Restoration-Mini

Technical Forums => Maintenance and Modifications => Topic started by: tmsmini on December 01, 2022, 09:04:02 AM

Title: Late Model(post 88) Brake Servo
Post by: tmsmini on December 01, 2022, 09:04:02 AM
Any one have a link to rebuild directions for the latest style servo?
Or hints and suggestions?

There are more parts supplied than I was expecting:
http://minispares.com/product/Classic/Brakes/Servos/GSM120.aspx

In the past I have just carefully documented everything with the direction of the seals for master cylinders, but there are diagrams to check against.
I have not found a diagram for this servo.
Title: Re: Late Model(post 88) Brake Servo
Post by: MiniDave on December 01, 2022, 09:31:08 AM
Are you talking about rebuilding the servo itself, or both it and the master?

Aren't complete new servos about $200?

The servo itself is pretty easy, just two halves of the can that twist apart and a big rubber diaphragm inside. Use plenty of rubber grease putting it back together.....it looks like the kit you linked has a sachet of rubber grease in it.

The master cylinder shouldn't be any big deal either, if you've done one, you've done this one.

I did the one on my Jag years ago and I don't remember it being any big deal, but the one on the Inno was badly corroded so I bought a new one. I think the hardest part will be separating the two halves of the can. It's been a long time but I think all I did was use a bar across the MC studs with the other end clamped in my vise to hold it.
Title: Re: Late Model(post 88) Brake Servo
Post by: BruceK on December 01, 2022, 10:03:25 AM
I replaced that type of servo on my car about 5 years ago after the check valve and/or bladder failed and the carb sucked in a lot of brake fluid.  Decided to spring for the entirely new servo (figured it was only about $100 more than a rebuild kit) for piece of mind and simplicity. 
Title: Re: Late Model(post 88) Brake Servo
Post by: tmsmini on December 01, 2022, 06:01:48 PM
Looks like it is still only $100 more than the rebuild kit. I was expecting the rubber diaphragm, but there is a plunger with seals as well.
I bought a new master cylinder, should have gone for the servo as well.