Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

Oscarklemo · 2025-06-20 17:18:49

As I'm changing glow plugs, I thought I'd try to refit the original fuel filter.

I started taking the original filter casing off to change the O ring underneath. Then I found this part.

What does the fuel filter housing sit on? Seems it's connected to the cooler in some way? Is it som sort of pre heater? And why the grooves/maze? The same pattern appears under the fuel filter casing.

Oscarklemo · 2025-06-20 19:13:12

Where does the fuel line from the primer pump go?

I'm thinking it should go directly to the lower connector on the fuel filter housing? Or does it go on the top connector?

I csnt figure it out from the picture.

RegW · 2025-06-20 22:06:36

I'd say Top of filter/outlet (no 4) goes to injector Pump/inlet (7) which, if I'm right,
should currently be connected to the bottom of your after market can filter.
8 on pump should be the fuel return to tank.

By all means check though, because I have a different pump and filter on my 2.0 HDI.

RegW · 2025-06-20 22:14:45

BTW the standard filter setup does look very much like a heat exchanger to warm the fuel
which will have some ability to cool it as well, odd as this may sound

Diesel likes to be warm but not hot, so as the coolant will or should be, kept within a temperature band close to say 85/90C
so if the fuel has been circulating on long, hot, journey it could be cooled at least in theory by coming into contact with
something relatively cooler on its way to the injector pump.

It's to do with heat expanding the volume of the fuel so
the same amount will take up more volume in the pump when hot than when cold/cooler
so produce less power per volumetric dose

Some ECUs can adjust for this variation but yours may not.

Last edited by RegW (2025-06-20 22:23:00)

kenbw2 · 2025-06-21 04:29:18

RegW wrote:

BTW the standard filter setup does look very much like a heat exchanger to warm the fuel
which will have some ability to cool it as well, odd as this may sound

This is exactly what it's for, good for prewarming on veg oil

RegW wrote:

Some ECUs can adjust for this variation but yours may not.

It definitely won't on the ECU-less XUD9

RegW · 2025-06-21 11:51:43

Ah! hang on
Another look tells me the outlet from the filter goes to the priming pump then the injector pump
I mistakenly assumed the primer was pre filter, so 7 (pump inlet) must connect to the primer.

What are two sensor looking connectors? one green one blue.
I'll guess one is the coolant temp sensor.

Last edited by RegW (2025-06-21 11:56:02)

kenbw2 · 2025-06-21 15:11:43

RegW wrote:

What are two sensor looking connectors? one green one blue.
I'll guess one is the coolant temp sensor.

Yea, I believe at least one of them controls when the fan comes on. The thermostat is in that housing

RegW · 2025-06-21 16:40:52

Ahh! yes of course, the old thermo switch thingy

Oscarklemo · 2025-06-21 20:13:09

Ive now fitted it as priming pump-> fuel filter inlet (bottom connection) and the fuel filter outlet (top connection) to injection pump.

Right or wrong, it does work.

I don't think the primer pump should be between the filter and injector.

@KenBw: you have the same motor, don't ya? Can you double check?

Ive driven around 20km with it with this setup. If I've connected it wrong surely it wouldn't run...

Oscarklemo · 2025-06-21 21:04:26

Found this diagram for snother car but with the same motor.

Here its connected as i did.

Edit: Its mirrored to reality

Last edited by Oscarklemo (2025-06-21 21:06:57)

kenbw2 · 2025-06-22 01:38:46

This is mine:

tank -> priming bulb -> filter -> pump

RegW · 2025-06-22 10:58:51

Doh! I'm so friggin stupid
I kept looking at that orange knob thing thinking it was a priming pump
and ignoring the squeezy ball thing.
Of course! the orange knob is the dip stick and nowt to do with fuel system?

Sorry for any confusion caused by my chiming in half assed.
My van has the DW10 HDI so different sytem and its been many years and vehicles since I had the Citroen C15
that had a DW8 or XUD ( not sure) and its a vague memory now.

Glad you got there despite my 'advice'

kenbw2 · 2025-06-22 14:02:22

RegW wrote:

I kept looking at that orange knob thing thinking it was a priming pump
and ignoring the squeezy ball thing.

Yea on these engines it's a bit of an addon. I did like the DW8's integral priming pump. The flimsy lid clip less so

RegW wrote:

The orange knob is the dip stick and nowt to do with fuel system?

Yep. And it screws off for the oil filler too

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#1 2025-06-20 17:18:49

Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

#2 2025-06-20 19:13:12

Re: Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

#3 2025-06-20 22:06:36

Re: Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

#4 2025-06-20 22:14:45

Re: Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

#5 2025-06-21 04:29:18

Re: Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

#6 2025-06-21 11:51:43

Re: Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

#7 2025-06-21 15:11:43

Re: Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

#8 2025-06-21 16:40:52

Re: Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

#9 2025-06-21 20:13:09

Re: Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

#10 2025-06-21 21:04:26

Re: Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

#11 2025-06-22 01:38:46

Re: Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

#12 2025-06-22 10:58:51

Re: Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

#13 2025-06-22 14:02:22

Re: Refitting Original fuel filter Citroen Jumpy 1998 XUD9 TE

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