I know this has been discussed before, but I remain puzzled. The 15-year
rebuild of my Mk 1 Sprite is finished, except that the master cylinder has
gone rusty - again! First of all I honed out the brake and clutch bores,
assembled the unit, wrapped it up and stored it away in the house. When I
assemble the system I found the bores had rusted in storage. So I honed it
again. By this time I was nearly ready to roll so I reassembled and bled the
system, which worked OK. Then there was a delay with the clutch, so the car
didn't move for about a month, by which time the bores had rusted yet again.
It's now beyond honing so I am having the bores sleeved with stainless
steel - which of course I should have tried before. This is a very difficult
job as there is so little material between the bores, but my engineer says
it's in progress. It will cost nearly as much as a new unit, but won't go
rusty again.

Having had a discussion on this NG and elsewhere about brake fluids, I am
using DOT 4 not silicone, so I'm well aware of the hygroscopy problem. But
why is this not a problem with other vehicles? My motorhome sits idle for
months on end and the brakes are always perfect. Why is the Sprite plagued
with this? This is not new - I was honing master cylinders 20 years ago. Why
are the cylinders not chrome plated? This would solve the problem cheaply.

"Asolepius" <lesrose***@ntlworld***.com> wrote

perfectly. Now a thought occurs to me. Would anyone else like a sleeved
cylinder on exchange? I think it could be done for a bit less than a new bog
standard one, now that the methodology is worked out. Email me if
interested.