W124 Diesel estate fuel lines

[John Turner]

I have been replacing my fuel shut off valve and plastic fuel lines on a 1995/6 w124 300 diesel OM 606 engine. The fuel shut off valve has been leaking, and although fitting new o rings reduced the problem for a few weeks, the leak is still there. This causes difficult starting. I am replacing the fuel lines because they have never been done, and could cause air leaks.

Most of the job was relatively easy, but I am struggling with line 119 (injection pump to fuel filter) in top diagram http://www.detali.ru/cat/oem_mb2.as...GM=717.433&CT=M&cat=19T&SID=07&SGR=120&SGN=04. I assume that I could gain access to the injection pump banjo fitting by removing the inlet manifold (no. 29 here http://www.detali.ru/cat/oem_mb2.as...GM=717.433&CT=M&cat=19T&SID=14&SGR=030&SGN=02), however despite removing bolts 47 and 56, the manifold will not move. Is anything else holding it? Is their a technique, or am I just being too careful?

I would also like to replace the hose from No. 1 nozzle holder to fuel return line (part 146) in first diagram above, but again, not sure how how much of the cylinder head cover must be removed (and what has to come off first) (part 77 in http://www.detali.ru/cat/oem_mb2.as...GM=717.433&CT=M&cat=19T&SID=01&SGR=075&SGN=08). If anyone has done either of these jobs, then any advice would be gratefully received.

If anyone wants part nos. & current prices for this job, then I can provide them!

Regards
John

 

[television]

Cant answer all of it but with the inlet manifold, a few taps with a soft face hammer should release it, they do stick

 

[Number_Cruncher]

To release the crossover pipe, loosen the mixer body (the part with the throttle valve in it on the driver's side of the engine). The crossover pipe is held by rubber O rings at each end.

 

[simon_wall69]

Inlet manifold does need a very good tug, there are only the two torx bolts to remove, you can sort of lever it off on the air filter side by pulling on what it joins on to. I also seem to recall unplugging something but can't remember what.

You will need to replace the fuel shut off valve, and they are ridiculously expensive (about £60 I think.) With the manifold off you should be able to get at everything.

 

[John Turner]

Thanks all for your help. The crossover manifold came away OK in the end - it needed the coupling on the left hand side (when facing engine) prizing with a nylon hammer and screw driver, and similarly to push it back in on reassembly (a difficult job).

I was able to fit a new hose #119 from above, with great care and many small turns of a 17mm spanner/ring spanner (I could not get a socket in there) on the banjo fitting and slid carefully between injection pipes. This banjo fitting bolt is actually a hollow valve and costs over £40 to replace (I did not - but mine claened up well)! Washers either side of the banjo fitting stay in place with nylon o ring (which you must remember to order).

I am sure that the correct way to do this job is to remove the throttle linkages and intake manifold, but that is a major task, beyond my competence and tools. As has been mentioned elsewhere, fuel line #107 from fuel filter to injection pump now arrives with a banjo bolt fitting instead of the clamp it replaces, but the port on the injection pump is threaded and takes the hollow bolt #113 (this time only £3.45), but you need two washers #116. I have not fitted breather hose #146 from no 1. nozzle to fuel return line, since hose seems in good condition.

Parts overall were:

#32: 605 070 14 32 line from thermostat to pre filter £4.85
# 119: 606 070 05 32 return line from injection pump to fuel filter £7.65
#65: 606 070 02 32 line from pre filter to feed pump £5.45
#86: 606 070 00 32 line from feed pump to fuel filter £4.20
# 107: 601 070 53 32 line from fuel filter to injection pump £4.95
# 113: 601 990 08 63 hollow screw for line 107 £3.45
#116: 007603 012113 seal ring for line 107 x 2 £0.48
#126: 0179972248 seal ring fuel line overflow valve on injection pump (I failed to order this part, but old one was good- really should replace)
#128 007603 012102 seal ring x 2 fuel line and overflow vlave on injection pump for line #119 £0.48
#29: 601 997 01 48 seal ring on prefilter £0.58
# 23: 601 070 05 46 shut off valve £55.50
#8: 601 090 15 52 fuel filter plus seal rings x2 £9.85
#146: 605 078 05 81 breather hose from nozzle no 1 holder to fuel return line £8.40 (not yet fitted because needs removal of throttle linkages and engine cover.

Replacing the leaking fuel shut off valve seems to have given the engine back its power. It is satisfying to see the fuel running through clean lines and not to see any air bubbles.
Care is needed when fitting new lines because they come with plastic horseshoe clips that push in to secure the fitting, which seem very weak compared to the sturdy metal clips on the original lines.

Overall a staisfying job, which took about 2 hours.

Thanks for advice and help along the way.
Regards
John

 

[John Martin]

Hello John,
I have the same problem with my 300D saloon, I have noted all the parts you listed and will order them soon..

I wonder If you know where its posssible to get a parts list either in book or CD form?, had a search but unable to get anything for the UK, would like the up to date mercedes numbers etc, my local dealer is not customer friendly especially on the older cars.. Thanks if you, ar anyone can advise..
John Martin

 

[SilverSaloon]

you can subscribe to the official online EPC on the merc website, or better still join the offical MB club and you get access free.