Walsh 2LW Fuel Filter - What Thread?

[mark99]

Ooooh err. Text sent.

[jonesthenuke]

That's an interesting view. The rubber is moulded to be thicker than the steel backing ring. There is no requirement to "crush" the steel ring, and that is no how they are designed to work. Consequently they work fine at low pressure.

see this original Dowty sales material. Quote "effective and reliable face sealing at high and low pressures"

 

http://www.potterassoc.com/pdf/bonded_seal_information_and_sizing_chart.pdf

[mark99]

Thanks Gareth.

 

The part is now mine.

[by'eck]

That's an interesting view. The rubber is moulded to be thicker than the steel backing ring. There is no requirement to "crush" the steel ring, and that is no how they are designed to work. Consequently they work fine at low pressure.

 

 

see this original Dowty sales material. Quote "effective and reliable face sealing at high and low pressures"

 

http://www.potterassoc.com/pdf/bonded_seal_information_and_sizing_chart.pdf

 

Sorry but they simply didn't work for me on (several) fuel unions despite the sales pitch, new plain copper ones did.

 

I suspect they would work between perfectly machined, flat and parallel surfaces, but more often than not you don't have that luxury, so you need a seal that can adapt.

 

In their common high pressure application, the thin area of rubber is pushed hard to form a seal, without this it seems you are reliant on the tiny surface area of rubber to form the seal, albeit proud of steel part, which as you suggest forms no part of the seal.

Edited May 18, 2015 by by'eck

[frangar]

Thanks Gareth.

 

The part is now mine.

Well that all worked out rather well didn't it!....you can share the pic now if you want to!! Unless you have brought all the parts?.....

 

Cheers

 

Gareth

[mark99]

Well that all worked out rather well didn't it!....you can share the pic now if you want to!! Unless you have brought all the parts?.....

 

Cheers

 

Gareth

 

I've not got it yet. Paid but awaiting postman.

 

NB does anyone know if the whole unit bolts direct to engine without packing or seal (can't see it needs a seal). I'm not near the engine so can't check and the Gardner Parts book does not seem to show a part sandwiched between engine and fuel filter assembly (fuel assembly = part 6/103).

Edited May 19, 2015 by mark99

[LEO]

 

I've not got it yet. Paid but awaiting postman.

 

NB does anyone know if the whole unit bolts direct to engine without packing or seal (can't see it needs a seal). I'm not near the engine so can't check and the Gardner Parts book does not seem to show a part sandwiched between engine and fuel filter assembly (fuel assembly = part 6/103).

 

Hi,

 

I looked at changing the same assembly on my 2LW (a Walshes unit), looks easy but one bolt seems to be partly obscured by a blue hose, making easy access withdrawl difficult.

 

Drain the cooling system?.

 

I would look at ways of leaving the backplate in place and extracting the broken section on the stud.

 

Hope that helps.

 

Mike

[Timleech]

It's just held to the front of the engine with two small bolts.

 

Tim

[mark99]

 

Hi,

 

I looked at changing the same assembly on my 2LW (a Walshes unit), looks easy but one bolt seems to be partly obscured by a blue hose, making easy access withdrawl difficult.

 

Drain the cooling system?.

 

I would look at ways of leaving the backplate in place and extracting the broken section on the stud.

 

Hope that helps.

 

Mike

 

 

Mike - the threaded female boss on the backplate is broken; the stud is ok. If I then screw the stud right into the remaining bit of the boss, the stud is too short to get the wing nut on - hence temporary bodge of extra long stud.

 

However if new part arrives in time - happy days.

 

Thanks Tim.

Edited May 19, 2015 by mark99

[mark99]

If you look at the photo's of both sides of the fuel filter assembly you can see I have two ways of feeding fuel into Garnder fuel filter body - via gravity day tank or lift pump from floor lower tank (nb both these fuel tank feeds have their own seperate agglomerators).

 

Anyway the question re the various connections into the Gardner fuel filter (entry and exit pipes) is:

 

what sealants/sealant mediums do I need to remake these joints into the replacement filter assembly?

 

 

I'm not on the boat so can't check and dont want to drive 100 miles to find out I've forgotton some small thing to seal a joint!

 

You can see the grey inlet and outlet fuel pipes (feed from lift pump and outlet to HP pump), the spiral copper feed (inlet from day tank) and the chrome (spill rail).

 

 

 

Edited May 19, 2015 by mark99

[MoominPapa]

 

 

 

Sorry but they simply didn't work for me on (several) fuel unions despite the sales pitch, new plain copper ones did.

 

I suspect they would work between perfectly machined, flat and parallel surfaces, but more often than not you don't have that luxury, so you need a seal that can adapt.

 

In their common high pressure application, the thin area of rubber is pushed hard to form a seal, without this it seems you are reliant on the tiny surface area of rubber to form the seal, albeit proud of steel part, which as you suggest forms no part of the seal.

