Leaking fuel pump

Martin Beevers · Post by **Martin Beevers** » 01 Feb 2008, 10:53

Hi all,
I have been experimenting with veg oil in my 95 Xantia 1.9 TD for a while now. I did all the research, that appeared to qualify a try at least. Bosch pump etc...
All was going well with 50% then 75% veg no worries. The other week I gave 100% a go and I noticed that the Fuel pump had sprung a leak.
It appears to be coming from a join in the main body of the pump at the front.
Have I blown the seals in my pump?
Will I be able to replace these seals myself or is it a specialist job?

slim123 · Post by **slim123** » 01 Feb 2008, 20:12

I don't think that the veg oil will have caused this as I have been running a couple of cars on veg for a few years now and have had no problems, although I would not use 100% especialy in the winter. I tend to go for 50% veg in the winter and 75% veg the in the warmer months.

Have a clean up and another look, the most common place that I have seen leakage from is the accelerator spindle. What you have to remember is that this style of pump was designed to be used on such things as tractors, where the revs would be set and stay the same for a few hours, when they used the pump on the car the seals around the spindle would sometimes fail as they were not realy designed for constant movement of the accelerator through them.

The spindle seals can be replaced without removing the pump, just the top needs to come off, this may sound easy but it is a bit of a fiddly job and sometimes best left to someone who has done this before.

Regards
Slim.

Post by **CitroJim** » 01 Feb 2008, 21:14

I've seen exactly this problem on a Xantia running veg and dismantled the pump to see the root cause. If not, as Slim says, the throttle spindle, it'll be the body to head gasket (actually a big, shaped O ring) that is leaking.

On the Xantia where the pump failed like this, the fuel return line back to the tank was found to be blocked, resulting in what I believe was excess pressure in the pump leading to a blow. The return line can be blasted with compressed air to clear the blockage but you would be wise to remove the tank unit (under the big bung under the back seat) and check for gunge on the fuel pick-up strainer)

Such a problem will also "blow" the fuel filter body at the white thermostat button eventually.

As Slim says, the replacement of the pump body gasket is quite fiddly and before you do your working one, try to practice on a scrap pump. Another severe difficulty, if you have the coded kepyad type pump, is removing the anti-theft shielding on the pump to actually get to the top cover mounting screws. It can be done by drilling out but it is a real difficult job.

I can give guidance if necessary.

Again, if you have a coded keypad pump, getting another pump from a scrapper and replacing it is not really an option unless you can also grab the keypad and know the code. You can swap over the electronic module that controls the stop solenoid from one pump to another but that involves removing TWO shields...

Failing that, it is possible to replace a coded pump with a non-coded pump if you are content to loose the keypad facility. All you then need to do is pick up an ignition-switched supply to operate the stop solenoid.

KP · Post by KP » 01 Feb 2008, 21:58

I had this once on an old xantia myself, a mk1 M reg and was on 100% then but never had a problem on my old N reg xantia and now my V plate.

As said above checking all the filters and lines for blockages is the first port of call then repairing the pump

Martin Beevers · Post by **Martin Beevers** » 05 Feb 2008, 18:41

Cheers fella's,
I had a look the other day, and it does appear to be coming from the accelerator spindle.
Jim, will this repair be covered in a haynes manual?

Post by **CitroJim** » 05 Feb 2008, 18:59

Martin Beevers wrote:Jim, will this repair be covered in a haynes manual?

Not at all Martin

They don't really tell you properly how to remove the pump from the engine and that's not easy either

As I said earlier, the repair is easy enough and can just be done without pump removal if you have the earlier fully mechanical pump without the keypad and stop solenoid shielding. The latter are a dockyard job and a half and a major undertaking just to remove the shielding. I can always do a photo-sequence if it would be helpful?

Let me know the type of pump you have and we'll take it from there.. 95 is a bit of a cross-over year and it may have either. Do you have a black pot with three wires coming out of it above the throttle spindle and a Lift Sensor on No.3 injector? If so, you have the semi-electronic pump.

