Leaking fuel unions

Ive had the metering head off and after putting it back on, along with a new fuel filter i have one or two weeping banjo bolts. Ive cleaned up all the copper washers with some 1200 wet and dry and then rinsed them but im still getting a weep on the fuel filter ones.
Any ideas? They are all tight but can you get copper washers but with rubber seals? Its only ever so slight but a leak none the less.

Try new washers, if they are like sump plug ones you are only supposed to use them once.

https://www.ebay.co.uk/itm/Kit-5-COPPER-WASHER-KIT-FOR-BOSCH-K-JETRONIC-fuel-metering-head-distributor/223243647986?hash=item33fa5bbbf2:g:7b8AAOSw-4RadekW

The thing about re-cleaning and using old  crush washers, there is a step that you didn't mention, and it is an important one.

You have to slighty clean them with Sandy type paper. to remove any burrs.

Holding them lightly with a pair of pliers, you heat them up with a Ciggie lighter or propane torch (butane ones work too), till they change from the shiny copper color  dull.  This reconditions the metal or re-annuls it.

I did this quite a lot on my Diesel, IIRC I only sourced new ones after about the 5th or 6th reconditioning. I also used a light coating of Fuel Rated RTV on both sides as I didn't want any leaks whatsoever.

I did clean them up Brian with 1200 grit wet and dry paper so there wasn't any burrs or scatches in the metal. One of the unions to the fuel filter has brand new washers that came with the filter so its seem odd that new ones would leak.
I will try the lighter method to see if it helps. Surely there must be a fuel resistant rubber and copper washer so the possibility of leaks is much less.
Until then i guess new ones as mentioned aswell will probably be needed

It is the 75 PSI that requires the crush washers.  The digifant @ 45 psi doesn't.  I got used to them on my Diesel.  Thought it was over kill on the input to the filter.

did put sizes of new  copper sealing washers before, have a search…
but here is a link to dowty/bonded seals.
Gaskets & O-Rings | Rubber O Ring Seals | RS

arghhhhh phone…spellchecker

Kenneth Cartwright said

did put sizes of new  copper ealing washers before, have a search…
but here is a link to dowty/bonded seals.
Gaskets & O-Rings | Rubber O Ring Seals | RS

Eh lol

Sent from my SM-G955F using Tapatalk

Dowty washers, thats the ones i was thinking of. I managed to source a full set of new copper crush washers so i will give them a try on the leaking unions but if one fails again then the rubber sealing ones might be the best way forward