fuel leak by pump - PeachParts Mercedes-Benz Forum

allenying · #1 08-08-2017, 02:17 AM

hey ya'll, my car stalled out, i changed the fuel filter, it was pretty dirty, i pumped the primer before starting, and then it's running again. but, there's a fuel leak from or just below that primer pump. it only leaks while the engine is running...
1) what's the next step???
2) do you always change the larger screw on filter every time you change the little clear plastic one?
3) should i be worried about why the fuel filter got so much gunk in it? i'm nog running bio anymore, just regular petro diesel.

thaaanks.

Maxbumpo · #2 08-08-2017, 01:04 PM

Quote:

Originally Posted by allenying

hey ya'll, my car stalled out, i changed the fuel filter, it was pretty dirty, i pumped the primer before starting, and then it's running again. but, there's a fuel leak from or just below that primer pump. it only leaks while the engine is running...
1) what's the next step???

Buy a new primer pump and replace it. New pump should come with a new copper washer.

Quote:

Originally Posted by allenying

2) do you always change the larger screw on filter every time you change the little clear plastic one?

No, but no harm in doing so.

Quote:

Originally Posted by allenying

3) should i be worried about why the fuel filter got so much gunk in it? i'm nog running bio anymore, just regular petro diesel.

How long was that filter in use? Did you change it after you switched back to #2 ULSD, or is this the first change?

Diesel911 · #3 08-08-2017, 03:44 PM

Be sure to remove the old copper crush washer if you remove the old hand primer.

Note that there is Fuel Supply/Lift Pump rebuild kits that have all of the copper crush washers and new valves for the inside. The generic versions used to be about $17 and that included the shipping cost. The real Bosch kits are in the $25-$30 range.

BillGrissom · #4 08-08-2017, 09:32 PM

Yo dude, why tell us what car u got? If older white plastic primer pump, replace it. Cheap, many posts.

allenying · #5 08-08-2017, 10:42 PM

hey,
i thought the car was in my signature, it's a 1985 300D turbo diesel sedan, w123,

by new bosch kit, you mean new bosch primer pump?

i've been back on the petro diesel for a few months now, and hadn't changed the filters after stopping bio i went thru the switching filters after starting bio, but didn't realize it was expected to need change again after, especially considering people blend all sorts of ratios of bio to petro.

if it's not necessary to change the screw on filter, i don't like to do what's not necessary, or just doesn't hurt to do.

i'll look into changing the primer pump, it looks hard to reach, but do you just need to unscrew it from above?

thanks!

allenying · #6 08-08-2017, 10:48 PM

pelican parts has the
genuine mercedes $31.25
bosch $15.50
febi bilstein brand $9.50

since you guys defaulted to mentioning the bosch, is that better than the genuine mercedes part?

ROLLGUY · #7 08-08-2017, 11:29 PM

Quote:

Originally Posted by allenying

pelican parts has the
genuine mercedes $31.25
bosch $15.50
febi bilstein brand $9.50

since you guys defaulted to mentioning the bosch, is that better than the genuine mercedes part?

I would go with the Bosch. The old style primer pump can be removed with a vise grip type pliers, and the new pump takes a 17mm. A crows foot works best, as there is not much room to swing the shortest of wrenches.

Diesel911 · #8 08-09-2017, 01:45 PM

The problem with the old style hand primers is that the body is made of thin soft Aluminum. When you get a wrench on the flats and start to turn they most often deform and strip around the flats.

Due to the close quarters some people use a Basin Wrench (plumbing). You or one of your neighbors may already have one.

The also make a Basin Wrench head that goes on socket extensions.

Be sure to get the correct new type hand primer because the look similar but have different threaded ends.

BillGrissom · #9 08-10-2017, 02:21 AM

Sorry, I was/am viewing on a phone, where page doesn't show signature.

allenying · #10 08-17-2017, 05:40 PM

it seems the leak has stopped now, maybe it was just backed up due to the clogged filter.

thanks