CAV/Delphi pre-filter bowl drain screw seal

[blackrose]

I'm not sure what happened to my recent thread on this, seems to have disappeared? Anyway, I bought some flat rubber washers from eBay to seal the drain plug on my water trap/separator but it's still leaking. The seal was 14mm OD/6.3mm ID x 1mm and it seemed to fit the drain screw very well but it doesn't work. I suppose I need to buy the correct part so I called Filtermania today and they're telling me they don't stock them anymore despite it being on their website. I'll give ASAP a call now but don't really want to hand over my card details to them again! Any other outlets where I could get a few of these seals?

[Alan de Enfield]

4 minutes ago, blackrose said:

I'll give ASAP a call now but don't really want to hand over my card details to them again! Any other outlets where I could get a few of these seals?

If you order by phone, then ASAP do not put your details on the internet where they can be hacked.

(I was part of the 'scare' a week or two ago, but, had paid by card over the phone and they explained - long story short - that I was in no danger)

[Boater Sam]

Not questioning your post. BUT as the screw is the lowest point, any leak from a seal on the body or unions will find its way down to the drain screw.

Diesel is a creeping fluid, it is hard to spot where it comes from.

Dry every surface, wrap a tissue, preferably coloured, around the body, not the screw, to establish exactly where it is coming from.

Edited October 30, 2018 by Boater Sam

[Robbo]

11 minutes ago, Alan de Enfield said:

If you order by phone, then ASAP do not put your details on the internet where they can be hacked.

Using the phone to give card details is much much safer!   /s 

[blackrose]

3 hours ago, Boater Sam said:

Not questioning your post. BUT as the screw is the lowest point, any leak from a seal on the body or unions will find its way down to the drain screw.

Diesel is a creeping fluid, it is hard to spot where it comes from.

Dry every surface, wrap a tissue, preferably coloured, around the body, not the screw, to establish exactly where it is coming from.

I'm pretty sure it's the drain screw seal as it only started leaking after a recent engine service. The old seal wasn't the correct one. At least it wasn't flat and it was a bit mashed.

I used my phone the last time I ordered from ASAP. I've never used their website for ordering. My bank still had to cancel my card in the end.

[blackrose]

Bleedin' ASAP Supplies! They want £1.44 + VAT for a single rubber washer. That's ok, even though it was only 22p on the Filtermania website, but then they also want £3.95 + VAT to put it in an envelope and stick a stamp on it. It would end up costing £6.46 for one washer! ? I said I don't mind them making profit on the part but didn't understand how they justify my making a profit on the postage. I'll find it somewhere else. I won't use ASAP again on principal. First they cause me a lot of trouble and then the try to rip me off! The decent thing for them to do would be to send me one FOC as a gesture of goodwill after the hassle they caused me with my bank card. CNUTS!

Edited October 30, 2018 by blackrose

[Boater Sam]

Have you got an old  o ring from a fuel filter? The small one that goes under the bolt head? Or a hardware shop, they will have a box full of all sizes of o rings. Paying that amount of cash for a 2p o ring is crazy.

There is nothing special about this seal, even wrapping the screw with PTFE tape will work.

[WotEver]

Aldi occasionally sell a plastic box full of assorted O rings for a couple of quid. 

 

Might be worth a check. 

[blackrose]

35 minutes ago, Boater Sam said:

Have you got an old  o ring from a fuel filter? The small one that goes under the bolt head? Or a hardware shop, they will have a box full of all sizes of o rings. Paying that amount of cash for a 2p o ring is crazy.

There is nothing special about this seal, even wrapping the screw with PTFE tape will work.

I don't know if it will. It needs to be a flat washer and I already tried a flat rubber washer which looked like it was the right size for the screw, nice and snug on the screw and sat nicely on the flange. I don't think PTFE tape will work as the screw thread has a flat on one side. Out of interest, is PTFE compatible with diesel?

29 minutes ago, WotEver said:

Aldi occasionally sell a plastic box full of assorted O rings for a couple of quid. 

 

Might be worth a check. 

Thanks, but access to assorted o-rings is not the issue. I have plenty onboard but it looks like it needs to be the correct one.

 

The ironic thing is that when I replaced the vetus water trap with the CAV/Delphi unit I thought it was going to make things easier.

Edited October 30, 2018 by blackrose

[Ex Brummie]

Not totally familiar with this unit, but are you putting the seal straight to the bolt? If so, you will have more luck if you put a metal washer between the bolt and seal. When you turn the bolt against the seal, it is easily distorted, especially if overtightened. This is a common cause of leakages on things like oil filters. A standard tap connector seal or an 'o' ring should suffice. Also make sure the mating face is clean and flat.

Edited October 30, 2018 by Ex Brummie
fast finger!!!

[bizzard]

1 hour ago, WotEver said:

Aldi occasionally sell a plastic box full of assorted O rings for a couple of quid. 

 

Might be worth a check. 

A slice of Aldi pork sausage would do the job. The skins on em are everso tough.

[Boater Sam]

The problem with using a washer as well is that the flat and the thread on the screw extends up to the head. This is probably the reason an o ring will not work.

Can you find a machine screw with the right thread and use an o ring on that?

