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1981 240D
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185 Posts
Discussion Starter #1
Okay, here is another problem. A few weeks ago, I posted a thread requesting help with fuel hoses. I asked for the correct sizes of the rigid plastic hoses that connect to banjo fittings on the main filter assembly and the fuel injection pump. That same week I went to safeflite to have my windshield replaced. They of course refilled my windshield washer fluid reservoir (I have always left it empty since the pump grommet leaks). The next day when I came home, there was a puddle under the front of my car, which I dismissed as windshield washer fluid. After several days I noticed the puddle was not evaporating and my driveway area smelled like diesel (more than usual). I touched the puddle and it was in fact diesel.

I got on a creeper and went under the car. It seems there was quite a leak coming from the bottom of the hand-primer assembly. In an effort to stop the leak, I replaced all of the rigid pastic hoses with rubber 1/4" inside diameter fuel injection hose. I also replaced the copper crush washer on the fitting in front of the hand pump. I replaced the original old-style hand pump with a new hand pump. I sprayed everything off with brake cleaner. Now, I do not see any diesel residue on the engine, but there is a "puddle" of diesel smaller than a dime under the engine compartment. It is driving me CRAZY that I cannot find the leak. It seems like it is leaking at about a drop a day. It is not that am worried about a major leak related cotastrophe, but it is the principle of it. I don't like having leaks. Anyone have any ideas?
 

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2013 MINI Copper S Clubman, '84 300CD-weekend car
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10,152 Posts
Closely inspect all fuel lines, sorry, that's all I can come with.
 

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1984 300D
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5,070 Posts
Clean and degreas the possible areas you think could leak. Take the car for a drive. Park it and let things cool off.
Starting from the highest point and working your way down; slowly run you Fingers over the parts and frequently check your fingers for Diesel Fuel.

Do you know if your Fuel Injectin Pump is an MW Pump (the Delivery Valve Holders can be removed with a regular socket) or an M type Pump (the Delivery Valve Holders need a special splined Socket to remove them).
The M Fuel Injection Pump has a Copper Crush washer and an O-ring to seal it. The O-rings can go bad on them. And they will seep Fuel right where the Delivery Valve Holders screw into the Fuel Injection Pump.

The MW Fuel Injection Pump does not have the O-rings.

Another issue can be that the metal seal rings that go under the Banjos on the Fuel Injection Pump as the come from the Factory are Aluminum. Sometimes the Aluminum ones cannot be reused and are better replaced with Copper.
 

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Registered
1981 240D
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185 Posts
Discussion Starter #4
Clean and degreas the possible areas you think could leak. Take the car for a drive. Park it and let things cool off.
Starting from the highest point and working your way down; slowly run you Fingers over the parts and frequently check your fingers for Diesel Fuel.

Do you know if your Fuel Injectin Pump is an MW Pump (the Delivery Valve Holders can be removed with a regular socket) or an M type Pump (the Delivery Valve Holders need a special splined Socket to remove them).
The M Fuel Injection Pump has a Copper Crush washer and an O-ring to seal it. The O-rings can go bad on them. And they will seep Fuel right where the Delivery Valve Holders screw into the Fuel Injection Pump.

The MW Fuel Injection Pump does not have the O-rings.

Another issue can be that the metal seal rings that go under the Banjos on the Fuel Injection Pump as the come from the Factory are Aluminum. Sometimes the Aluminum ones cannot be reused and are better replaced with Copper.
It must be an MW type because none of the fittings require a splined socket. When I removed the banjos I did not see any sort of washer. I posted a question in another thread (one you commented on) where I originally created the thread to ask about the sizes of the different return and overflow hoses. The question was whether or not the banjos required a washer. I went and bought a box of assorted copper crush washers in case they did. I didn't have a chance this weekend to get under my car to inspect components, but my "puddle" seems to be drying up. Once I get her back on the ground I will driver her around the block to get things moving again.
 
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