Leaking diesel oil from spin-on filter - PeachParts Mercedes-Benz Forum

jkoebel · #1 09-29-2007, 02:01 PM

I changed out my fuel filters yesterday, no major crap-ups, but today I notice it's leaking diesel oil from around the seal...

Let's list things I could have forgotten.

I tightened down the big bolt on top until I couldn't move it anymore, I had covered the O-Ring with oil before I tightened it back up...there was a really small o-ring included in the replacement set (fuel filter + a tiny o-ring) that I didn't replace because I didn't know what it went to, could that have caused it? Also the bolt you turn to bleed air, is tightened down until it won't go anymore either.

Maybe it's just not tight enough? Or does it have to line up a certain way? I noticed the bolt has a fluid channel in it for stuff to flow through.

TheDon · #2 09-29-2007, 02:06 PM

don't tighten it too much or you might create stress cracks in the metal

When I did mine I annealed the copper washer and sanded both sides down and then applied some RTV sealant on it since someone nicked the mating surface causing a leak

diesel oil? or diesel fuel? oil is oil and would expect that to come from the oil filter housing if it was leaking not the fuel filter housing

jkoebel · #3 09-29-2007, 02:14 PM

Quote:

Originally Posted by TheDon

don't tighten it too much or you might create stress cracks in the metal

When I did mine I annealed the copper washer and sanded both sides down and then applied some RTV sealant on it since someone nicked the mating surface causing a leak

diesel oil? or diesel fuel? oil is oil and would expect that to come from the oil filter housing if it was leaking not the fuel filter housing

diesel fuel

someone on another forum told me it was "more correct" to call it diesel oil, since it's technically a lubricant, so I did that.

Which copper washer? I didn't take any washers off, but I didn't notice one either. Nothing fell out either, its possible I just didn't see it.

TheDon · #4 09-29-2007, 02:24 PM

its fuel... fuel oil is for furnaces.. same thing

when you removed the spin on did you take the big banjo bolt out as well? it has a copper washer that goes between that and the housing

#5 09-29-2007, 02:35 PM

Ideally, the copper washers should be replaced every time you change the filter.

Your reciprocating piston, compression auto-ignition, diesel engine burns a specific fractional distillate of hydrocarbon mixture fuel oil (mostly petroleum) ranging from C10H20 to C15H28.

kerry · #6 09-29-2007, 03:04 PM

Since the engine is an OM61X which means 'Oil Motor', it is technically correct to call the fuel 'oil'. There's diesel motor oil and diesel fuel oil. The first goes in the crankcase and the second the fuel tank. Putting the second in place of the first will cause more problems than putting the first in place of the second.

TheDon · #7 09-29-2007, 03:12 PM

Quote:

Originally Posted by ForcedInduction

Ideally, the copper washers should be replaced every time you change the filter.

Your reciprocating piston, compression auto-ignition, diesel engine burns a specific fractional distillate of hydrocarbon mixture fuel oil (mostly petroleum) ranging from C10H20 to C15H28.

Ideally yes, but who does? I don't have a spare so I just anneal it and sand it.. works fine every time

might I say my old filter was coated in a nice film of black diesel fuel oil stuff... as well as my clear filter.. which I thought was clogged but it was the fuel... time for some biocide.

toomany MBZ · #8 09-29-2007, 06:58 PM

The crush washer is used on some engines. One of mine did, I went to the local hardware store, and got a composite washer, no more leak. Just remove bolt, and slip on washer.

jkoebel · #9 09-29-2007, 10:43 PM

Quote:

Originally Posted by TheDon

its fuel... fuel oil is for furnaces.. same thing

when you removed the spin on did you take the big banjo bolt out as well? it has a copper washer that goes between that and the housing

big banjo bolt = what screws into the top of the filter, yeah?

I did, took it all the way out, but didn't notice a washer anywhere.

I'll look again tomorrow, though -- I plan to remove and re-tighten and stuff.

Does that bolt need to be oriented in a certain manner, like, does it have a way it has to point in order to flow correctly?

TheDon · #10 09-30-2007, 12:51 AM

nah the bolt is fine... but no copper washer is probably causing the leak

jkoebel · #11 09-30-2007, 10:25 AM

Quote:

Originally Posted by TheDon

nah the bolt is fine... but no copper washer is probably causing the leak

I'll look around, then...I'm convinced it didn't have one in the first place, though.

Palangi · #12 09-30-2007, 11:04 AM

Not all years had a copper washer.

Some years have 2 (different sized) o-rings on the fuel filter bolt. They may be petrified if they have never been changed.

jkoebel · #13 09-30-2007, 11:07 AM

Quote:

Originally Posted by Palangi

Not all years had a copper washer.

Some years have 2 (different sized) o-rings on the fuel filter bolt. They may be petrified if they have never been changed.

Yes that's what mine has. And I received a single O-Ring that doesn't look the size of any of them, with the filter change kit.

Palangi · #14 09-30-2007, 11:17 AM

Part numbers here:

Fuel leak...coming from fuel filter bolt?

Post # 22

jkoebel · #15 09-30-2007, 04:02 PM

I lied, it does have a crush washer. I just didn't see it was its own part because it was so encrusted on.

I took it off, cleaned it up, and its still leaking from there...guess I'll be ordering a new one.