Thread: Injector Return Pipe: Clip Removal and Orings Part/Sizes (Tips)

Ive recently had to do this a few times, in situations where I could not afford to drop and loose one of the clips so id like to share my simple method.

The first time I did this was while replacing the inlet manifold seals, a the time I just did the seals, but in hindsight I should have done the return line orings and oil/fuel cooler valley seals , as by the time the manifold seal is leaking these other seals will be in a similar condition, (as same material and age) and ready to start leaking, and if you are replacing the inlet seals you are half way there to the valley seals.

And if you choose to put the injector shields back on (I did initially, but wont again) these will prevent you being able to monitor either the injectors or return pipe for leaks.

Symptoms I had that was due to leaking Oring on 2 injectors were: Intermittent Rough Idle / Engine Rocking at idle, And when cold starting, it would fire and run for a few seconds then stall, and not start again, it would only start after bleeding some fuel (and air) from the Schrader (tyre) valve on top the engine. It seems as the fuel drained out the leaks overnight, air replaced it and made its way up higher and blocked the system.

Now the orings for Tdv8 3.6 (Tdv6 2.7 too) are LR part number LR019118 , genuine ones are like $6 from overseas plus shipping each, (which adds up with V8) so I figured id look into alternatives as its just an oring, I looked hard to find the sizes but only found one mention Buy Rubber ring 374891 3.5*6.5*1.5 (A50016/A50016,LR019118, LR 019118,06.56939-0051,06.56939-0134) 0.16 € which states NBR rubber 3.5 x 6.5 x 1.5 which i think means 1.5mm CS (cross section) (thickness) and 3.5mm ID (inside diameter) and 6.5mm outer diameter so i ordered a pack of FKM rubber (thinking to get longest lasting, but this means harder and difference in fitting) ones but they didnt fit.

My neighbour is a mechanic and he had a generic ORing (no mention of material) set and I took the closest one out of that, 6mm x 1.5mm and it fit very easy and didnt leak.

I ordered a set myself off ebay (1200 for $25) that stated NBR (I think all black ones are this) and had a few different 1.5mm CS sizes to try.

I tried 7, 6.5 and 6, and only the 6 fit widely, a couple fit the 6.5, but i just did them all 6 for ocd reasons and that they hadnt been leaking.

The clips too can be bought separately, ill have to find the part number. But you should get some spares in case you loose any.

My process for removal is:
(ideally remove the underguards first, as other wise if you drop something, you might not get them off easily without the car running, warning if the car is in raised position and you reconnect the battery it will lower to normal height, also consider getting a magnetic pickup tool and telescopic inspection mirror)

Use a very small flat head screw driver to get in under the "bridge" section of the clip (this is the bit between the 2 legs) and gently pry and rotate the screwdriver to slide the clip out just enough

To use a pointed nose pliers to grip the exposed leg section and then pull the clip the rest of the way out and then out it down somewhere safe away from the car.

To refit the clip, use the pliers to grip the leg in the same place used to take it out, using fingers rotate the clip so that it will orientate correctly with the 2 holes when located near the injector

Slide the clips legs into both holes and you should be able to get the clip in about half way with just the pliers, then or otherwise you can press it in from behind with finger or screw driver while holding in place with pliers.

Clip should go in easily, otherwise you may not have the return pipe pressed in far enough.

Odd that a German brand is using std metric and not their DIN 3771 sizing.

Looking at the orings, Id suggest they may be 2.8 x 1.8mm cross section (I havent had one to check)