Author Topic: fuel filter seal question  (Read 6447 times)

merrill

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fuel filter seal question
« on: November 15, 2008, 23:20:20 »
I started having a fuel leak at the fuel filter in the engine bay.
The fuel appears to be leaking from beneath the head of the bolt that secures the filter can.

When I removed the bolt I found a non metal seal, It broke apart in my hands.
I have a spare filter assy, so I thought I would pull the seal off of it. On the spare assy
there was a metal seal.

Is this supposed to be a metal or non metal seal.
The seal I am looking at is item 29 in the attached photo.
Also, If anyone knows the seal part number I need it.  The metal seal is leaking also.
Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

Benz Dr.

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Re: fuel filter seal question
« Reply #1 on: November 16, 2008, 07:38:58 »
It's definately metal. It's the same seal that you would find on the short ( C shaped ) water line near the thermostat housing that has two banjo bolts. It's also used on the banjo bolt on the oil lock line.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
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merrill

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Re: fuel filter seal question
« Reply #2 on: November 17, 2008, 00:29:17 »
Dan
thanks for the reply,  is there a torque value for the fuel filter bolt or just snug it down?

The reason I ask is I tried to get the bolt snug but not over tight and ruin the large rubber o ring
between the filter cup and top.

the metal seal from the other assy I had leaked fuel as well.
Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

Benz Dr.

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Re: fuel filter seal question
« Reply #3 on: November 17, 2008, 04:46:10 »
I've had trouble with that seal leaking and what I did was just turn the screw a bit more. They always leak at the small seal if they're not tight enough.
 The rubber seal is a square cut type and much harder than the one used on the oil filter housing. I generally use a new one during restoration work and replace them if there's a leak at that seal during regular maintance work. They can be hard to install as they tend to fall out. Use a bit of grease to hold it in place during assembly.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

wwheeler

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Re: fuel filter seal question
« Reply #4 on: November 17, 2008, 21:08:41 »
Matt,

My fuel filter bolt seal will occasionally seep like yours. I tightened it once which held for a few months and then began seeping again. I snugged it once again and now seems to be holding. I went ahead and purchased a seal ring just in case #007603-008109. I am pretty sure my 111 seal ring is the same as the 113 but confirm to be sure. I think if metal seal rings have been over compressed, they become too hard and will also crack. That may be the case with mine. I would replace it everytime when changing the fuel filter.
Wallace
Texas
'68 280SE W111 coupe
'60 220SE W128 coupe
'70 Plymouth Roadrunner 440+6

merrill

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Re: fuel filter seal question
« Reply #5 on: November 22, 2008, 20:44:38 »
I ordered and received #007603-008100 which is a copper seal ring.

installed new seal along with a new o ring and no leak.
Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

Iconic

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Re: fuel filter seal question
« Reply #6 on: November 01, 2011, 00:18:43 »
OK, this is an old topic, but can anyone tell me the torque spec for the bolt that secures the fuel filter can (bolt #28 in the picture in the first post)?
I have not been able to find it.
1970 280 SL Automatic, USA version, Grey-Blue (906G/906G), Blue leather (245)
1968 SS396 Camaro Convertible (owned since 1977 -- my first car :D)
1984 Porsche Euro Carrera coupe, LSD, SlateBlueMet/Blue
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1970 280 SL Automatic, Anthracite Grey-173G, Red Interior-132 - sold

wwheeler

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Re: fuel filter seal question
« Reply #7 on: November 01, 2011, 02:30:54 »
I don't think I have ever seen one. Bolts with seal rings don't have to be super tight. In fact, overtightening will cause the ring to "cold flow" and crack. My recommendation would be to snug it up well and look for leaks. If it is tight, it will only weep at worst. If it does weep, snug it up a bit more. Also be sure the seal ring mating surfaces on the bolt and the filter housing are smooth and burr free. A seal ring will leak if they aren't. I hope this helps.
Wallace
Texas
'68 280SE W111 coupe
'60 220SE W128 coupe
'70 Plymouth Roadrunner 440+6

ja17

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Re: fuel filter seal question
« Reply #8 on: November 01, 2011, 04:30:24 »
I like to use some grease on these metal seal rings before tightening. It helps the metal surfaces to mate-up smoothly without galling.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
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Iconic

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Re: fuel filter seal question
« Reply #9 on: November 01, 2011, 17:16:42 »
Thank you Wallace and Joe,
I got lucky with the grease, Joe. I used grease to hold the seal onto the bolt before I read your post. So, mine has grease.  :)
For the record, I tightened it up to about 4.5 ft-lbs (6.1 N-m) and it does not leak.
I'll keep an eye on it to make sure it doesn't start to leak.
Thanks again.
Mark
1970 280 SL Automatic, USA version, Grey-Blue (906G/906G), Blue leather (245)
1968 SS396 Camaro Convertible (owned since 1977 -- my first car :D)
1984 Porsche Euro Carrera coupe, LSD, SlateBlueMet/Blue
1998 BMW M-Rdstr Estoril Blue
1970 280 SL Automatic, Anthracite Grey-173G, Red Interior-132 - sold

wwheeler

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Re: fuel filter seal question
« Reply #10 on: November 01, 2011, 18:01:06 »
That's a great thought about using a little grease on the seal rings. I have noticed a few times seeing gall marks on the rings especially the aluminum ones. That will fix that!
Wallace
Texas
'68 280SE W111 coupe
'60 220SE W128 coupe
'70 Plymouth Roadrunner 440+6