Lucas Delphi DPC Fuel Injector Pump Leak

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Lucas Delphi DPC Fuel Injector Pump Leak

Post by Joris1 »

Hi All,
I have a loved Peugeot 205 1.7 Diesel MkII from 1995 and after sucking in some air through a leak in the fuel filter housing developed a small drip on the fuel injector pump.

Does anyone know if I can just unscrew this bolt on the bottom of the injector pump from where I see the drip coming and replace the seal on it, and would that work ?

It only leaks when cold, and the drip stops after running the engine a few minutes until it warms up.

The workshop repair manual seems to suggest it locks in the hydraulic head and needs to be tightened in a certain order, so not sure if I can just unscrew it and replace the copper ring or O-ring, anybody has any experience with this ?

The pump is a Lucas Delphi DPC pump.
thank you, would really like to keep this car on the road, it has been so reliable for the past 15 years I have it!

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Re: Lucas Delphi DPC Fuel Injector Pump Leak

Post by clydeowenp »

I saw your last post but didn't reply as I couldn't find my DPC workshop manual.
If its a small leak it may evaporate when hot so not be so obvious.
Many years ago I worked for Lucas CAV in Gillingham. My job was calibrating injection pumps which involved rectification including a certain amount of dismantling and changing parts. I didn't actually work on DPC pumps but the features and working principals of all the Lucas rotary pumps is similar.
I managed to get a copy of the official DPC workshop manual, only available to Lucas service personnel working in the field.
Firstly I totally agree with what Jim said, to use his words you need to "clean the outside of the pump to within an inch of it's life". The two things guaranteed to wreck a pump is dirt or water getting inside. I also agree you should wear nitrile gloves, especially if you have sensitive skin or suffer from dermatitis If you have to remove them to do one of the more fiddly jobs wash your hands immediately. We used a specially developed oil to test and calibrate pumps Couldn't use diesel because of health and safety issues (fumes and dermatitis).
One more thing I must add is don't under any circumstances feel around the joint between the pump and the pipe or the pipe and the injector with your finger. If there is a leak it could inject diesel through the skin and into the blood stream. If you must wipe the joint clean with the engine running use a thick wad of cloth. If untreated this can lead to gangrene and amputation. It's even more dangerous to do this on an Hdi, the pressure in the rail is the same as the pressure in a water jet machine, which uses water pressure to cut through metal!
I can provide diagrams and torque settings for most operations but many need specialist tools, equipment and knowledge.
I was going to ask two questions, is this a DPC pump and are you sure of exactly where it's leaking, but you've answered both. This bolt is called the head locating, bolt I often had to change the bolt or the seal on test and never slackened the other other fittings first. You should be alright just changing the seal / washer but be careful not to cross thread the bolt when refitting and also tighten to the correct torque. If you can't get to the bolt with a torque wrench note how tight the bolt is when you undo it and try to tighten it to the same tightness, as near as possible. This isn't ideal but you should get away with it, you may need to remove the pump to torque the bolt.
Your workshop manual should tell you how to remove and refit the pump, you may or may not have to remove the timing belt. On my BX it was possible to remove the pump and leave the sprocket in position, held in place by the two pulley locking bolts.
I've included some diagrams that may be helpful, the one marked Plate 1 shows the bolt you describe (180) and the washer (179) These are also listed in the key to the diagram and the torque value sheet (180 Hex headed screw). Be careful as the centre column is marked lbf in which is not the same as lbf ft which most torque wrenches are marked in. Suggest you use Nm or kgf m. There's also a diagram showing Fig 40 which shows the excess fuel valve (1) and low advance valve (3) and instructions on the order the three components should be tightened. Head fixing screw (your screw) is shown on Fig 37 No.2 and is the last to be tightened. I would recommend you leave 1 & 3 well alone, if you disturb them you may cause another leak. Your bolt is the last to be tightened so you shouldn't need to touch the others.
Should be a fairly simple job, if you can get to the bolt to torque it and if you can get the washer / seal. I don't know if this is a copper washer or a dowty washer (a metal washer with a rubber seal bonded inside it). If you can't get the seal / washer I have a few copper washers and dowty washers . Send me the size and if I have one send me a stamped self addressed envelope and I'll post it to you. Dowty washers are available on Amazon & Ebay but make sure they are resistant to diesel.
Many years ago, when City diesel was first introduced, our engineers warned us not to use it in older diesels including my 1984 BX I had at the time. City diesel or bio diesel attacks the rubber seals on older pumps and causes leaks. New diesels use a different compound that's diesel resistant. Can't remember when they changed. My BX started leaking from the driveshaft oil seal the day I tried to sell it, a real pain!
Hope you find this helpful and not too confusing, let me know if I can be of further help.

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Re: Lucas Delphi DPC Fuel Injector Pump Leak

Post by CitroJim »

Joris, welcome to the forum and Clyde, a most excellent post above :D

Clyde, you are right that the pump can be removed without disturbing the timing or cambelt but just for a basic reseal there is no need to :)

If the pump does need to be removed a small puller (easily made) will be needed to remove the drive shaft from the pump sprocket.

I'd be minded to think the leak is not from the bolt in the picture but just where it ends up as a drip... So often the leak is from the top cover and gravity takes it to the bolt head as the lowest place to form a neat drip...

In any case, don't remove this bolt as it secures the timing ring inside the pump and it's removal may cause issues...

This tread from earlier may help a little and contains a guide I wrote many years ago on resealing the lid and throttle/snow running shafts in-situ...


Hope that helps a little Joris...