Moss Recall of Master Cylinders

Notification of A Voluntary Recall of Brake Master Cylinders

This voluntary recall applies ONLY to the brake master cylinders listed below:
Item
Description & Application 180-791
   
Brake Master Cylinder for Nash Metropolitan
Clutch Master Cylinder for MGA Twin Cam and MGA MK II Deluxe

513-319
Brake Master Cylinder for Austin Healey BN7, BT7, BJ7 (Cars without a brake servo)
Clutch Master Cylinder for Austin Healey BN4 from CE 48863, BN6, BN7, BT7, BJ7, BJ8 without a brake servo

581-101
Austin Healey 3000s (BN7, BT7, BJ7, BJ8) with power brakes.

581-011
Triumph TR3 from TS13046 through TR 3B

581-032
Triumph TR4 from CT5784 on and TR4A. (Girling brake system)

581-512
Brake Master Cylinder on Austin Healey BN4 to CE 48862.
Clutch Master Cylinder on Triumph TR4-4A.
The Moss Technical Services department has determined that between approximately March 1, 2010 and February 1, 2011, we received, and sold brake master cylinders from a single manufacturer under the brand name Classic Gold (with one exception) with an internal design element that may fail in use. Specifically at issue is the foot valve. Although no one had reported a foot valve failure in an installed master cylinder, it had been suggested that because the foot valve design differed from an original Girling design, it was suspect. There are many different foot valve designs, so the difference in appearance or design is not, in and of itself, a cause for concern. However, the manufacturer of the master cylinder did not have test data on this particular valve. We suspended sales and arranged for the brake master cylinders to be tested according to SAE standards by an independent automotive testing laboratory to determine if there was a risk of foot valve failure in use.

Foot valve failures were experienced during the extreme pressure test at 3,000 psi and after 10,000 cycles at 248º F during a heat durability test. The pressures and temperatures used in the tests far exceed the pressure and temperatures you would experience with the master cylinder installed in a car, but the failure of a foot valve is serious because it closes off the port to the brake fluid reservoir when you step on the brake pedal. If the foot valve fails to close, the pedal will go to the floor without putting any pressure on the brake shoes or pads. In other words,

Your brakes could fail, with the potential for serious injury.

Moss is therefore voluntarily recalling the brake master cylinders listed above because they share this particular foot valve design.

Sincerely,

Michael Grant
Product Manager, Moss Motors Ltd