High Pressure Diesel Injector Pump Seal Replacement

[rsmarais]

If the problem only started after you stripped the pump I can only guess that you possibly forgot to fit or fit the small tapered seals incorrectly causing an internal leak.

This is a guess only. Hope it helps

 

[thusi4444]

Hi,
I have changed the seals on my clk 270cdi fuel pump.
Can you please let me which way around the the two plastic pipes fit into the pump
Many thanks

 

[daniemj]

I suppose it will not be possible to remove the center piece out without removing the heads etc? I just want to change the 2 big greenseals on the center drive?

 

[th3h1ghlander]

My 2002 W203 C270 CDI had a leaking high pressure injector/diesel pump . After I had to replace the seals on my high pressure pump a second time I decided to document how I did it to possibly save others from making the same mistakes I made

Pump part numbers:
Bosch part no: 0445 010 019
MB part no: A612 070 00 01

MB seal kit part number :
A000 078 07 80

Required Tools:
T40 torx bit to suite T bar or ratchet.
T30 torx bit to suite t bar or ratchet.
8mm long reach socket or socket with extension.
8mm spanner.
13mm socket.
14mm spanner.
Ratchet with adaptors for torx.
Terminal screwdriver.
Flat screwdriver
Longnose pliers.
Mini circlip pliers.
Bench vice.
Small hammer.
P800 sand paper.
Clean rags.
Washing container with paraffin.

Drive the front wheels onto ramps or raise the front end to gain access to the engine and gearbox covers. Using a 13 and 8mm socket, remove the bash plates/engine protection covers. I recommend doing this as you are bound to drop something into the engine bay while working on the pump.

Open the bonnet and remove the top engine cover to expose the engine and the Injector/ high pressure pump.

Remove the vacuum generator by releasing the vacuum pipe and loosening the two bolts that fasten the vacuum generator. Remove the generator carefully. You now have much better access to remove the pump.

Using a 14mm spanner, loosen the steel pipe located on the right hand side of the pump that feeds the injector rail.

Take the 8mm spanner or socket and remove the clamp holding the plastic supply pipes on the left of the pump.

The pump is fastened to the engine block with three bolts. Take the 8mm socket with extension and loose all three bolts. Remove the pump by wiggling gently. The o-ring seal will make the pump stick a little. Remove the pump in the direction of the vacuum generator taking care not to drop the pump's drive adaptor that is located on the back of the pump. (This photo shows the vacuum pump in the way however you would already have removed it.

Place the pump in a bench vice applying just enough pressure to hold it from moving while you strip it apart.
Use the T40 torx and ratchet to loosen the head bolts. The bolts are extremely tight and I would not attempt loosening it with an L shaped torx. I placed the torx bit on each bolt and gave it one firm tap with the hammer to break the seal before attempting to undo it with the ratchet. The hammer helped for sure

I took note of the position of each head on the pump and kept all parts of the three heads separate from the other. I am sure this would help with reducing wear and it just felt right doing so.

Remove the circlip from the port and carefully remove the three bits from the pump. (Two cylindrical shaped parts and a spring)

Now turn the pump on its face and use the T30 torx to undo the three bolts that holds the pumps main shaft. Use a small flat screwdriver placed in the recess on the casing of the pump. Slowly pry the inner part of the pump away from the casing. Do so little by little
carefully by slowly wedging until there is enough space for another screwdriver on the opposite side then wedge out the inner part of the pump completely.

Wash all the parts with paraffin and place them on a clean surface free of any contaminants.

Change the two o-ring type seals and place the unit on a clean surface ready for re-assembly ( if supplied in your kit).

Remove the line fittings from the pump using a longnose pliers. Protect the fittings with a rag before using the longnose. Not much force is necessary to remove the fitting. Then remove the o-ring and bush from the casing.

With the fittings removed use a terminal screwdriver to wedge out the old seals from the port.

Lightly sand down any corrosion from the casing and head where the seals mate between the two surfaces. I suspect this is where many go wrong leaving the surface as is. Sand both the casing and head surface.
Rinse the casing and head blocks in paraffin.

Fit the main shaft assembly back into the casing and tighten the bolts.

Fit the cylindrical parts/jet/restrictor and spring back with the circlip. Carefull, if the spring drops and bounces its gone!!! You know it!

Install a o-ring into the port followed by the bush and fitting.
Place the bush and o-ring on the other end of the fitting.

Start assembly of the head by installing the steel tapered seal into the recess around the hole. Be sure the seal is the right way around i.e. the inwards taper must be pointing towards the hole. This is another part where I went wrong the first time around because of the seal being so small I did not notice the taper.

Place the ball valve into the gap and hold it firmly as movement may upset the tapered seal and move it out of position. Build the rest of the components onto the head. Fit the small and main black seals into their respective positions.

With the head upside down, insert it upwards into the casing keeping the head bolts handy.( Make sure the eccentric pump contact surface is aligned in the casing hole). Align the head properly with the protruding fitting on the casing and apply pressure to mate the two surfaces together. Use your free hand to fit the head bolts. If at any time pressure was released rather be safe and re-check that all seals are still in position especially the metal ring.

Torque the head bolts down in a cross sequence until they are properly fastened. I applied as much force as my mini ratchet allowed as these need to be really tight.

Repeat the process for all three heads.

Before re-fitting the pump I replaced the plastic clamps for the clear pipe as these are almost guaranteed to be broken. I also replaced the o-rings on the clear pipe fittings.

Reverse the removal procedure to fit the pump.
Enjoy a leak free pump and a cabin that smells of leather instead of diesel!

Just did mine, your instructions were invaluable! The pictures were very handy and gave me the confidence to do the job myself. Thanks!


Sent from my iPhone using Tapatalk

 

[puppetnonsense]

Any chance of these images coming back online? The instructions are great, and the cooresponding images would really help.