Brake bleed nipples and union screws

[dudload]

Evening all!

I've recently received all the new bits for a front brake overhaul given seized and leaking cylinders.

However, I'm a little concerned that the union and bleed nipples don't properly seat. Photo attached, but this is as far as they go in without undue force (I know the nipple isn't accidentally the larger threaded rear nipple as also have them)

Is this supposed to be how they're connected, or is it a contact esm job?

20240409_172655.jpg (1.99 MiB) Viewed 326 times

[ManyMinors]

What makes you think they don't seat properly? The seating surfaces are out of sight inside the wheel cylinder aren't they.
Whenever I have changed such items and bled the brakes I've always got somebody else to push the brake pedal hard while I check for any leaks at joints etc. Just tighten them up and don't worry about the exposed thread, then check for leaks afterwards. All should be well

[dudload]

Thanks - I can feel they're seated right inside, but just nervous about the full thread not being in and nut flush to the body. If not a worry / this is normal then all good.

Blake bleeding shenanigans here i come!

[simmitc]

Have a look at the old ones. You will probably see a similar length of exposed thread which should give you confidence.

[dudload]

the old bleed nipples are a little less exposed than that, but the union joints were flush, which is what gave me the jitters

[jaekl]

The front wheel cylinders have different types of flares than the other connections. It doesn't hurt to compare the shape of the flares to see that they are compatible.

[geoberni]

Unlike you I would be most concerned if the connections were flush.

How can you be certain they have correctly screwed down if they are flush?

I had a 37 year career in aircraft engineering and I would never expect to see a flush pipe Union in the way you speak of....
I can't think of any brakes I've done in recent years where the connector went flush; I fitted new front Disc Callipers to my Kuga a few weeks ago and they are a few threads showing too.

[olonas]

wheel cylinder.jpg (226.96 KiB) Viewed 177 times

For a comparison here is a new front brake cylinder with a new bleed nipple, fully screwed in, and a "transfer pipe" seated.

[dudload]

thanks again all - reassembly happening tomorrow due to weather. will let you know how it goes - mind fully at rest on threads now

[dudload]

all back up and running now - took forever to bleed with a spongy pedal. Eventually got a fairly spongy pedal, but still with the ability to brake hard and took it out on a run around central london, at the end of the fairly long drive pedal was strangely alot firmer and could lock the wheels at 20mph.

will give it another bleed over the weekend as i can only assume that the new shoes needed bedding in and going over the infinite speedbumps shook air out of the wrong places (hopefully sitting nicely under the bleed nipple waiting to be removed)