 

I've found the opposite. Several low pressure fuel joints that wouldn't seal with new and/or freshly annealed copper washers, are now perfect with Dowty washers instead, including the bleed screws on the injection pumps. Did you use the self-centering Dowty washers, which has an extra bit of rubber in the middle to ensure that the rubber sealing "wings" are in the correct position?

 

MP.

[jonesthenuke]

It may be worth reworking the coil in the feed from the day tank to avoid the air trap? Just make the coil horizontal so that it automatically vents to the filter body?

[Roadsteam]

Metal on metal pipe joints no goo needed unless its taper threads then a turn of PTFE tape.

[furnessvale]

 

 

You can see the grey inlet and outlet fuel pipes (feed from lift pump and outlet to HP pump), the spiral copper feed (inlet from day tank) and the chrome (spill rail).

 

 

 

Can't see a thing without my sunglasses!

 

George ex nb Alton retired

[jenevers]

Ebay, use a viton or nitrile to ensure long term resistance to the fuel..

 

see previous post below:-

 

Posted 02 June 2014 - 04:16 PM

 

Problem solved. Fitted an O ring instead of the paper/cardboard(?) gasket supplied with the filter and now it's no problem at all.

I used 69 mm by 3.5 mm cross section nitrile ring.

 

 

Great idea. Is eBay item number:141201449324 what you mean?

 

Also, could you let me know the size of the Dowty seal you use under the nut?

Edited May 20, 2015 by jenevers

[jenevers]

 

 

Alan

 

My 1949 build, 1951 supply 3LW has the a big (bronze?) wing nut - I guess they, Gardner, did not expect any more than hand pressure to effect a seal let alone the chance of fracturing a fitting.

 

Alan

 

I have the same type wing nuts but have to use mole grips to tighten in order to avoid seeping at the gasket. Would hate to overdo it and end up shearing the female thread.......so o-rings for me from now on!

[mark99]

I got both 69mm and 65 mm nitrile rings (3.5mm xsection) and the 65mm look a better fit for the housing on mine. So might be worth trying a couple of sizes. The castings /finishes of these filter items are not good are they?

Edited May 20, 2015 by mark99

[jonesthenuke]

I got both 69mm and 65 mm nitrile rings (3.5mm xsection) and the 65mm look a better fit for the housing on mine. So might be worth trying a couple of sizes. The castings /finishes of these filter items are not good are they?

OK I was aiming to seal on the OD of the ring as follows. The gasket is 3" OD so 76.2 mm. 69mm ID Oring at 3.5 cross section gives 76 mm and thus should fit close within the outer edge of the housing groove Any pressure would thus push the ring out against the groove. Its worked for me but if the smaller ring works too that's another option.

[jonesthenuke]

Great idea. Is eBay item number:141201449324 what you mean?

 

Also, could you let me know the size of the Dowty seal you use under the nut?

That Ebay part should be fine. I am not on the boat at present, so you may want to confirm the thread size for the washer. If its 3/8" then a 3/8 washer (or 10mm). If the filter has not been sealing well in the past it will help to get the best surface on the sealing faces, either skim or use some fine wet and dry on a flat surface.

[jenevers]

That Ebay part should be fine. I am not on the boat at present, so you may want to confirm the thread size for the washer. If its 3/8" then a 3/8 washer (or 10mm). If the filter has not been sealing well in the past it will help to get the best surface on the sealing faces, either skim or use some fine wet and dry on a flat surface.

Thanks. I'll "wet or dry" surfaces next time I change filters and get o-rings & Dowty washers.

[mark99]

Well that went well, I just received the 3/8" BS Whitworth stud from the supplier and does not fit a supply of 3/8" BSW nuts I have. Looking at it hard it's 20 tpi not 16. Great.

 

I've made a complaint and demanded a proper 3/8" stud be sent 1st class.

 

They also sent me a 5/16 BSW stud which also is not BSW.

Edited May 20, 2015 by mark99

[mark99]

All fixed now and leak free. New stud cut to length, changed filter. Used dowty seals on both threads without issue did not have to use copper washers.

 

And yes Jones T Nuke I agree with you now Ive fitted them, the 69 mm nitrile o ring sets up a really good seal.

 

To anyone who has a leak with this unit try the 3.5 mm x section o ring and dowty seals.

Edited May 23, 2015 by mark99

[frangar]

Did the parts you ordered from that ad arrive?

 

Cheers

 

Gareth

[mark99]

Did the parts you ordered from that ad arrive?

 

Cheers

 

Gareth

Not yet. The cheque has been cashed (they would not accept a bank transfer) but nowt arrived yet. The temporary fix is so good I may leave it until the fuel filters are changed next.

[mark99]

Did the parts you ordered from that ad arrive?

 

Cheers

 

Gareth

 

Finally - yes. £80 quid.