Diesel primary filter leaking

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Kyle2

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I have a CAV type of fuel filter on my boat, and there is a persistent and annoying leak of diesel fuel from around the centre bolt of the filter assembly. I have tried replacing the copper washer under the bolt and the leak remains. Has anyone else had this experience and managed to cure it? I have tightened the bolt as far as I think I can, but am wary of over-tightening. Would a different type of washer be better - e.g. fibre? Helpful suggestions gratefully received.
 
There is a rubber "O" ring sealing the bolt not a copper washer - well there is on my CAV filters, goes on the bolt between the steel washer and the lower filter casing. The "O" ring comes with the replacement filter. Sounds like you have one of the setups produced by Messers Bodgit and Co. /forums/images/graemlins/grin.gif
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Artificial Intelligence is no match for Natural Stupidity.
 
My Yanmar 1GM10 seeped from the fuel filter copper washer and I didn't dare tighten it with any more force. I went to the Yanmar dealer for a replacement copper washer and was given the genuine part which turned out to be a plastic washer. Just a gentle nip and the seepage has disappeared.
 
Being both a diesel engineer and yachtsman, in this particular instance I would opt for fibre washers over copper. As "Respect" noted, just a gentle nip. Don't over tighten. There is no need to use sealant.
I personally keep a selection of fibre washers aboard for annoying little leaks.
 
There should be a small o ring as well as a steel washer under the head of the bolt.
You do sometimes get a copper one as well but you do need the o ring
Replace the o ring first before you do anything else. It fits under the washer into the slight recess in the filter body top that is under the head of the bolt.
Most good filter replacement kits have the o ring but some dont and just supply the big rubber seals that seal the actual filter to the top and bottom bowls.
Hope this helps
Joe
 
you need the small o ring in place. many replacement filters do not supply these (annoyingly).
 
Junk the CAV and convert to a Racor spin on. Dead easy to change, no sheaf of seals and washers to sort. The only downside is that the filters are more expensive than CAV, but I think it's worth it. ASAP are the people to contact.
 
I would avoid sealant. I had a very nasty experience where sealant got into the injector pump and injector of a 1GM.

CAV filter properly put together should be absolutely fine. I like being able to get filters cheaply anywhere.
Key thing is to locate it where you can see what you are doing to reassemble it!
 
Joe/martin1001... Without wanting to confuse the issue, which is primarily fuel leaking past the head bolt on the housing. Over the years I've come across different castings/housings for these filters, some with a machined face and others recessed. CAV would probably deny this but it's fact. Lucas/CAV are no more and Delphi Automotive Systems using their Delphi HDF-296 filter supply an O ring. It is necessary to check the housing for the recess to fit this. If there's a machined face fit a fibre washer.
 
Thanks for the suggestions. The filter I have does not seem designed to accept the small rubber washer. The lower part of the body, where the centre bolt screws in, does not extend up as far as the top half of the body, therefore the small rubber washer would not be compressed against anything. I think I will try a fibre washer next, instead of the copper one.
 
I have exactly the same problem.... my solution has been to place an empty tesco salad bowl under the filter to capture the drips !!

I keep meaning to try and fix it permanently but my Yanmar 2GM20 is such a pain to bleed afterwards, I keep putting the job off but all the advice is extremely useful for the next attempt at the end of the season.

Cheers, Andrew
 
Copper washers are correct for pressure systems where the retaining nuts and housing will take a reasonable torque. This does not apply to your filter and a plastic/fibre washer is the correct fitting.

Incidentally, for another day, you can refurbish your copper washers by heating them in a gas flame!

PWG
 
[ QUOTE ]

I keep meaning to try and fix it permanently but my Yanmar 2GM20 is such a pain to bleed afterwards, I keep putting the job off but all the advice is extremely useful for the next attempt at the end of the season.

Cheers, Andrew

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why is your yanmar a pain to bleed? I loosen the bleed nut on top of the secondary filter a couple of turns, start her up and wait for the bubbles to finish - don't bother with hand lift pump. when she has finished bubbling gently tighten screw head again and jobs a good 'un /forums/images/graemlins/smile.gif
PS have something strategically positioned underneath to catch the small amount of diesel that spills before it enters your bilges
 
[ QUOTE ]
Thanks for the suggestions. The filter I have does not seem designed to accept the small rubber washer. The lower part of the body, where the centre bolt screws in, does not extend up as far as the top half of the body, therefore the small rubber washer would not be compressed against anything. I think I will try a fibre washer next, instead of the copper one.

[/ QUOTE ]Oh dear - I'll try to explain again - Hold the bolt in one hand and fit the steel washer with the other - slide the washer all the way to the head of the bolt then fit the "O" ring and slide it all the way up to the washer THEN insert the bolt, washer,"O" ring into the base of the filter. The "O" ring will be compressed between the washer and the base of the filter.
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Artificial Intelligence is no match for Natural Stupidity.
 
I fitted a fibre washer yesterday, and eureka, the leak has gone. Incidentally, I don't think the rubber washer mentioned before would fit under the bolt head, as there is no recess in the casting. I guess that these filters come in slightly differing designs. Thanks all for your help.
 
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