Oil pressure take off - leaking seal washer

[Robbie.watson@uk.bp.com]

Hi all
Went for a spin today and when I got home noticed a fair bit of oil had escaped.. on investigation it’s leaking from the brass union at the back of the crankcase that is the oil pressure take off. I have a fibre washer there sealing but it seems that when it gets hot it goes hard and starts to leak. What do people use to make a good deal here? A washer of different material or just some gasket glue under the union??
Cheers
R

[Duncan Grimmond]

IIRC it's a BSP thread (tapered ?) I'd use PTFE tape.

[bob46320]

You don't need much sealant of any kind as the running pressure is around 2Psi and even when cold, its only about 12 Psi

[Robbie.watson@uk.bp.com]

IIRC it's a BSP thread (tapered ?) I'd use PTFE tape.

Unfortunately not tapered.. May try the ptfe tape though?

[Stuart Giles]

I use Dowty seals for the flat seatings of parallel BSP fittings. The oil pressure take off is 1/8" BSP. Some for sale here: 
https://www.ebay.co.uk/itm/BSP-Dowty-Hyd...Wm0cnvKJvw#

I'd be wary of using PTFE tape on the oil system in case some of the PTFE ended up obstructing an oil jet.

[Robert Foreman]

All you need to do is remove the union, clean it and the thread in the crankcase and refit with the fibre washer and a few drops of loctite screwlock which will stop it coming undone and also create a seal.

[Ian Williams]

Dowry seals as Stuart suggests are excellent and Loctite may also seal it, however in the case of this union, provided everything is in good condition I have never had an issue with leaks. I would take it apart and inspect for a reason, are you sure it is coming from under the washer not through the conical seating?