Fuel Pump Leaking - Replacing Oring 6 x Seals Tour

[Abbas]

The leak kept driping from the electric connections so disassembled whole pump and ended up replacing all 6 seals ... more pictures are added for upper part of pump
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Hello Group.
A few days ago I had a leaking fuel pump and it turned to be a weak Oring seal which I replaced and along the way I replaced all 3 seals and took some pictures to share with the group.

The following 4 pictures are for the fuel pump, the serial number,  hanging on the brackets and with various connections.

Download Attachment: Fuel Pump.JPG
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Download Attachment: fp_serial.JPG
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Download Attachment: fp_bracket.JPG
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Download Attachment: fp_connections.JPG
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This pictures show the the filter in the intake from fuel tank.
Download Attachment: fp_filter.JPG
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This picture shows the bottom part taken out and the brushes that build-up the pressure in the pump. Also appearing the first Oring seal. Download Attachment: fp_brushes.JPG
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This picture shows the middle inner part with two seals apprearing - the large one and the smaller one. Download Attachment: fp_middle_part_two_seal.JPG
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The 3 parts beside each other and the brush on the side.
Download Attachment: fp_3_parts.JPG
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Download Attachment: fp_brush_rubber.JPG
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Here are the pictures of the upper part of the pump with the other 3 seals - 2x at electric connections and one big one 57x2mm to seal the upper part that holds the magnets and coil. Of course had to unsolder the small springs to take the connection out and put in the small seals at electric terminals - as Hans mentions.

Download Attachment: upper-assembly.JPG
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Download Attachment: upper-coil.JPG
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Download Attachment: 3-seals-upper.JPG
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Download Attachment: Internal-view-springs.JPG
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[mbzse]

quote:Originally posted by Abbas

Hello Group.
A few days ago I had a leaking fuel pump and it turned to be a weak Oring seal which I replaced and along the way I replaced all 3 seals .../...

Abbas and List,
Great pictures showing pump parts! Please note, in all there are six seals for this electric fuel feed pump.
Some info about this can be read in message:
http://sl113.org/forums/index.php?topic=3746

Quote ""For the 280SL electric fuel pump (small model) a rebuild kit is available. Kit has new brushes and three of the six needed O-rings. Small O-ring mounted inside of pump (8,5x13x2) is missing as well as the seal rings at the electrical connections (red and brown plastic parts). BTW, these O-rings should be a square cross section. To disconnect the electrical connections, these must be soldered off.
The large 71x2mm O-ring seal between upper and lower pump body halves is not in the kit either.
Repair kit No is A 000 586 0147. The large, 70mm dia O-ring for the flat lid at the bottom has part No A 010 997 5045 and is furnished with the kit. The separate order No for the pair of brushes is A 000 548 0442""


/Hans in Sweden

[ja17]

Hello Abbas,

Thanks for all the good photos and information.  I am sure a lot of listers will be glad to see exactly where that intake screen is located.

Joe Alexander
Blacklick, Ohio

[George Des]

As one of the other posters pointed out, there is an additional o-ring seal between the "can" and the upperpump body that should also be checked out for possible leakage. Once the "can" is removed you will also have access to the motor brushes and can not only assess their condition but also the condition of the commutator which on pumps with a long service period may be worn down considerably. The brushes should always be checked out as a matter of course to ensure they are serviceable if you've gone through the trouble of removing the pump and disassembling as far as the pictures show. The armatures can be rewound with a new comm if it is too far gone. You'll know by the depth of the ridge that the brushes have cut into it. A rewound armature w/new comm will run about $80.00 or so. The brushes in the MB repair kits are difficult to replace if they do not have a shunt wire relief cut to allow easy passage through the brush holders. You can modify these with some careful filing work or by ordering brushes w/the relief cut in them. Ensure the "can" is replaced exactly the way it was otherwise the pump will run in reverse.

George Des

[Abbas]

Thanks all for words of encouragement. I always wanted to contribute to this wonderful group. I do not know if other car model owners are blessed as us the Pagoda owners to have such a dynamic and professional space to share ideas and experiences from all over the world.

Note that I only had leaks in the lower and middle parts of the pump - so I did not want to fix the other parts unless they were broken - following the old saying ...
 
[eventually I ended up replacing all because the leak was comming from the electric connection].

I took the pump to a shop that is specialized in fixing Bosch Diesel fuel injection systems. I was afraid to let my mechanic handel the pump and open it.

I bought the Orings from a local shop in Dubai that is specialized in selling seals - I brought over the seals and he did the measurements.

When I checked the Internet the 3 Orings would have cost me about 40 Euros (15 for the Orings and 25 for shipping)

280SL W113 1969 Ivory
E280 W124 1995 Silver

[George Des]

Abbas,

The brushes look to be in good shape, so you can leave those as is. As I pointed out in my other post, these can be a pain to replace unless that relief cut is in the top portion of the replacement brushes--the fit in the holder is just too tigh to allow passage of the brushes and shunt wire w/o it. When replacing these terminal o-rings I usually coat them with a very small amount of "Seal All"--a fuel resistant sealer to ensure they will not leak again. This is cheap insurance against having to go back in there again. Before putting back on the car,I would recommend building a small test fixture with an old can and some fuel hose to make sure that the pump is spinning in the proper direction with no leaks.

George Des