[Healeys] Help-Low pressure in the overdrive unit

[WILLIAM B LAWRENCE]

You may need to replace the o-rings on the accumulator piston housing. When 
these deteriorate and start to leak by the accumlator won't build enough 
pressure to operate the OD.

>From: Maurice Maxwell <maxandreb1 at yahoo.com>
>To: Healeys at autox.team.net
>Subject: [Healeys]  Help-Low pressure in the overdrive unit
>Date: Mon, 21 Jan 2008 13:11:12 -0800 (PST)
>
>My overdrive unit will not engage and has an operating
>pressure of about 320 pounds pressure at 1000 rpm on
>the tach.  Removal of the accumulator spring and
>placing two washers as a ship under the spring
>increased the pressure to about 380 lb pressure at
>1000 rpm and about 400 lb at 1500 rpm.  There was no
>trash on either operating valve ball or the pump
>non-return valve.  The oil appeared clean and there
>was no trash in the filter screen.  What could be the
>most likely cause of the low pressure?
>
>Thanks in advance,
>Max
>1961 BT7