New T50 brake booster for Mercedes-Benz classics

Fellbach, Jun 26, 2006
  • New edition of booster brakes for Mercedes-Benz classics from the 1950s and early 1960s
  • Reproduction at the original manufacturer to original specifications with improved quality
Good news for all owners of Mercedes-Benz classics from the 1950s and early 1960s: as of now, the Mercedes-Benz Classic is offering new brake boosters – type ATE T50 and T50/12 – for historical Mercedes-Benz cars such as the 190 SL (W121), the 300 SL (W198), the 300 Sc (W188) and the Ponton models. In one of the most extensive reproduction campaigns, the Genuine Parts department of the Mercedes-Benz Classic Center cooperated closed with Continental Teves AG & Co. oHG in the reproduction of the brake boosters. “Complete brake boosters, individual parts and repair kits ceased to be available from the manufacturer years ago, which is why the reproduction run had become necessary,” says Stephan Bornert, Technical Product Manager for Genuine Mercedes-Benz Replacement Parts at the Mercedes-Benz Classic Center.
Consisting of 96 precision parts, the T50 brake booster is one of the most complex safety assemblies of historical Mercedes-Benz cars. Its function is to ensure that the pedal pressure exerted by the driver is raised in the hydraulic lines of the brake system so as to bring the car to a standstill quickly and reliably. However, not all owners of classic cars know that the brake booster ranks among the wear parts which are crucial for safety – and that it wears out gradually and almost imperceptibly. Few drivers realize that their brake boosters no longer decelerate their cars as effectively as possible. They have got used to a slowly but steadily rising pedal pressure, without noticing that stopping distances are becoming longer and clearly higher pressure is required for emergency braking maneuvers.
On the basis of experience gained, the Mercedes-Benz Classic Center proceeds from the assumption that some 80 percent of all brake boosters currently operating in classic cars from the 1950s and 1960s are worn. Even if replacement parts were still available – for instance one of the most important components, the so-called brake piston – replacement would not guarantee impeccable functioning and safety. The reason for this lies in the large number of different and precisely matched parts. In spite of this, this crucial part can be found in the form of hair-raising contraptions especially on classic car markets. The offer includes make-shift pistons, consisting of rubber discs which are bolted down between two sheet metal panels and even carry the A.T.E. logo, albeit in hand-writing. The question of the operational reliability of a brake booster with makeshift piston was answered in the very first test by the manufacturer: these would-be replacement parts did not survive the quality check.
This is why the Mercedes-Benz Classic Center decided to have the complete brake booster redesigned – rather than individual components reproduced. The decision was backed by the observation that a significant proportion of the brake booster housings and a large number of other components no longer meet safety requirements due to aging.
However, reproduction involved a lot more work and organizational effort than had originally been expected. When the reconstruction campaign was launched in 2003, it was clear that only the manufacturer of the original assembly had the competence to tackle reconstruction to original specifications. A major part of the design drawings had to be compiled anew to be able to pass on precise specifications to A.T.E.’s suppliers as well. The next difficulty on the road to reproduced T50 brake boosters came up in conjunction with the suppliers – some of the companies no longer exist today, while others are meanwhile engaged in the production of other engineering products.
It took two years to enlist the services of all the suppliers required, to compile all the design drawings and to complete all the preliminary tests. Each small part – each bolt and each spring – has to live up to Mercedes-Benz’s strict quality standards, after all. And each part has to prove its fatigue strength in arduous test series.
After the first brake boosters had been produced in late 2005, they were submitted to relentless endurance testing. On this occasion, it was established that the new brake boosters’ quality was even clearly superior to that of their historical counterparts. This is because many materials have been made much more durable in recent years – something that applies in particular to rubber seals. Today, they withstand much higher stresses and remain elastic and fully operational for much longer than their predecessors from the 1950s and 1960s. After some 150,000 braking maneuvers on the test rig, the newly built brake boosters virtually showed no signs of wear. These 150,000 load changes correspond to a distance of roughly 50,000 kilometers covered. There was no reason for complaint even after 300,000 simulated brake applications: all individual components met the requirements and could continue to be used without restrictions even after the endurance tests.
The Mercedes-Benz Classic Center offers the T50 brake booster in two versions for the model series set out below:
Designation: T50
Part no.: A 000 430 21 30
Model series: W105, W120, W121, W180*, W188, W198*, O319*
*depending on the Vehicle Identification No.

Designation: T50/12 Part no.: A 000 430 19 30Model series: W180*, W128, W198*, O319*
*depending on the Vehicle Identification No.

The price is the same for both brake booster versions, amounting to 2,500 euros plus VAT. Being a genuine Mercedes-Benz replacement part, each brake booster comes with a two-year warranty and is available at the Mercedes-Benz Classic Center or every Mercedes-Benz partner. Each brake booster is numbered and supplied with its own certificate confirming the pressure and function tests performed and passed by the unit.

DaimlerChrysler AG
Mercedes-Benz Classic Center
70546 Stuttgart
Tel.: +49 (0) 711-17 8 40 40


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    In the front: T50 brake booster, in the bachground: Mercedes-Benz 190 SL
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    T50 brake booster in a W 121
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    T 50 brake booster, view from the left
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    T 50 brake booster, view from the right
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    Sectional view, detail 1
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    Section view of the complete brake booster
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    Sectional view, detail 2
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    Graph of the brake booster