Leaking, seeping fuel filter on a perkins engine

[Obi]

I have a Perkins engine with a primary filter. After picking up some slush from the bottom of the tank, I overhauled the fuel filtering system, including new primary filter and o ring seals. The part I got was from partco, a unipart, but looks the same.

After fitting, priming etc, I found that the seals were leaking. I tried the old seals, which I had previously removed, with the new filter, it still seeped out of the large rings, so I replaced the old filter and old sealing rings to see if this improved matters. It was then worse.

I dont want to over tighten. Can anyone suggest anything? It really looks like all the seals and filters are lining up and fitting into thier appropiate reccesses.

The one o ring I didnt change is the one in the filter housing - Ill try and explain: I removed the filter element, there are 2 large seals which sit top and bottom of the filter element, there is a third small one which fits around the retaining bolt and inserts in the top of the housing, there is a fourth which bits around the guide the filter element fits over, this is the one i didnt change, and I dont think it can be responsible for fuel seeping from the top or bottom of where the housing and element meet.

I have read on this forum about using fibre seals to solve seeping filters. Is this really a silver bullet/magic bean for this problem? If so, where can I get them?

Any advice please?
Thanks
Obi

 

[samwise]

Sounds like you are not tightening up enough. There is always a fear that you will strip the thread and you will have a major leak. assuming there is no damage or dirt in the seatings and that the seals have not been damaged or cut, nipping up the bolt until the leak stops ought to solve the problem. For myself, I hated those filters with the multiple seals that I went for a converter unit on the filter housing to take Racor spin on filters. Dead easy, just spin on like an oil filter and hand tighten. My thought was that I may need to do this job in the dark and in a seaway, so it should be as foolproof as possible. The Racors are more expensive, but I think they are worth it for the ease of fitting ( less mess too)

 

[savageseadog]

Lots of people moan about these filters which I assume is a CAV296 type, I've never had a problem ever. Your leak will be caused by over or under tightening or possible damage to the mating surfaces. Don't use any magic goo, The O ring fitted to the spigot which engages to the hole in the filter is the most important one as it separates the filtered fuel from the unfiltered.

 

[boatmike]

Lots of people moan about these filters which I assume is a CAV296 type, I've never had a problem ever. Your leak will be caused by over or under tightening or possible damage to the mating surfaces. Don't use any magic goo, The O ring fitted to the spigot which engages to the hole in the filter is the most important one as it separates the filtered fuel from the unfiltered.

I agree, and the problem is often that some ham fisted bar steward has wrenched the bolt up so tight in the past that the housing gets distorted. No end of careful tightening thereafter will stop the leak

 

[ianat182]

Leaking Fuel filter.......

If you are taking the main body apart to re fit the seal just do a quick check that an old sealing ring is not already present. I found this had been done on my old Volvo engine fuel filter,and would you believe it ,the same on the Oil filter housing ,so the filter seal was not seating properly in the groove. Easily missed as the groove looks as though it is clear but the older seal has been compressed.



ianat182

 

[PeterGibbs]

If you are taking the main body apart to re fit the seal just do a quick check that an old sealing ring is not already present. I found this had been done on my old Volvo engine fuel filter,and would you believe it ,the same on the Oil filter housing ,so the filter seal was not seating properly in the groove. Easily missed as the groove looks as though it is clear but the older seal has been compressed.



ianat182

Just want to emphasise the importance of removing all old seals - even if they look good; The one that lies wedged in the bottom of the top housing, which the filter mates with from below, is critical. Use no heavy instruments to remove this seal - damage to the surfaces will render the unit inoperable.

The filters come with lots of seals for different purposes - don't fall into the trap of trying to find a home for each one if the original setup didn't require it.

Finally, the bolt on my gear has a metal washer to spread the load when tightening - no rubber seal. You will never apply sufficient tightening pressure to create a seal if you are using a rubber washer under the nut of the securing bolt.

The torque you apply to seal the gear is the old rule - turn with a small spanner until firm, then no more than 1/4 more turn to finish off.

Sometimes, despite all these precautions, it is necessary to remake the primary filter seal. Sigh deeply, like we all do, and patiently start again. Good luck!

PWG

The top bolt requires

 

[Refueler]

My CAV filter is still using the same seal rings from 2 filters back ... I make sure that when removing filter / fitting new that I do not disturb the old seals in any way.
I have the new seal rings in the box with new filters ... so if it does leak - I can soon fit them.

Now to OP - be careful about the filter you're given. If it's same CAV as mine - you can be given a wrong filter - same size but different fuel flow route. Correct filters for me have sections out of base of filter like orange segments - so that when bottom is added and all bolted up - fuel can flow through. Shop gave me a pattern filter before last trip which didn't have orange segment holes in bottom ... but what appeared like a rim gap around inner circumference ... this would not work and fuel pressurised the casing and leaked. Only when I removed and compared did I note the difference. Put my 'other' spare in - the orange segment hole type and all was well again.

Just a thought.

 

[pappaecho]

On my Evasion 32, the 4108 was fitted with a primary filter and when we changed the engine a couple of years ago we changed the filter, which included a filter and a water separator, but in every other respect the two units were identical, and clearly made to be so. Mine came from a lorry parts supplier and I think also it was Partco. I think that the new unit cost about £20, so I would take the plunge for a complete replacement.

 

[DavidNB]

Its safer to change all the seals, as you never know who else might service it next time and eventually they go hard and crack. I've always used a small electrical screwdriver to remove the old seals, be careful on the large upper one, dig it in to middle and pull long ways so blade does not touch the head and thirdly the large rings are different sizes.



EX HGV/PSV Tech

 

[PetiteFleur]

If you are taking the main body apart to re fit the seal just do a quick check that an old sealing ring is not already present. I found this had been done on my old Volvo engine fuel filter,and would you believe it ,the same on the Oil filter housing ,so the filter seal was not seating properly in the groove. Easily missed as the groove looks as though it is clear but the older seal has been compressed.



ianat182

I also found this problem when I had a leaking filter, due to it;s position, it wasn't until I removed it and checked on the bench that I found I had an extra sealing ring in the groove. When all cleaned up with a new sealing ring it was OK.

 

[Obi]

Thanks everyone, really appreciate it.

What it was, it was the first time Ive ever done one (Im a new owner), and I had placed the large top seal into the filter element itself and not into its recess in the filter housing. As such it wasnt actually sealing the lip on top of the filter.

All done now, tanks cleaned, new filters x2, breather unblocked, diesel filtered and treatment for the damned diesel bug added.

Onwards and upwards!

Obi