E300d Fuel Leak Block Help

[swa65]

Have replaced my 95 E300D fuel filter as there was a leak. Started fine but was still leaking from the stop valve on the top of the housing. Came to start her up yesterday and wouldn't have any of it. Looks like there is a air blockage in the fuel line, coming into the housing on the right. Any idea's?

 

[Parrot of Doom]

Are the fuel lines dark yellow/orange?

Sounds like one or more of your fuel lines need replacing. Common problem with age, totally DIY-able with practically no tools. Its not expensive as things go, £10 per line or thereabouts.

Also check the prefilter (to the left of the main filter) o-ring - it doesn't come with the new pre-filter, you have to order it separately.

As a temporary measure you may be able to get by by parking your car nose down on a slope.

I suggest you search the forum, its been covered many times over.

 

[swa65]

Thanks for that. Yes the lines are as you have said. Tried looking for info on forum. What do I need to search for? Bit difficult to park the car nose down when it wont start.

 

[Parrot of Doom]

Look for "fuel leak" - include the inverted commas. You have the OM606 engine, its a very common fault, I've had to do it on mine.

Basically, charge the battery up full as you'll be cranking it a lot once done.

Replace each line individually so you don't get them mixed up. Buy all of them from the dealer.

To remove the lines push the white horseshoe clip in. The lines might take a bit of elbow grease to pull out, they get stiff with age, a flat blade screwdriver is useful as a lever but be careful. To put the new ones on, horseshoe clips in, put line in hole, then pull horseshoe clip out to lock. Some of the lines only have a clip at one end, a metal plate on top of the fuel filter holds the other end in. You'll have to remove that plate, just a small spanner for that, dead easy.

Don't let any debris or dirt fall into any lines or sockets.

Fuel pre filter (to the left of the main filter) comes off with a little bolt, pulls upward (screwdriver can help work it loose). You want the o-ring that sits on the top of it, go to the dealer for one.

Also check you've put the o-ring on the main filter correctly, theres only one.

You can get good access to the fuel lines by removing the windscreen washer bottle, just a couple of bolts and 2 electrical plugs IIRC.

A small mirror is very handy for looking at the two connections under the fuel shutoff valve (small black cylinder on side of injector pump, has 3 fuel line connections).

Starting can be helped by filling the main filter with fresh diesel. If you don't have a fuel container, you can use diesel injector cleaner instead from the nearest garage.

Once everything is back in place, turn the engine over for 10 seconds, then let it rest for 10, then turn over again, then rest, etc. You'll see loads of air bubbles in the new lines, eventually the engine will catch and she should be fine from thereon.

 

[Bolide]

IMHO the lines don't need replacing but the O-rings do. The O-rings are about 80p each from Mercedes

I have had to replace a shutoff valve before now as it was leaking. If a new O-ring on this doesn't cure the problem I'd replace it

Nick Froome
www.w124.co.uk

 

[Parrot of Doom]

Didn't know you could get them from Mercedes now, but if you can thats great.

 

[swa65]

Thanks guys,

Thats a real help. Am off to Mercman in Southampton to get a replacement valve and then the O rings from Mercedes. Keep my fingers crossed thats all thats up.

 

[BlackC55]

Try not to get a second hand one. How do you know its ok?

I have some "o" rings in my collection if you want any. I can do you a good price on some.

 

[swa65]

A big thanks to BlackC55 for the advice and the O rings. Really great to find someone so helpful and generous and a Merc specialist. Christmas came early. Well I managed to fit all the new O rings, which were really flat and brittle. All fitted apart from one. The plastic end broke, on pushing it back into the housing. A few expletives where muttered. Mercedes in winchester didn't have one, so I am picking up one from Merc Portsmouth this morning. Fingers crossed that will do the job. Will keep you informed. Once again thanks BlackC55.

 

[Bolide]

Mercedes dealers can get virtually all parts on a next-day basis if it's in the UK. If stock is only in Germany it takes a couple of days

It's worth getting to know the parts guys as they're generally knowledgeable and helpful. It's worth asking who is the expert on your car - normally there's one person who knows W124s

Nick Froome
www.w124.co.uk

 

[BlackC55]

A big thanks to BlackC55 for the advice and the O rings. Really great to find someone so helpful and generous and a Merc specialist. Christmas came early. Well I managed to fit all the new O rings, which were really flat and brittle. All fitted apart from one. The plastic end broke, on pushing it back into the housing. A few expletives where muttered. Mercedes in winchester didn't have one, so I am picking up one from Merc Portsmouth this morning. Fingers crossed that will do the job. Will keep you informed. Once again thanks BlackC55.

Anytime.

 

[swa65]

All on and started fine after a few goes of course. No air block anymore but still got a leak from the shutoff valve, as Mercman didn't have one. Really find £48 + vat a bit steep from mercedes. Yes Mercedes in Winchester said it would take two days to get me the part so thats why Portsmouth. If anyone has a shutoff valve sitting on there shelf I could find it a real good home.

 

[swa65]

Well thought I had it sorted. But yet again she is not starting. Can't see any bubbles in any of the lines was running fine last night started fine several times yesterday. Is it just this shutoff valve that is causing the problems?

 

[swa65]

If there's a will there's a way.

Took the shutoff valve off, and noticed that when screwed fully out there is a split pin running through the shaft that looked like it was stopping one screwing the valve all the way out. So I drilled and tapped it out and yes the valve screwed all the way out to reveal a very brittle small O ring. Broke the second I tried to remove it. Was going to go searching in Winchester to see if I could get a replacement O ring. But had to use the car to pick up some furniture. So got some Red Gastite and generously covered where the O ring should sit and carefully screwed the valve back into the fuel filter bolt. Didn't put a split pin back, just in case it was still leaking. Put all back in the car and she fired up fist time. No leak and runs fine. Will try and find a O ring and fit the split pin. But for a quick fix and a saving of £48 + vat fell pretty chuffed.

 

[Parrot of Doom]

The dealers sell the o-ring, its a common item they may well have them in stock. Pence.

 

[swa65]

Refitted with new o-ring and split pin from Halfords. Total cost £1.39. I did talk to Merc parts in Winchester and they said they just sell the whole unit. No separate o-ring listed.