At 08:12 PM 5/9/99 EDT, Bruce Larson wrote:
>
>I have appreciated the help in the past and have yet another question due to
>my limited knowledge of mechanical matters. I am trying to rebuild the
brake
>master cylinder in my 1967 Spitfire Mk III. It is the single circuit type.
>For the life of me, I cannot figure out how to remove the piston. I have a
>Haynes repair manual and have followed its instructions on removing the
>master cylinder from the car and extracting the circlip to remove the
>pushrod, but I am unable to determine how and where to remove the "spring
>thimble". As always, thanks for any advice.
Bruce,
The "spring & thimble" are located behind the piston in the bore of the MC.
Your problem is not uncommon. Quite often, dirt and gunk, gum up the bore
of the MC and the piston will NOT fall out. If you have a compressor handy,
run the regulator down to 5# or so. Wear some leather gloves, and with the
gloved hand, cover forward most port with your finger/thumb. With a blow
down attachment on the end of the compressor's air hose, press the blow down
gun into the other port. You should have the MC facing something like a
block of wood to limit the projectile motion of the piston. Now release
some air into the MC. This will usually BLOW the piston out of the bore.
BECAREFULL AND DON'T USE A LOT OF PRESSURE as it will shot the piston out
of the bore and it will bounce off the walls, if it doesn't bury itself in
the wall. You don't want to damage the piston.
Once the piston is out of the bore, the spring and thimble will come with it.
The thimble is usually held to the piston via a metal rod with a balled end.
You release this by pressing down on the spring and sliding the balled end
into the larger end of the slot it is in.
You might want to check out my article on "Rebuilding Brakes" on my Morgan
web page (listed below) under the restoration articles section.
John
John T. Blair WA4OHZ email: jblair@exis.net
Va. Beach, Va Phone: (757) 495-8229
48 TR1800 65 Morgan 4/4 Series V (B1109)
71 Saab Sonett III (71500840) 75 Bricklin SV1 (0887) 77 Spitfire
Morgan: www.team.net/www/morgan
Bricklin: webus80.wang.com/BI (new adderss)
|