I have a spare fully-mechanical pump here, known good, if you just want to swap the pump complete. Unfortunately I don't have a good semi-electronic pump, only a very leaky one that needs new seals. If the mechanical one I have is of any use to you, let me know and we'll see what we can do..

XantiaMan · Post by **XantiaMan** » 06 Feb 2008, 18:15

My car has just started losing oil (defo veg on the floor), its not massive amounts, and its only since i started running 100%, maybe the extra pressure of running a thicker oil especially when cold has caused it, car still runs perfect so i will leave it for now and run a bit on unleaded to keep then oil thin and reduce further damage, thats assuming it is the pump thats weeping as i cannot think of anything else in that area that would cause a leak!

Post by **CitroJim** » 06 Feb 2008, 19:06

XantiaMan583 wrote:My car has just started losing oil (defo veg on the floor),

Gareth,

Check your return line back to the tank is clear. Slip it off and blow down it and if all is OK you should be able to make the fuel bubble in the tank

If a bit blocked, a quick blast from an air-line works wonders. Failing that, a bicycle pump...

You're right though, the thicker veg, especially when cold, will up the pressure and search out weak spots.

Can you see from whereabouts on the pump it's leaking from?

XantiaMan · Post by **XantiaMan** » 06 Feb 2008, 20:11

citrojim wrote:
XantiaMan583 wrote:My car has just started losing oil (defo veg on the floor),
Gareth,

Check your return line back to the tank is clear. Slip it off and blow down it and if all is OK you should be able to make the fuel bubble in the tank

If a bit blocked, a quick blast from an air-line works wonders. Failing that, a bicycle pump...

You're right though, the thicker veg, especially when cold, will up the pressure and search out weak spots.

Can you see from whereabouts on the pump it's leaking from?

Hi Jim,

I had a look tonight and the pump is clean from the front but i see sign of veg down the back/block of the engine, its not dripping only weeping at this stage but enough to cause a drip onto the undertray and then on the floor. This is of course with the engine hot and it may be when its cold that oil is forced out of a weak seal.

I've noticed since running 100% so i'm going to cut back on it, put £30 quids worth of diesel in it tonight so its about 60% veg now, and see if the weeping reduces, get the engine cleaned aswell.

Is it known for the pump to leak at the back? Whilst it wont be serious, its still a problem and i want it to stop!

The return should be fine i did the pick up a few months ago, but may check again soon.

Gareth

Post by **CitroJim** » 06 Feb 2008, 23:11

The usual places for a leak Gareth, are from the throttle spindle, the main head to body joint, the stop solenoid and more rarely, the cold start shaft (on the back side of the pump) and the timing device covers, those oval plates on both sides low on the body of the pump, toward the middle. The common factor is that all these are sealed with O rings and my personal jury is still out on whether or not some veg oils attack these rings.

I'm soon to do a photo strip of one of these pumps and whilst I'm doing it. I'll conduct some experiments on the O rings.

The big difficulty is seeing where exactly the leaks come from due to the anti-theft shielding effectivly hiding so much of the pump.

I'd not worry too much if it's just a tiny seep as they can seep for ages without getting much worse (after all, most Lucas pumps do after a few years!). You need worry only when it reaches Torrey Canyon proportions but do keep a close eye on it.

EDIT: Check the fuel inlet and return banjo unions are not weeping and confusing the issue. I't just could be a weepy leak-off pipe where it joins the return pipe at the tee-piece.

XantiaMan · Post by **XantiaMan** » 07 Feb 2008, 07:26

citrojim wrote:The usual places for a leak Gareth, are from the throttle spindle, the main head to body joint, the stop solenoid and more rarely, the cold start shaft (on the back side of the pump) and the timing device covers, those oval plates on both sides low on the body of the pump, toward the middle. The common factor is that all these are sealed with O rings and my personal jury is still out on whether or not some veg oils attack these rings.

I'm soon to do a photo strip of one of these pumps and whilst I'm doing it. I'll conduct some experiments on the O rings.

The big difficulty is seeing where exactly the leaks come from due to the anti-theft shielding effectivly hiding so much of the pump.

