A few months ago, a list member complained that the hydraulic fluid in
his clutch master cylinder had turned murky shortly after rebuilding the
master and slave cylinders, and asked if anyone knew the cause. Most
respondents said that their fluid stayed clear, and suspected some
incompatibility between the rubber seals and the fluid. A couple of
people responded that they had the same problem, even though they were
using Girling parts and Castrol LMA DOT 4 fluid.
When I rebuilt the master and slave cylinders on my son's Spitfire
almost two years ago, I had the same problem. We even flushed the system
to get fresh LMA all through the system, but within an hour, a greyish/
purplish sediment was already starting to enter the master cylinder's
This week, the master has started to leak, and I've ordered another
rebuild kit. I used the official Girling kit last time, but I suspect
that the seals were deteriorating from the start.
Has anyone else had this problem, or can recommend a couple of does and
don'ts during the rebuild?