Need to fix an oil leak at the injection pump on a 88'300SDL. Is there a way to keep the pump timed during removal? If not, what is the procedure for setting the pump timing? Thanks in advance for your help.
Beatle Juice...

Hello,

BECAREFUL! Do NOT use a magnet to remove the parts, because that can cause them to twist and alter the timing. Use a pair of pliers or carefully remove the metal peice with your fingers. You might be able to remove the socket, replace the rubber gasket and reinstall it without taking out those peices. I do not know the procedure to adjust the timing, but it should be done by a pro. If you do have problems, the dealer will tow your car to the shop, remove the injection pump and send it off to have it rebuild/retimed, and its not really cheap after u add in towing, labor to remove and reinstall the pump, cost for retiming it, etc.

You really need some special tools for your purposes. To answer your basic question: there is a tool that threads into the side of the injection pump that freezes the pump shaft. The tool might be inexpensive I'll look if anyone is interested.

By freezing the shaft and removing while the engine is at TDC (really doesn't matter where as long as you don't turn it - but TDC has all the marks lined up also) one can reinstall and go (usually).

We use Bosch's high pressure timing method and it requires a major special tool. Once in with basic timing we also use an inductive piezio transducer style standard timing light for overall testing.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Steve,

Please tell me where I can buy the tool.

Thank you in advance.

David

I would recommend repairing the leak with the pump mounted on the engine if this is possible. Leaks often occur on the side cover, feed pump gasket, or on the shut-off lever. Most of these leaks can be repaired on-engine with small hands.

But if you really want to bring down the pump, do this.

1) open the side plug on the governor side.

2) turn the engine clockwise (engine rotation) until timing pointer is centered on the hole of the plug.

3) Engage the tool which Steve recommended. Tool will lock the pump camshaft. Engine crankshaft angle will be at approximately 14 to 16 degrees ATDC.

4) remove all low and high pressure lines and any electronic connection to the injection pump

5) Remove the vacuum pump in front of the pump. Loosen center bolt on pump camshaft clockwise. This is a reverse threaded bolt.

6) Remove flange mounting bolts of injection pump housing on timing chain cover.

7) Pull out the pump.

8) INSTALLATION: do steps 1 to 7 in reverse order.

Word of caution: This job may be difficult for a DIY.

I hope this helps.

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Jake

Here is the special tool number 601-589-05-20-00 and also you need A,B light 617-589-08-21-00 to set your injection pump timing (if you turn the timing gear).

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MB STARS Master Guild Technician,17 years MB tech
14 years independent shop owner

They also wear out on the top of the injector socket as well. There is a small rubber o ring that costs less than a dollar and its best to change those. To find out exactly where its leaking, its best to clean the engine, dry it, and watch carefully. You can also used compressed air and try to locate the leak that way too.