Hi,
I've recently acquired the responsibility for repairing a L plate 306.
This is the boring of the boring but runs and drives fine. It has developed a leak from the fuel pump from the back distributor end. I've owned several Bosch Turbo 306s and have had the engines out and in pieces, rebuilt two into one rat etc.
Does anyone have any advice not involving acetalyne, likely leak point or at an extremely slim chance may have one of these units still knocking about or Bosch non turbo set (did they do them?).
Cheers in advance.
Dog306
Lucas Non turbo pump for XUD9
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mickthemaverick
- Moderating Team
- Posts: 20092
- Joined: 11 May 2019, 17:56
- x 7769
Re: Lucas Non turbo pump for XUD9
For clarity can you post a picture of the one you are after? 
I used to be indecisive, now I'm not so sure!
I used to ride on two wheels, but now I need all four!
I used to ride on two wheels, but now I need all four!
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CitroJim
- A very naughty boy
- Posts: 54541
- Joined: 30 Apr 2005, 23:33
- x 8045
Re: Lucas Non turbo pump for XUD9
Although the leak may appear from the distributor it's much more likely to be from the top lid or the drive side oil seal. Diesel leaks from the lid, runs down the body of the pump and drips from the lowest point.
The top lid seals on a Lucas pump are easy to replace - they consist of a shaped O ring for the lid and O rings for the throttle and cold-start shafts.
A search of this forum will find more details on how to do this job.
There is no need to remove the pump from the engine to replace the lid seals. Just be clinically clean whilst doing the job as any debris entering the pump is likely to damage it.
Be aware that occasionally, the throttle shaft drilling in the lid will have worn oval and a replacement lid will be needed.
A Bosch pump could be substituted but you will require the pump, delivery pipes and injectors as they are very different.
You would also need to do some wiring changes to the stop solenoid and possibly some modifications to the cold-start advance and throttle actuation mechanisms.
You'd be much better off fixing the pump you have. They are good pumps and offer both good performance and economy.
The top lid seals on a Lucas pump are easy to replace - they consist of a shaped O ring for the lid and O rings for the throttle and cold-start shafts.
A search of this forum will find more details on how to do this job.
There is no need to remove the pump from the engine to replace the lid seals. Just be clinically clean whilst doing the job as any debris entering the pump is likely to damage it.
Be aware that occasionally, the throttle shaft drilling in the lid will have worn oval and a replacement lid will be needed.
A Bosch pump could be substituted but you will require the pump, delivery pipes and injectors as they are very different.
You would also need to do some wiring changes to the stop solenoid and possibly some modifications to the cold-start advance and throttle actuation mechanisms.
You'd be much better off fixing the pump you have. They are good pumps and offer both good performance and economy.
Jim
A bit of a Citroen AX fan...
A bit of a Citroen AX fan...
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Gsbx1220
- Posts: 42
- Joined: 17 Oct 2016, 22:26
- x 3
Re: Lucas Non turbo pump for XUD9
Hello,
I am in a similar situation to yourself. I am looking after a 309 with XUD7 Turbo for my nephew. This is now added to the BX & GS which already keep me gainfully employed!
I have a tiny tiny leak from the stop lever shaft. But I have some mild and intermittent running issues on mine, but not sure if it is connected. I started post here yesterday.
You can buy kits from https://injectionpumps.co.uk/product/co ... out-turbo/
I have already done so, but bought the one for the Turbo.
Cheers,
Richard
I am in a similar situation to yourself. I am looking after a 309 with XUD7 Turbo for my nephew. This is now added to the BX & GS which already keep me gainfully employed!
I have a tiny tiny leak from the stop lever shaft. But I have some mild and intermittent running issues on mine, but not sure if it is connected. I started post here yesterday.
You can buy kits from https://injectionpumps.co.uk/product/co ... out-turbo/
I have already done so, but bought the one for the Turbo.
Cheers,
Richard
Richard
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Dog306
- Posts: 3
- Joined: 13 Mar 2026, 15:17
Re: Lucas Non turbo pump for XUD9
Hi, I'm back with Pump pictures. Armed with a brake cleaner like fluid and a paint brush there's a bit of damp under the pin which cranks off off the main throttle control. The lid seems clean.
Having chased leaks round commercial engines for years I understand about travelling and pooling. I also know the value of experience and I'm grateful for all the assistance and suggestions that people have taken the time to write.
This 'back' control (blue arm in pics) is some sort of compensator? I'll give it a more thorough clean and test. Is it a likely leak point?
Thanks again,
Alex.
Having chased leaks round commercial engines for years I understand about travelling and pooling. I also know the value of experience and I'm grateful for all the assistance and suggestions that people have taken the time to write.
This 'back' control (blue arm in pics) is some sort of compensator? I'll give it a more thorough clean and test. Is it a likely leak point?
Thanks again,
Alex.
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CitroJim
- A very naughty boy
- Posts: 54541
- Joined: 30 Apr 2005, 23:33
- x 8045
Re: Lucas Non turbo pump for XUD9
Hi Alex,
The lid does look clean - almost as if it's been changed recently...
The big solenoid on the front face is also a timing device. This, the blanking plug under the round yellow cap and indeed the shaft at the other end of the 'blue arm' can potentially leak...
Only thing to do is to give the pump a very thorough clean and watch carefully...
Somewhere - deep in my archive - I may still have some exploded diagrams of the earlier version of this pump that may help should you need to
dismantle it. Let me know.
The lid does look clean - almost as if it's been changed recently...
It's been many years since I've been inside a Lucas pump but I believe the blue arm, is part of the timing mechanism.Dog306 wrote: 14 Mar 2026, 13:20 This 'back' control (blue arm in pics) is some sort of compensator? I'll give it a more thorough clean and test. Is it a likely leak point?
The big solenoid on the front face is also a timing device. This, the blanking plug under the round yellow cap and indeed the shaft at the other end of the 'blue arm' can potentially leak...
Only thing to do is to give the pump a very thorough clean and watch carefully...
Somewhere - deep in my archive - I may still have some exploded diagrams of the earlier version of this pump that may help should you need to
dismantle it. Let me know.
Jim
A bit of a Citroen AX fan...
A bit of a Citroen AX fan...
-
Dog306
- Posts: 3
- Joined: 13 Mar 2026, 15:17
Re: Lucas Non turbo pump for XUD9
Hi,
I've got another picture, having busy on other stuff for a bit.
It appears to be the joint between the steel, distribution side and the main pump. The fuel is in the recessed joint but not on either side and it doesn't seem to be the cap on the injector pipe side. Can this seal be done in situ? Is it worth trying?
I've got another picture, having busy on other stuff for a bit.
It appears to be the joint between the steel, distribution side and the main pump. The fuel is in the recessed joint but not on either side and it doesn't seem to be the cap on the injector pipe side. Can this seal be done in situ? Is it worth trying?