[How to replace the throttle spindle seal on a Tdi Injection pump]

This method is applicable to 200 and 300Tdi pumps and is also suitable for most Bosch NA and Turbo pumps fitted to Citroen/Peugeot diesel engines. The right up here was done on a 1995 300Tdi Defender, without EGR valve.

Before you start it is vital that the outside of the pump is spotlessly clean, so get that jet wash out. Pic below shows the problem, leaks of diesel from throttle shaft.

The Bosch part number of the pump is on the opposite face to the red arrow. Its etched in but will be covered in dirt so clean up with a scouring pad. On a 300Tdi Disco/Defender no EGR, its 0460 414 098. 200Tdis will be different but it will start 0460.

Once cleaned up, mark position of throttle lever and spindle. There is a groove cut across the end of the spindle. Also mark position of groove relative to body of pump. Remove from shaft by undoing nut marked with green arrow. Remove return spring and plastic spacers. DO NOT undo any other nuts on the lever. Remove split pin from pin holding throttle cable. Remove throttle cable from bracket by squeezing adjuster nut.

To get at the 4 allen bolts that need to be removed to take the cover off, the max speed screw (dark blue arrow)and idle screw need to be turned forward towards the radiator. The max power screw also needs to be removed - light blue arrow.

Before you touch these, mark their position with paint or use vernier calipers and mark the protusion of each screw. On a 300Tdi remove the tamperproof covers over the lock nuts. On a 200Tdi, remove the lockwire and lead seals. Then remove the maxpower screw entirely, wind the idle stop and max speed stop screws forward to clear the rear allen bolts. A screw driver through the throttle cable bracket can be used to screw forward the max speed screw. Also remove the fuel return and boost connections - yellow arrows.

Remove the four allen bolts holding on the top cover, be prepared for a diesel spillage.

Gently push the throttle spindle through the cover as you remove the cover.

You should now be looking at this...

The max power screw presses against the lever with the purple arrow, the screw has to be removed or the cover wont go back on. The end of the throttle spindle is marked A. To remove it from the lever marked with an orange arrow, gently rotate the whole mechanism 90 degrees and it will disengage. The cylinder with the gear teeth is the centrifugal governer. VERY carefully cover the pump with a clean plastic bag. Make sure no dirt falls in otherwise the pump will be ruined or you will block an injector.

This is what the shaft and the brass bush looked like on mine, no wonder it leaked!

The bush can be knocked out with a suitable drift, I gently warmed the cover first before knocking it through. Do not attempt to dismantle the shaft further.

I got the replacement parts from Panda Fuel Injection at Wallington, Fareham, Hants. I took the cover and shaft in. They will need the Bosch part number of the injection pump. They replaced the bush - new one is steel, supplied a new shaft and transferred the springs over and also supplied a new gasket for the top cover. Total price £20, done whilst i waited - top marks to them!

So for the refit.

Engage new shaft assembly with lever in injector pump by turning through 90 degrees. Make sure small spring and spacer is as in picture of the inside of the pump.

Crank of spindle must be as shown when you feed it through top cover. If its incorrectly positioned it will jam.

Cover should drop down with a slight bit of resistance as o ring goes through. If it stops tight - DO NOT force, lift off and try again.

Once down, refit allen bolts.

Refit fuel return and boost banjos.

Refit max power screw with protrusion EXACTLY as before dismantling. Return idle stop and max speed screws to original postion.

Refit throttle return spring to body of pump. By finger, turn throttle spindle so that alignment slot is as the original one. It should neither be at the most clockwise or anticlockwise extremeties. You should get 1/6 to 1/8 of a turn on it.

With a pair of small pliers, carefully pull throttle spring anticlockwise, engage loop on throttle lever and then fit lever to spindle. Ensure lever/spindle and spindle/body marks align. Ensure stop on lever is hard up against idle screw. Refit spindle nut, refit throttle cable.

Make sure electrical connection to stop solenoid is removed. Crank engine on starter until oil warning light goes out.

Refit stop solenoid connection.

CAUTION: Start engine but be prepared to immediately kill ignition if once engine fires it starts to rev up and runs away.

If all is correct engine will fire and idle.

If it fires but then immediately dies you have got the throttle spindle too far clockwise when you refitted the levers.

If engine runs away, spindle is too far anticlockwise. Adjust and try again.

DO NOT CHANGE SETTINGS OF MAX POWER, IDLE OR MAX SPEED SCREWS.

If you cannot get a normal idle you have refitted somrthing incorrectly.

Can the moderators link to tech forum please?

Brilliant write up, my Discovery had exactly this problem of the throttle spindle seal leaking, without instructions would have been totally lost. Took the throttle spindle housing into my local Bosch dealer Diesco of Ipswich and they were extremely helpful and had all the parts in stock, they did show a little surprise that I had taken it to bits and said they didn’t recommend it, they also gave me the impression that they did not think I would be able to get it running properly again. Any way glad to report that following instructions to the letter it started straight away after priming it with the cut of wire detached and it runs a dream with no diesel leaks and no need of any further adjustments, just to make sure of the measurements of the adjusting screws before I dismantled not only did I measure them with venire gauge but backed this up by taking close up photos of them which enabled me to count the number of threads protruding. The part numbers I was supplied were Spindle bush 1460324333 spindle O ring 1460210008 Throttle cover gasket 1461015302 all purchased for the sum of £10.14. Thanks so much for taking the time to write such a good article.