[Amel Yacht Owners] Shaft Brake-ATF Leak

sailormon <kimberlite@...>

Hi Drew,

I sent you a drawing of the shaft brake cylinder. You have an O ring that needs to be replaced.

It is a very simple job.

Fair Winds


Kimberlite Amel Super Maramu #376



From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, August 11, 2018 6:06 PM
To: amelyachtowners@...
Subject: [Amel Yacht Owners] Shaft Brake-ATF Leak






Recently noticed Automatic Transmission Fluid under and on the aft end of the shaft brake after motoring.  The fluid seems to be coming from the around the adjustment bolt on the brake.  I've tightened the 4 hex bolts on the aft end-cap of the brake cylinder, but it still leaks.  The fluid collects on the support rail that holds the brake.  The transmission filter cover, seal with the engine, etc.are dry.  I recently cleaned the ATF heat exchanger and the transmission runs "cool".

It looks like there are seals in the brake cylinder.  I've not opened it.

Has anyone had this problem?  Any suggestions?


Drew Gaffney
SV Revelation SM390
Lying Marine Sifredi, Carloforte, Sardinia

Drew Gaffney

Thank you Eric and Bill.
Will service the brake cylinder on return to Revelation later next month.  
Additional question:  Is there a need to bleed the system?  I noticed that there's a large "set screw" on the forward end of the brake cylinder.  I've had to disconnect the hydraulic line several times and haven't done any bleeding, but disassembly will likely empty the fluid from the cylinder.
SV Revelation SM2K #390
Carloforte, Sardinia

Alan Leslie

When the engine is stopped and the spring whose compression you adjust with that bolt on the end has pushed the piston all the way such that the brake pads are gripping the disc, there's very little fluid in the cylinder. 
I've taken it all apart and put it back together without bleeding it and it seems fine. 
Considering that the only way to bleed it would be when the engine is running and the gearbox is delivering pressure down the hose to the brake cylinder (which is what keeps the brake pads off the disc) I'm not that keen to attempt it !
Elyse SM437
Port Havannah, Vanuatu