S series oil pump questions

[RobMcP]

I'm having this common problem of air in my oil lines. Dowty washers was suggested so I've bought some. My issue is the washers are 2mm thick so there's very little thread left to screw into the pump. Can anyone share a link for some slimmer washers or is this how they come?
I'm also curious of whether the pump requires refurbishing with new rubber seals? Might this help with the air bubbles and is it something that I, with my limited mechanical skills, can do?

[scouse]

I bought mine from earl"s
https://www.earls.co.uk/earls/preassemb ... ekits.html

They work fine

[Rickm]

You're correct about the Dowty washers being thicker than the standard ones.
Most folk love them, but it's not often mentioned that you do need threads in very good condition to use them without risk of stripping.

[doodah]

I had a problem with my H1b accumulating air in the lines. Someone had taken the check valves apart, but failed to re-align the banjos properly, so that they had a twist on them when presented to the oil pump. i.e. one side of the banjo was touching the pump, the other side was raised away from the surface. Even though you could tighten them down they still leaked in air, particularly on the short fat oil line. Check your banjos are parallel / flush when presented to the oil pump (without being bolted down).

[doodah]

I have also used the plastic washers fitted to the Suzuki GT series bikes - they work great - they are thicker than the Kawa aluminium washers but thinner than the Dowtys. The part number is on this ebay listing - you must be able to get them cheaper elsewhere https://www.ebay.co.uk/itm/124068483682 ... SwcrVeNbF5

[Haggis]

I buy mine from Rhondama in Loughbrough, they are not cheap 54p +vat they are 1m/m thick same as the originals

[RobMcP]

Thank you so much for all of your suggestions. I'll order some thinner dowtys or the plastic GT ones and hopefully this will cure.

Tell me, the inlet banjo has a small and larger side. I'm guessing that the dowty washer might not seal here and I will still want a crush washer? Is the crush washer the same dimensions as the others? The parts manual says yes, just seems a little odd to me

I can't remember having these issues when I was riding this bike in the 80's so thought it might be down to perished rubber within the pump letting in air. This isn't the case then?

[mraxl]

Tell me, the inlet banjo has a small and larger side. I'm guessing that the dowty washer might not seal here and I will still want a crush washer? Is the crush washer the same dimensions as the others? The parts manual says yes, just seems a little odd to me

I have found that 1/4" will seal both but 6mm will only seal outlet.