Edited October 30, 2018 by Boater Sam

[Scholar Gypsy]

This thread reminds me why I never use the drain on my pre filter.  I just take the whole thing to bits to replace the filter element....

[BruceinSanity]

Midland Chandlers sell them, but you’d still end up paying postage unless there’s one within reach.

[adrianh]

Has the sealing face been damaged by the 1st washer/arrangement?

Rubber seals will need to be diesl resistant ie nitrile rubber not natural rubber as often used in the plumbing world

PTFE is ìnert to most things so can be used.

If this is a metal bowl filter a soft copper washer is best, pm me with size an I will see what I have

 

 

[blackrose]

12 hours ago, Ex Brummie said:

Not totally familiar with this unit, but are you putting the seal straight to the bolt? If so, you will have more luck if you put a metal washer between the bolt and seal. When you turn the bolt against the seal, it is easily distorted, especially if overtightened. This is a common cause of leakages on things like oil filters. A standard tap connector seal or an 'o' ring should suffice. Also make sure the mating face is clean and flat.

I think you need to see the screw to understand. It has a flange for the flat o-ring so no need for a metal washer. As I explained, a standard round section o- ring won't work and I've already tried a flat rubber washer which fitted the screw.. I'll try to find a picture.

11 hours ago, Scholar Gypsy said:

This thread reminds me why I never use the drain on my pre filter.  I just take the whole thing to bits to replace the filter element....

Yes if I get this sorted out that's what I'll do in future

11 hours ago, adrianh said:

Has the sealing face been damaged by the 1st washer/arrangement?

Rubber seals will need to be diesl resistant ie nitrile rubber not natural rubber as often used in the plumbing world

PTFE is ìnert to most things so can be used.

If this is a metal bowl filter a soft copper washer is best, pm me with size an I will see what I have

 

 

Thanks. I think it's 14mm OD 7mm ID but I will check it again. 

 

Found a picture of the screw. What you can't see is the flat along one side of the thread which means PTFE won't work.

Edited October 31, 2018 by blackrose

[WotEver]

I wonder what the flat is for?  As someone else suggested, any reason why you couldn’t use a normal bolt?

[Scholar Gypsy]

1 minute ago, WotEver said:

I wonder what the flat is for?  As someone else suggested, any reason why you couldn’t use a normal bolt?

I guess it allows you to drain the water/etc out without fully removing the bolt.  If you don't want to use it as a drain then you are right an ordinary bolt would be fine. 
 

(On my earlier post: my unit is on the tank side of the pump, and so operates at negative pressure, with a risk of sucking air in. It is above the tank which means that if you drain it is quite a faff to bleed it. In fact I never use the bleeding point either, but suck all the air out through the lift pump and let it out via the bleed point on the top of the filter bolted on the engine. Takes about 30 seconds....)

[Dr Bob]

1 hour ago, blackrose said:

I think you need to see the screw to understand. It has a flange for the flat o-ring so no need for a metal washer. As I explained, a standard round section o- ring won't work and I've already tried a flat rubber washer which fitted the screw.. I'll try to find a picture.

Yes if I get this sorted out that's what I'll do in future

Thanks. I think it's 14mm OD 7mm ID but I will check it again. 

 

Found a picture of the screw. What you can't see is the flat along one side of the thread which means PTFE won't work.

The 'flat' only goes part way up. There is enough of the thread at the end the wrap ptfe tape round.

My bowl has a slight weep. Take a 2L PET bottle. Cut off the top. Juggle it under the bowl and support via cable ties. What looks like a weep is actually about 2cm3 a year. I'll sort it this winter.

[X Alan W]

The aero version of that type of drain uses a "Dowty"  washer metal ring with rubber insert should be able to source from any Hydraulics servicing set up

[Alan de Enfield]

11 minutes ago, Dr Bob said:

Take a 2L PET bottle. Cut off the top. Juggle it under the bowl and support via cable ties. What looks like a weep is actually about 2cm3 a year. I'll sort it this winter.

My Pet shaped bottles are a bit less than 2 litres, do you think they will do the job or should I try and find a bigger one , or, would a non-pet shaped bottle work ?

 

Edited October 31, 2018 by Alan de Enfield

[Dr Bob]

15 minutes ago, Alan de Enfield said:

My Pet shaped bottles are a bit less than 2 litres, do you think they will do the job or should I try and find a bigger one , or, would a non-pet shaped bottle work ?

 

You may feel better if you get one with coke in it?

[Alan de Enfield]

7 minutes ago, Dr Bob said:

You may feel better if you get one with coke in it?

Yer - Man - Its Great

Doesn't it make you sneeze ?

[Dr Bob]

40 minutes ago, Alan de Enfield said:

Yer - Man - Its Great

Doesn't it make you sneeze ?

Dunno., but it makes it difficult to get to the stern gland nuts.

[bizzard]

I've drained hundreds of these off on vehicles and boats and I can't remember there being any that leaked even re-using the old sealing washer. Even found em with the wrong ordinary O rings on and not leaked. I reckon there's an imperfection or distortion on one of the mating surfaces, perhaps the flat or flute on the screw has been machined a touch too far and encroached on the bolts flat surface, I think you said it was'nt leaking before you undid it though,  very strange.  No doubt a Doubty washer will fix it. Examine the bowl first though for any hair line cracks, especially around the screw hole.