Priming a fuel filter after changing it

Priming a fuel filter after changing it

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StillLearning

Original Poster:

21 posts

49 months

Sunday 28th March 2021
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I'm changing the fuel filter on a Peugeot 207 HDi, but I am struggling to prime it. The bulb doesn't seem to be working so I want to use a vacuum brake bleeder to get the fuel through.
Which hose on the top of the filter do I want to attach the bleeder to?


mercedeslimos

1,657 posts

170 months

Sunday 28th March 2021
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You need to bleed from the tank return if you can figure that one out

Chris32345

2,086 posts

63 months

Sunday 28th March 2021
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I really don't know why manufacturers use systems like this instead of a self priming type with a in take pump

I guess to save £3 on the pump in production

mercedeslimos

1,657 posts

170 months

Sunday 28th March 2021
quotequote all
I'm lucky that my 2.0 HDi has a keyless start button which will crank until it fires. I believe the one with the key is a lot more problematic. I found that filling the filter manually (pipe and funnel) can help a lot too.

StillLearning

Original Poster:

21 posts

49 months

Sunday 28th March 2021
quotequote all
mercedeslimos said:
You need to bleed from the tank return if you can figure that one out
From the return to the tank? I'm having total confusion - I'd googled it and seem to get different views, some people say bleed the return, some the inlet?? I can't work out if people are just using different terms for the same hose! I basically want to just make sure the filter is full of fuel.

mercedeslimos

1,657 posts

170 months

Sunday 28th March 2021
quotequote all
StillLearning said:
From the return to the tank? I'm having total confusion - I'd googled it and seem to get different views, some people say bleed the return, some the inlet?? I can't work out if people are just using different terms for the same hose! I basically want to just make sure the filter is full of fuel.
In real terms the fuel system goes:


Tank > Filter> Pump > Filter > Tank

You want it at the fourth arrow in that flowchart, after the second filtration, and before it goes back to the tank. That way you stand a chance of getting all the air out, or as much as the high-pressure pump will be able to get the engine started without air locking.

It's a common rail diesel, no matter what engine the theory is the same. You're lucky it's not a Ford 1.8 TDCi, those seem to be absolute pigs and need every last drop of air gone.

Athlon

5,018 posts

207 months

Sunday 28th March 2021
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That should self prime, ignition on for ten seconds, repeat five times and it should fire up no problem

bungz

1,960 posts

121 months

Wednesday 31st March 2021
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Those filter housings are a royal pain.

Its the one with the odd canister that bolts on with a odd shaped seal? Utter crap design.

If so the little priming bulb (the button thingy) works perfectly when you get it sealed correctly.

No seal no prime.