Cleveland master cylinders - AN fittings for ports

[Ian Law]

I have a couple of used pull type Cleveland master cylinders (10-23).

The ports are threaded 7/16 - 20 and one cylinder came with a couple of AN833 elbows. At least I think this is what they are. Both master cylinders will be fully serviced before use.

I notice there is a black plastic(?) shaped washer that fits the outer "cup" in each port and is held in place with an aluminium AN nut that also locks the AN elbow to the port.

I have absolutely no experience of hydraulic brake systems and wonder if anyone could suggest where I might find a replacement for this odd little washer - if indeed it is required.

Instead of using this type of washer - or maybe in addition to it - I have thought about using "DEL fitting seals", as listed by Aircraft Spruce. Does anyone have any recommendations?

(I've attempted to post an "image" of my AN fittings, but suspect this might not appear in the post!)

Ian Law

[Ian Melville]

Despite the option to do so this forum does not allow pictures. Not sure if that is intentional or not.
Just post it as a URL instead.

[Dave Hall]

If you get the photo on the web, right click on it and select properties, you can find the actual photo URL. It should end with .jpg Copy it all into your post and click the Img box to add the bits each end so it appears automatically.

[Ian Law]

Many thanks, Ian & Dave!

[Ian Law]

Looks like I shall have to resurrect my earlier posting, in the hope of someone with an expert ( or, unlike me, even a basic!) knowledge of aircraft plumbing coming forward to assist with a solution.

Having now reached the stage where I need to finalise plumbing arrangements for my "Pull" type Cleveland master cylinders (10-23), I have found that the aforementioned hard plastic washers on the two port fittings ( which appear to be AN833 plus a plain AN lock nut) that came with my second hand wheels are in fact the only means of achieving a seal. They appear to be quite businesslike and I assume must be standard fittings.
Peering ( belatedly ) inside the ports reveals there are no "flared" sockets, so I can't rely on the flared end of the AN 833 fitting or the "DEL Fitting Seals" previously mentioned, to ensure good sealing. Threads are "parallel", not tapered, 7/16 x 20 inside the ports.

I need another pair of similar AN fittings, with "washers/seals", for the inlet ports. I can try re-using the pair of fittings that came with my wheels on the outlets.

I assume this type of port fitting must be common to many other Cleveland master cylinders, including the more usual "Push" types, but it does seem rather weird. I have a spare couple of similar master cylinders and they are identical.

Corresponding with Parker Hannifin in the USA is a bit hit and miss at the best of times. To be charitable, I expect they have much better things to do than deal with the likes of me!

Could anyone suggest where I might be able to find suitable port fittings, or plain aluminium AN nuts and suitable seals/washers/ "O" rings (not shown in my Aircraft Spruce catalogue)?

Ian Law

[Bill McCarthy]

What you have there is an encapsulated "O" ring. The metal washer part of it prevents the "O" ring from being forced out between the faces under pressure. A standard "O" ring that fits snugly over the thread and into the washer I/D will put it right. Make sure that the "O" ring material is compatible with the system fluid, is of the right cross section in order for it to be squeezed into the sealing state. See JIC fittings or visit any hydraulic workshop or agricultural engineer and they will put you right - they are quite common.

The same type of fitting is used on some carb heating systems where the engine oil is tapped off via a filter adaptor plate to circulate the hot oil through a "jacket" on the carb.

[Ian Law]

Many thanks Bill!

That all makes sense and I will do as you suggest.

Ian