Tokico BM50 Brake master Leaking

[brill]

I have just rebuilt my Tokico BM50 Brake master which fitted in the car fine, but while bleeding the brakes struggled to get a decent pedal.

I put at least 2 litres through the system and had previously bench bled the BM50, after many rounds of bleeding in the traditional sequence with the ABS disconnected, and battery earth disconnected the pedal travel was still way to long and still felt spongy, so i checked all round the car at the calipers, the two brake line connections to the master which were all bone dry, it was only when looking round the engine bay with a torch that i noticed a slight weep of fluid from the small hole between the two Hardline connections on the Brake master, when my friend had hard pressure on the brake pedal.

Can anyone tell me what this small hole in the BMC is designed to do and what might have failed to cause the small leak, I have tried looking on line and can not find an answer to what this hole does.

I will include a photo of the cylinder with the hole highlighted, any help would be appreciated

https://www.youtube.com/@Marc-my4sw

 

[Actual_Ben_Taylor]

Any help?

https://www.sau.com.au/forums/topic/428274-master-brake-clynder-leaking-pic-included/

Seems to imply it could be to do with the proportioning valve

 

[brill]

Thanks for the link,

I have had a look and yes it does seem to point that way, but it is mentioned in that thread that its a small hex in that hole and there is no hex at all in mine, there is another link in that thread to a post in "Skyline owners" web site but the post is not found.

I assume it must be a curable issue as the guy that started the thread you put me onto had his rebuilt and it was fine after that, However what the actual issue is seems hard to pin point.

Thanks again for the link I will keep looking