Lucas EPIC Injection Pump Overhaul Guide

[Vinyl]

@CitroJim
Thanks but I have just problem to comprehend how only one whole can adjust flow of any fluid

Stop valve, as I recon is a plunger- kind and this makes sense - for two position application plunger is enough

However all 3 other valves regulates pressure of the fuel that later on moves inside of the pump and counter acts to the force of different springs, and I cannot understand how could it be done with a single hole in each of them - this doesn't sound like valve to me, unless there's something I don't know...

[Vinyl]

There's should be at least two wholes in each of them

One incoming fuel
Then solenoid
And then outputted fuel

I don't think I can put this in any clearer words

[CitroJim]

Vinyl, you've got me there... I still can't, and never could, truly get my head around exactly how an EPIC worked even though I was once able to fix them...

It was one of those things I was happy to accept they did work and not worry too much over exactly how...

[moizeau]

Here's a pic I found from when I stripped mine. I thought I may have had a pic of the valve assy split but I haven't.

And here's the rear part with the stop solenoid

And here's a valve

Similarly, how it works??????

[Vinyl]

@Citrojim
No worries here, it still takes a lot of know how to do things you done, and also world would be much better place o
If people were brave enough not to fight for every piece of satisfaction they can get, and to accept and admit their own flows like you did, today's world isn't certainly in favour of cooperation and the latter could be only established through understanding of each other.

As to operation of the pump, see picture below (it's a scan from the transit manual I linked earlier)

There are 3 sections, from the left: transfer pump, high section, cam regulation section

@moizeu
What is the high t of the stroke of these valves? Did you were able to feel it underneath fingers upon dismantle job?

[Vinyl]

The picture:

[Vinyl]

Sry picture here:

[Vinyl]

@moizeu how many orings are to be replaced per one valve? Is it one (wider) on the pump side (pin no 1 and 2 you uploaded) and one on the solenoid/valve side (pic 3)

I think I am onto sth just need little help

[moizeau]

Here's a guide to take the solenoid valves apart
http://citroen.cricou.net/epic/changeme ... vannes.pdf

Here's a manual to strip the pump
http://ludcpt.free.fr/XM/Mecanique/EpicRep.pdf

May not be the same as your's but it will give you an idea.

[Vinyl]

Ok, I think mystery is solved

Your material did not provide any useful explanation for me but what I established so far is enough to present a theory

There are actually two wholes in each valve

Please study the picture I enclose (bottom illustration on the picture) Pay close attention to little "in" and "out" arrows (up and down arrows) BENEATH the valve body (actually beneath and left - where the second arrow is located - to be precise)

These clearly shows flow path ( and also this is reflected in real photo - see 3rd photo by moizeau - whole in the middle is "in" whereas cross-alike structure located behind the seal is "out of the valve" terminal.

Also on the pump side ( pic 1&2 by mozieau) you can see for each valve 2 wholes
one whole in the middle
one few mm apart from that one in the middle - this one enable those cross alike structures from the valve side to transport fluid.

[Vinyl]

Why I asked about 2nd seal on the pump side - I thought it might be needed since outter part of the valve (these cross alike terminals) is very active in theory I presented above ( lots of fluid is carried through these cross alike terminals) and I figured second ring of seal would be also needed to secure the operation (from pictures 1&2 by mozieau you cannot really tell if there are or not - first picture showing pump side of the valve assembly appears to have no outter orings while second picture showing also pump side of the valve assembly (second assembly) appears to have some outter oring))

[CitroJim]

Ok, I think mystery is solved

You have done some very valuable and excellent work here Vinyl Thank you, your dedicated detective work and need to fully understand is much appreciated and as a result our knowledge of the EPIC pump is now greatly increased

[wesacosa]

Adi, the problem will most likely be the viton o rings under the top solenoid. They can be replaced in situ for next to no money. Have a read through the post, there will be measurements mentioned and a description on how to do it. Only use o rings that can cope with fuels, not garden equipment. If you decide to go a head, make sure everything is very clean before you remove the solenoid and use petroleum jelly to hold the new ones in place during reassembly. Also be aware that the wires that you will see (13 I think) will have very brittle insulation that can fall off exposing bare wires. This will then require a new fasceau soldering in (200 euros for the part) or replacing each wire. Although air ingress can be a problem, if the problem gets worse when warm, it's generally the o rings.

Hi, sorry for the thread revive. I have a heavy leak from the top solenoid on my XM EPIC. I see from search on here they can be done in situ, but I also read elsewhere that on some of the solenoids plungers and springs can fire out when you remove them. Is there anything I can break or drop/lose by taking the top solenoids off in situ. I also see the point about the wiring, but can it be made easier by unplugging anything in the wiring or removing any harness clips etc ? I really don't think I have the skillset to do a full pump seal rebuild so keen not to take it off the car, plus setting the timing afterwards sounds like something that's easy to mess up too
Thanks

[CitroJim]

To be honest, whilst it can be don in-situ I'd never recommend it. Too much risk of many 'ping! f&^k it' moments occurring...

Also, if you have the pump on the bench you can replace all seals and rubbery bits, including the driveshaft oil seal, in one go. You ca be sure if one lot is on the ay out then all will be. It's a nuisance when you do one only to find another leaks a few weeks later...

Also, when working on thee innards of any diesel pump, extreme clinical cleanliness is needed. You generally don't get that in an engine bay, although yours may be the exception

[wesacosa]

To be honest, whilst it can be don in-situ I'd never recommend it. Too much risk of many 'ping! f&^k it' moments occurring...

Also, if you have the pump on the bench you can replace all seals and rubbery bits, including the driveshaft oil seal, in one go. You ca be sure if one lot is on the ay out then all will be. It's a nuisance when you do one only to find another leaks a few weeks later...

Also, when working on thee innards of any diesel pump, extreme clinical cleanliness is needed. You generally don't get that in an engine bay, although yours may be the exception

Thanks Jim. Yes I would agree with that, its just I think a full strip down and rebuild is beyond my capabilities , plus the retiming of the pump looks a nightmare too. I have spent so many hours on this car recommissioning it I just can't face another epic (pun intended!) job