I have a fuel leak that is dripping off the bottom of the support bracket on the end of the injection pump just to the right of the bolt head. I have loosened the 4 pipe unions and put a 14 mm spanner on the stubs behind but they are all tight. Also I put a spanner on the timing hole plug and that is tight! I cannot see exactly where the leak is originating from but it seems to be at the very end of the injection pump and possibly dribbling down between the end of the pump and the bracket bolted on the end.All the injection pipes and the leak off pipes are dry and I am confident they are not leaking.
Short of removing the bracket to get a better look ,which I am reluctant to do as we are away in the van at the moment has anyone got any suggestions as to where it may be leaking from? Is it likely the pump body is cracked?How are those stubs sealed into the end of the injector pump?
Thanks in anticipation.
My image is upside down i am afraid !
That is the turbo oil feed pipe at the edge of the image( to help you understand the image!) 9
I has same issue and it turned out to the pump body gasket itself so had to go for a rebuild.
Worth checking it's not coming from the under lda arm, you can get replacement seal for that for a couple of quid and it's a 5 min job.
Possibly the head seal O ring. Common leak on Bosch pumps. Not a difficult job ( with pump off engine tho) . Had to replace one on a friends 300 tdi Discovery.
Number 29 in diagram. ( diagram just for illustration only, most Bosch pumps are similar) .
1984 Caravelle 1.9 DG 34 DAT
2008 Audi TT 2.0 Tdi 170 Quattro
2010 Audi A4 Avant 2.0 Tdi
I had watched that video but I have had a closer look with the help of a mirror and I think the leak is actually from the 3 sided “bung ?” In the end of the pump. So now i need to figure out if that can simply be taken out and it’s seal or washer replaced , but I am thinking that the 3 sided nut is trying to warn me not to !
Completed our holiday in Derbyshire with frequent checks to see that the leak was not getting any worse.
Once home i made a card pattern of the 3 sided “nut” and used a dremmel with a grindstone to modify a 15/16 inch socket. Having done a fair bit of Googling i was happy it was ok to remove the head plug so first of all i cleaned the area with fuel and a paintbrush then i removed the timing access plug thinking it would avoid suction when removing the main plug.Undone the 3 sided plug ,cleaned the plug and the area where the plug goes in, put the new o ring on the plug and smeared it with oil,i used a viton one! ( 30 mm inside diameter x 2.5 mm) and refitted the plug followed by the timing access plug. Bled the air out by slackening the injector pipes and cranking the engine and now i am glad to say the leak is fixed.
Last edited by Cecil on 01 Oct 2023, 06:55, edited 13 times in total.
video gives you an idea on how to go about it.
you can get a seal kit with the long bolt included.
My issue was not the head seal but while I was Googling I found a warning that mechanical pumps as apposed to electrically controlled contain 2 extra small springs that would be displaced if the in situ method was attempted !
Nice work, so your leak was from the where you fit the dial indicator to set the timing? I thought when you mentioned three sided nut it was the triangle looking nut on the side of the pump.
I wasn't brave enough to start disassembling my pump
Bryce wrote: ↑30 Sep 2023, 20:30
Nice work, so your leak was from the where you fit the dial indicator to set the timing? I thought when you mentioned three sided nut it was the triangle looking nut on the side of the pump.
I wasn't brave enough to start disassembling my pump
It was the o ring for the large 3 sided “nut” located on the end of the pump between the outlet pipes , luckily an easy fix .
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