Hi all,
I discovered fuel leaks on my injection pump at the delivery valves and ordered a 32 point female socket to replace the faulty o-rings. I have a handle on that one but there is another leak source. It is a 3 second drip from what appears to be a faulty gasket on a canister attached to the bottom right of the fuel pump assembly. It is just to the left of the engine mount strut that is bolted to the engine block with four 13 mm head bolts and the lower end of the strut rests on the motor mount. I can see the drip coming out of the bottom of the can with the help of a mirror. The can is attached to the aluminum billet housing and has a ring holding it with three thorax screws. Can anyone chime in as to where I can find any information to fix it? One outboard screw is accessible, the second inboard screw just barely, and the top third one not accessible. I don't know what the can does and hoping the gasket can be replaced without missing any adjustment up. It looks as it the pump has to be removed to get to it. I dred removing the pump and causing a new problem when putting the pump back right. Is removing the injection pump difficult? I have considerable mechanical experience with Mercedes and other cars, but not too familiar with injection pumps. Any leads appreciated,
Ted

Does it look like #661 or #662 in this diagram?

'Called a "Fuel Thermostat" [It's an Engine Coolant to Fuel, heat transfer device]

Uses a "C" clip (part #679)(Need c-clip pliers or teensie tiny needle-nose)
to secure part # 676... the O-ring(part#673 ) is behind #676.

Attached Thumbnails

 

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'84 300SD sold
124.128

No,
It’s not connected to the injection pump with a hose. If you look at the picture of the injection pump, it’s an oval can that is a lower part of the fuel injector assembly. It’s the second joint from right to left that is bolted on to the main housing. Lower right portion looking at the pump a joint about 3 inches from right to left.
I was at a dealer Saturday and without seeing the pump he said they had to send similar leaking pump situations to a Bosh pump rebuilder to "reseal" the pump for $1,000.00.

For that much money I have to at least pull the pump to eye ball it. Do you know of any good articles to remove the pump and reinstall it?
I started it up and confirmed a steady 2 second drip.
Ted

Ted, in the first post it sure sounds like you're describing the fuel thermostat. Some are attached to the block ahead of the engine mount arm, some are attached to the arm itself. For the type that sits on the engine mount arm, usually it leaks from a worn o-ring (item 673) but the plastic nipple (item 676) can crack. Those parts are avialable individually from Phil or the dealer. I'm not familiar with the type that's attached ahead of the arm.

You can give youself some time by bypassing the fuel thermostat. Run the fuel line directly from the small filter to the lift pump on the side of the injection pump. Shouldn't be a problem this time of year in the northern hemisphere. Don't forget to leave some slack in the fuel line for engine movement.

Resealing the injection pump will cure engine oil leaks, not fuel leaks, if you've already addressed the delivery valves. The lift pump can leak but only through the hoses... unless the lift pump body is cracked.

Removing the injection pump is not terribly difficult but it's a rather involved process to set timing. If the injection pump has not been moved in a long time, expect any movement, removal or even just setting timing, to damage the o-ring between the injection pump and the block. A telltale of a worn o-ring is an engine oil leak between the block and AC compressor dripping to the ground ahead of the engine mount arm.

Sixto
87 300D

thanks for the pic--I need to get the # 700 hoses replaced on mine and didn't know where to look.Thanks again!

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1990 300D 2.5
1991 F350 7.3 Dually IDI

1997 F350 gasser dump
1980 H-D 93 inch Shovel
2000 SE Roadglide

Thank You,

sixto.

I lost track of this one until now.

__________________
'84 300SD sold
124.128