I'd not worry too much if it's just a tiny seep as they can seep for ages without getting much worse (after all, most Lucas pumps do after a few years!). You need worry only when it reaches Torrey Canyon proportions but do keep a close eye on it.

EDIT: Check the fuel inlet and return banjo unions are not weeping and confusing the issue. I't just could be a weepy leak-off pipe where it joins the return pipe at the tee-piece.

Thanks for the advice Jim.

I'm also not convinced that 100% SVO is a good thing for a pump designed to run dino, whilst many wont get problems there will be a few that will notice the signs. The hunting from a cold start because the fuel is too thick to get to the injectors and atomiste properly must cause excess pressure to build up until its warm enough to flow.

Even with the engine hot yesterday, i took a sample of oil/fuel from the filter housing and it was no-where near the temperature of the coolant although i've not removed the thermostat from it.

Working it out, its false economy to run 100% if it causes problems like this, even at a 50/50 mix on a typical 60 litre fill, your saving at least £15 by running veg and at 50/50, it runs identical to diesel!

I'm going to run it like this for a little while, i think its been weeping for a good few weeks anyway but today got quite bad, enough to see the tell tale signs of oil spotting on the tailgate.

Will see what it looks like today!

Gareth

XantiaMan · Post by **XantiaMan** » 07 Feb 2008, 09:14

Bad news is its the pump, and its leaking at the back -

Its leaking from the small plate at the bottom as per picture.

If anyone can help me PM me, as i need the car for work and i'm about for fork out £400 quid to get it sorted!

Post by **CitroJim** » 07 Feb 2008, 09:53

Gareth,

Do you mean the oval'ish plate at the bottom in the middle held with the two screws?

If so, this is one of the timing device covers and there is an O ring behind..

It's easy to replace but the pump needs to come off to get at it.

£400? is that from a Diesel Specialist or a Citroen dealer? A Diesel Injection Specialist may work out more economical to fix this.

MikeT · Post by **MikeT** » 07 Feb 2008, 12:55

Gareth, as Jim states, that oval plate gives access to the timing components. It's a low(ish) pressure area (as opposed to the higher pressure provided to the injectors).

Just thought I'd add my own experience regarding SVO use and a fuel pump leak. (I think I may have the same leak as Gareth, it drips from the underside of the pump but where it originates from is out of view. A Bosch engineer took a cursory glance and couldn't see where it was coming from either).

Last spring I noticed this leak (after running on a mix of 5 litres of unleaded with half a tank of SVO) but after being quoted £££'s for a pump repair/rebuild I decided the car wasn't worth the expense and left it. To this day, I don't know where it's leaking from but it certainly hasn't got any worse. Nor have any other fuel leaks materialised. I think this is a pertinent point because I've since covered 8000 miles fuelled by 90-100% SVO. (Incidentally, I don't mix it with unleaded any more, I use either diesel or paraffin or 100% SVO, depending on ambient temperature).

I am beginning to suspect that SVO does not attack the fuel system or the pump seals chemically; but the added stress of pumping higher viscosity fuel has probably been the final straw for one 9-year old seal within my pump.

Interestingly, I did read one article that suggested the service life of these seals is appx 10 years.

XantiaMan · Post by **XantiaMan** » 07 Feb 2008, 15:06

It was roughly 400 quid for remove, fix seals pressure test and refit.

I've driven the car 80 miles today, after 20 miles it was still leaking from the timing cover, another 10 miles and it had stopped!

However

i now started to spring a leak near the fuel return banjo as evidenced by the oil on the intercooler pipe.

There is a rubber pipe/cover with a small hole in the end, removing this oiled dripped out? I'm thinking this is part of the problem aswell, i'm not sure what this bit of rubber covers up, maybe a pressure relief?

It still runs great and a little dribble out of that cover is livable although i would like to cure it, likewise the banjo join,is it just a case of nipping it up or replacing the copper washers?

Maybe a coincidence but i added a splash of acetone yesterday and it did not talk long for the leak to get worse very quickly, it was only 1.5ml to 1 litre!

Thanks all

Gareth