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Replacing the injector pump seal insitu

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Second time I've had to do this job, and not too bad to do really. When the injector pump shaft seal fails - fuel leaks into the timing case from behind the injector pump timing belt sprocket. In the case of this vehicle, the fuel contaminated a 2-month old Dayco timing belt to such an extent that it snapped after just a few hundred miles. The method of replacing the seal is the same for all the following :-

2.5 N/A

2.5 TD

200 TDi

Possibly also the 300TDi as it's very similar to the 200TDi.

2.5TD engine owned by Mark Jenkins of this forum.


The tools you see on the top of the cowling are what I use to remove the viscous fan. On this engine the thread is Left hand. The hook tool engages in a hole in the water pump pulley, and the spanner can then undo the nut behind the viscous unit. People have been known to use a hammer and chisel, this is a bad idea, as the shock can damage the viscous unit or even bend the water pump shaft. Once the fan is undone the bottom radiator hose can be disconnected from the water pump and hooked behind the oil cooler pipes.

Also remove the top hose completely. The cowling is only held in place by 5 x spring loaded cross-head screws to the top of the radiator frame. Remove these and the cowling will lift out.

Should look something like this now.


The two fan belts now, first thing is to slacken the 4 x 13mm head bolts on the water pump pully. The belt tension should hold the pully strongly enough to do this.

Slacken the alternator adjuster and push the alternator towards the engine, the belt will then lift off the pulley, but is trapped behind the PAS belt. To release tension on the PAS belt, slacken the three 13mm bolts that hold it to the bracket and then the pump will twist down. The belt will then lift off and then the alternator belt.

Water pump next. undo both jubilee clips that secure the hose that connects the water pump to the thermostat housing. All bolts are M8 and 13mm heads. The three bolts that form a triangle close to the alternator have a habit of seizing, so be careful when undoing them. The bolts are of varying lengths, so make a note of their position.

With the pump and belts removed, it should now look like this:-


Now the dangerous bit - undoing the crank pully bolt. This is not a recommended method, but with care is an easy and very effective way of undoing it. The bolt on this engine is 199lb ft, and the 200 TDi is 251 lb ft.

The head is 41mm, so I use an impact socket that will take the hard shock needed to undo the bolt, plus a breaker bar to lock the bolt. The engine turns clockwise, so if it turns and the crankshaft bolt is held still, then the engine will undo the bolt for you. Make sure the socket is a snug fit and on the head of the bolt as far as it will go, make sure the bar is in such a position as to prevent the socket and thus the bolt from turning. Remove the fuel cut-off switch wire from the back of the injector pump -


This will prevent the engine from starting.

Bar and socket in place on the crankshaft bolt and locked with the breaker bar.


Now rest the bonnet down (in case something flies off), put the key in the ignition, and briefly turn the key for only one second. There should be a sharp bang/snap, and with any luck the starter will have undone the bolt. Open the bonnet and check, the bolt may have moved, but is still tight, so you might have to do the same thing again. Once one or two turn of the bolt have been made by the starter, the bolt can then be unscrewed in the normal way with a ratchet. With the bolt removed the crankshaft pulley will hopefully slide off. Thye are quite often very tight, and a puller may need to be borrowed or made to extract it. This one has only been on a couple of months so it came of easily.

Timing case cover now

This is secured by several bolts aroung it's edge and one in the centre of where the injector pump and camshaft sprockets are. The bolts are of varying lengths, and in order to make sure they go back in the same position as before, a simple cardboard bolt memory can be made, like this one:-


The cover sits on two locating studs so you may have to apply some leverage to get it off. The cover can easily be cracked, so take care.

Once the cover is off, it should now look like this:-


There's immediately a strong smell of diesel, and there's evidence of a small trickle of it from under the pump sprocket and down towards the bottom of the timing case. Mops up with aworkshop wipe, so it's quite a bit.


The timing has now to be set prior to removing the belt. There is a pip on each of the three sprockets, and three arrows cast into the back face of the timing case. When all three pips are aligned with their repective arrows, the timing is set. I've used tippex to highlight the pips.

Crankshaft sorocket:-


Camshaft sprocket on the right, and left is injector pump one.


Now slacken the two nyloc nuts that hold the belt tensioner in place and it'll drop down - releasing tension on the belt, which can then be removed and discarded.

The injector pump sprocket has to now be removed. there are tw threaded holes in the sprocket, these are for a puller if you have one or can make one. Otherwise, use a blunt screwdriver to stop the sprocket from turning and undo the centre nut (19mm). The sprocket is a taper fit and locates on a small woodruff key. Normally a sharp rap with a hammer is enough to free the sprocket.

The offending seal is now visible.


There is a circlip that helps retain the seal:-


Removing the seal is tricky - the metal surrounding it is all alloy, and as the seal is recessed, there is no way of levering it out withough a high probability of causing some permanent damage.

To remove the sel, it has to be pulled out and the following method is best.

Drill a small hol into the seal halfway between the pump shaft and the housing, take great care not to go to far or you may cause internal damage to the pump. The seal is metal at this point and you will feel the drill when it has gone through. carefully screw a long self-tapping screw into the hole - again taking care not to go too far.

Like this:-


Now the seal can be pulled out with a pair of pliers.


As soon as the seal comes out, the diesel inside the pump starts to trickle out, and continues to do so as it sef-syphons fuel out of the filter housing. The new seal just taps in and I used a 27mm deep socket to do this. It's very easy to damage the seal lip, as it tries to reverse itself as the seal is tapped in. I damaged the first one and had to use a second on this job. A very thin screwdriver, such as a watchmakers or small electrical type will help to keep the lip in.

Once in, replace the circlip, put the sprocket back on, again using a blunt screwdriver to lock it while the centre nut is tightened. The injector pump will no longer be in it's timing position, so it will have to be put back when the timing belt is replaced.

New belt, new gaskets, and putting it back together is pretty-much the reverse of what you've just done.

Don't forget to tighten the crank bolt to it's specified torque, it may come undone after a while if you don't, and then you'll need to replace cranskaft and pulley perhaps.

Word of warning - Be VERY careful if you choose to undo the crankshaft bolt by the method described here.

If you are swinging a hammer around, levering with a big ol' screwdriver, or just plain losing your temper, bear in mind a replacement injector pump is several hundred pounds! :o

Les. :)

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