W202 C250 fitting clear fuel pipes - help please?

[jools182]

Car has been struggling to start for a while, only just got around to buying the hoses as I'm out of work and struggling a bit

I was given 5 flexible pipes and 2 o rings by Mercedes Stockport, but I am not sure this is all I should have

I have replaced the 2 pipes which are easiest to get to, as shown on this photo

As far as I can see there are still 4 others to replace, 3 of which seem fairly visible, but when looking around underneath I noticed another one which I think has been missed from my replacement parts. I have outlined the one I think is missing from my parts in green on this pic, the other one outlined in red I think I already have.

These are the pipes I haven't yet fitted

I have a load of questions about this job, I hope someone can help

1. Am I missing a flexi hose from my replacement parts?
2. I have no idea where the 2 o rings supplied by MB are supposed to be fitted, can anyone tell me where they go on the photos?
3. The flexi hose that has a banjo at the end, am I supposed to have replacement washer or anything when I fit the new one
4. Do I need to take off the manifold off to access all these pipes


I really have no clue so I don't mind if you go into minute detail

It took me about half and hour to work out how the little clip things work on the 2 pipes I fitted!

Thanks in advance for any advice

 

[JonathanC250]

Hi there, i have just done this to my car not too long ago, you require 6 clear pipes and i would think the o rings they have supplied would be for the fuel prefilter.

And yes to get access to the clear pipes you will need to remove the inlet manifold, make sure you get the 10 seals to replace the old ones

The part numbers for the 6 hoses are
605 070 12 32,
10 32
15 32
07 32
08 32
14 32

and the inlet manifold seals are 604 141 01 60 x 10

might be worth you getting the two black fuel hoses that feed the filter and return to the tank, while you have the manifiold off
202 470 09 75
10 75

and replace the o ring on the stop solonoid, black box on side of fuel pump
this is where mine was leaking from in the end!

021 997 75 48

hope this helps, good luck!

Jonathan

 

[jools182]

thanks for the help

one of the o rings I already have is 021 997 75 48

the other o ring they have given me is 601 997 01 48, not sure where this one goes

 

[jools182]

can anyone tell me where the pre filter is?

 

[spock500]

can anyone tell me where the pre filter is?

The pre filter is next to the main filter held in with a 10mm bolt

If your short of cash best thing to do is replace the O rings only, not the whole pipe -

There's a forum member 'SilverSaloon' who sells the whole kit, very reasonable too - I have just ordered a set for my 300TD

 

[jools182]

Thanks for that, I've already bought all the pipes though

So this is the prefilter?

Also, one other question, where is the stop solonoid?

cheers

 

[spock500]

Thanks for that, I've already bought all the pipes though

So this is the prefilter?

Also, one other question, where is the stop solonoid?

cheers

Yup, that's the pre filter, stop solenoid is on the side of the injection pump almost directly under the second pipe around from the pre filter if that makes sense.

It will become clearer once you have the manifold off as its pretty dark with it on.

 

[jools182]

Help please guys!

is this the stop solenoid?

and is it just held on by one bolt?

 

[Bluebee]

I have this same problem I only just bought this car before christmas and had nothing but trouble after running low on diesel I topped it up with diesel and parked up went to college came out and wouldn't start My mate managed to start her but really struggled to start afterwards then it did it just after christmas took it back to where i got it from thy sorted it out but its doing the same am I best replacing all the pipes and o-rings how much is this likely to cost ? and will it deffo solve this problem

 

[SilverSaloon]

am I best replacing all the pipes and o-rings how much is this likely to cost ? and will it deffo solve this problem

if you want the cheapest fix, you could replace the orings and see how that goes. or you could spend £80ish + labour and replace all the possible issues. i'd try just replacing the easy stuff (ie the seals) 1st

 

[artz]

Jools - Great thread and thanks for all your help. I just wanted to add my warnings from the perspective of a complete novice/fool.

OK - my experience with new fuel pipe o rings, (save money?), new pipes (x 6, inc irritating banjo joint with copper washers = not supplied by MD) then after manifold off too many times too mention - a new (----ing) stop solenoid?

Symptoms of problem = won't start if parked up hill = air in fuel pipes = start of nightmare!
What a car etc etc....... but typical car manufacturer trick which gets us all... why would you make a vacuumed fuel system with multiple places/seals for possible air ingress... because you want to sell lots 'o' parts to divvies like me???

Stage 1 = Replace all easily available o ring seals (ebay £13.99) = useless!
Stage 2 = Take off manifold and do the rest, put everything back = useless again!
Stage 3 = Replace all pipes, manifold off again etc, (no change from £60) = useless once again! - getting angry but accept fate as already know I was a fool taking this on as a complete novice!
Stage 4 = Read MB club forum/thread and remove stop solenoid and replace o ring but... and this is the rub, while taking off the pipes from beneath the stop solenoid I have managed to break off part of the small housing that the nearest pipe fits into = total nightmare complete - new part is... stopped listening after £150 something plus something called VAT.
Do I feel a twit or what?
Anyway lessons learned are as follows: Number 1. You get a few problems when starting up hill = carefully remove stop solenoid and replace £1 o ring befre anything else. Quite probably most cars will need this at around 100k to 120k and maybe even all the o rings (including manifold x 10) replaced but definitely not until you have replaced stop solenoid o ring first (5 min job with 30mm hex/star piece/socket - begrudgingly got 1 from Halfords for £3.99)!
Number 2. Be bloomin careful, especially if you're a novice/mug like me!
Number 3. Love repairing my own car even if I am a fool!
Number 4. Love forums like these they're so optimistic
What a car etc. etc...
p.s. - please post if you need any further novice info or just to take the pi-- even?
p.p.s I'm going for discs and pads next???

