolt can now be removed using the 8mm socket so the bracket can be released Fig 10

The bracket as a T fixing joint that slots in to the plate opposite the bolt Fig 11

Now unplug the wiring from the top of the UBFP by pressing the tab on the wiring plug Fig 12/13


With the wiring plug set out of the way release the servo pipe/tube from it's brackets this just give that extra little bit of room when removing the UBFP later. Fig 14/15


Follow the pipe further back toward the service and unclick at least three joints Fig 16

Now the wiring and the servo pipe as been removed and out of the way the main plate will pull toward you, again make sure no other wires are clipped the plate Fig 17

With the main plate pulled towards you a little you gain more access so you can remove the UBFP bracket from the plate Fig 18/19


Put the bracket safe on the engine cover or with the battery and it's tray Fig 20

The UBFP is now free and can be move about a little but try not to twist it to much as you may damage the T joint below the UBFP fig 21

Place a couple of old rags under this joint and over the ABS (Antilock Braking System) module Fig 22

Next release the fuel pipe going into the low pressure pump on top the fuel filter, before releasing put a rag under the joint, press in the two side clips to remove Fig 23

With the fuel pipe removed from the low pressure pump you can gain more access to the bottom jubilee clip holding the UBFP to the fuel line at the T junction Fig 24

Using the small screw driver slot the end into the square hole on the clip and twist the screw driver the clip will come undone Fig 25/26


The UBFP pump should now twist out of the pipe try this slowly and carefully if it is stiff use the end of the small screw driver to prise the rubber pipe down a little to help release it. Fig 26

Remove the UBFP out of the way making sure you do not spill any diesel fuel, if you do clean it up right away, clean working area and all that, Fig 27

Make sure you have your couple of jubilee clips close to hand, ie on the engine cover for refitting of the new UBFP Fig 28

As you can see from the photo the top fuel hose is already attached so I will only need one jubilee clip in this case for refitting Fig 29

You can now add the jubilee clip to the fuel pipe, push the new UBFP into the fuel pipe T junction and fit and tighten up the jubilee clip securing the UBFP at the bottom, using the medium screw driver Fig 30

Fit the bracket round the UBFP Fig 31

Push the top UBFP hose into the low pressure pump Fig 32

Fix the bracket to the main plate using the 8mm bolts removed earlier Fig 33/34


Re fix/clip any other wiring removed from the main plate earlier Fig 35

Line up the main plate with the securing holes and then fit the battery box and inner plate into position using the four T40 torx bolts Fig 36

Replace the battery and it's securing strap Fig 37

Fit the positive and negative terminal to the battery, remembering to open the the ends with the medium screw driver so that the terminal will tighten up nicely once fitted Fig 38/39


Only nip up the nuts on the terminal to tighten if you do them up to tight they will only work loose due to the taper on the battery poles Fig 40/41



Link to battery terminals and how to fix cheers Arctic.

Posted 03 Apr 2016, 19:12 #1 

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Fitted another one yesterday on my sons car after we sourced a good used Pierburg one, which we tested off the car before hand, it had a good flow rate and was nice and silent compared to the aftermarket one fitted which was loud, once fitted he was glad not to have buzzing Bee effect 0

We managed to source 5 of these used Pierburg pumps in good order and with great flow rate


https://www.amazon.co.uk/Pierburg-7-500 ... f_lc&tag=_

Posted 01 May 2016, 09:34 #2 

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Creeing Jane
Keep an eye for corrosion on the bolts at the base of the battery box. Mine had gone from a leaky battery and so getting access to the pump was a royal pain.
2002 Zircon Conn SE CTD Auto Tourer
1972 Triumph Stag MOD TV8

Posted 27 Sep 2016, 19:15 #3