 

[johnsco]

One more little problem when removing the 2 screws that secure the diesel shut-off solenoid ...
They can be very tight.
The wretched torx (star) driver tends to slip out of the heads, and it is easy to damage the heads.
Damn !!!!!

 

[artz]

C250TD - air in fuel lines

HooHar

Success at last & without new fuel shut off valve!

Just needed one more o ring under the pre-filter which was clearly yet another massive mistake to add to my litany of foolishness! -(I did replace o ring on hose which goes into pre-filter but not the larger one under the plastic fitting, No 29 on diagram below)
So for any other novices out there with C250TD's which won't/has trouble starting when parked up a hill and/or you've got air in the clear fuel pipes.

Thanks to Jools182 for pic

Step 1. Check the Achilles heel first - replace the o ring under the pre-filter which is held in by 1x10mm bolt, you might as well replace o ring on pipe fitting too, then try it out for a few days before moving on.
Part numbers for these o rings & pipes on this thread
*You have obviously checked all your pipes & will replace if leaking/damaged etc..
Step 2. step 1 didn't make any difference so good idea to have an o ring day and buy 10 manifold o rings (because it is worth taking it off now) plus all associated o rings found on the diagram below omitting any already replaced. You should only have spent about £25 - £30 so far

Pay special attention to the fuel shut off valve and probably best/easiest to remove it using (x 2 bolts)= 30mm hex/star drive to fit your ratchet - Halfords do them for less than a fiver - they can be really difficult to get off. Please be careful when pulling off the pipes though. I broke mine trying to lever the pipe off without looking or taking shut off valve off. (diy repaired)
**Personally I would not bother with the Banjo fitting/pipe even though I did replace the pipe and little green o ring I think it may have been surplus to requirements so I would leave that until the very last... if not make sure you get the two copper washers and little green o ring when/if buying the pipe. (always make sure to replace o ring on the other end of pipe though)
You may of course just want to fit all pipes (£60 ish) rather than save your cash with just fitting o rings but the choice is yours!
Finally, try and fill all pipes, shut off valve, main filter & pre-filter with diesel and put everything back together, there's also an opportunity here to give your manifold and pipes a good clean but I didn't bother. (fool!)
So hopefully this might help others not to make all the irritating (foolish) mistakes I made! - and massive thanks to everyone on this forum, couldn't have done it without you!

What a car etc. etc.

 

[WillF]

Hi

I'm just going through this same problem with my newly acquired 238,000 mile 2.5TD which came with a largely unused Viton kit.
Is O-ring 29 secured by the pegs sticking out from the base of the pre-filter?

 

[Dieselman]

Hi

I'm just going through this same problem with my newly acquired 238,000 mile 2.5TD which came with a largely unused Viton kit.
Is O-ring 29 secured by the pegs sticking out from the base of the pre-filter?

No. It fits round the top collar.

 

[frstep]

Hi
I'm just going through this same problem with my newly acquired 238,000 mile 2.5TD which came with a largely unused Viton kit.
Is O-ring 29 secured by the pegs sticking out from the base of the pre-filter?

Will,

I hope this problem is solved quickly... and that the car then give you the reliability that it gave me!

F.

 

[WillF]

Thanks. Glad I asked about O-ring 29 as if I'd put on the base of the filter it would have cut the fuel off completely:-

I've not found the problem yet but have changed the pre-filter, filter and all the O-rings including the one on the back of the stop solenoid. This was easier than anticipated; I removed the manifold support bracket but not the manifold itself. Taking out the two tubes allows the solenoid to swing away exposing the o-ring.

Now to try a set of new tubes...

 

[WillF]

So I fitted a complete set of tubes today and put it all back together but there was still diesel dripping off the bottom of the stop solenoid.

Revisited the o-ring on the back of the solenoid and found I'd damaged it on fitting. Replaced it, all seemed OK at first but it's not...

I'll check the o-ring on the back of the stop solenoid again but should I be thinking now about a new stop solenoid unit?

Also, should there be an o-ring as well as the two copper washers on the banjo bolt that's on the end of one of the 6 tubes? I think it goes into the pump.

Anyway it was nice visiting Mercedes Bristol. I don't get Customer Service in the French car dealerships I normally frequent.

 

[WillF]

After re-reading all the relevant info on the forum I revisited the stop solenoid o-ring to find the one I'd fitted was mangled. So fitted a slightly smaller one and so far so good, no bubbles!

 

[johnsco]

Don't neglect the most obvious places where air can get in.
My E300TD has not been running as sweetly recently as it should.
Changed the main fuel filter last night (Routine change ... Nothing special).
Noticed that the centre sealing washer of the old fuel filter was in very poor condition ... God knows why !! All it has done for a year is sit there. And it was me who fitted it.

Fitted new filter.
Car fired up - No problems.
Then - Surprise Surprise.

This morning the car goes like a rocket .. Far better than it's run for some time.
I can only conclude that there was an air leak on the fuel filter seals - Especially the centre one that was in such poor condition.

The fuel filter seals have such a big area to seal ... And they can leak like anything else.