Hydrovac
Hydrovac is the name of a patented pneumatic brake booster from the American company Bendix Aviation Corp.
distribution
The Hydrovac was used in the 1940s to 1960s e.g. B. Used in the following American, French and German cars and trucks: Ford Truck, GMC Truck, Chevrolet Truck, Studebaker , Clark forklifts; Peugeot 404 , Renault Alpine ; Mercedes-Benz 190 SL , Unimog 411 , BMW 502 . These were vehicles that, due to their weight or performance, for. B. with duo-duplex drum brakes (referred to as thermostable at Peugeot ) or were already equipped with disc brakes. The license holder had been Alfred Teves GmbH with the Ate T50 brake booster since 1951 . In the 1960s, the Hydrovac was replaced by the Mastervac , also a patent from the Bendix company, built by Teves as the Ate T51 from 1961
You can also read about the use of the Hydrovac in various forums.
Working principle
The Hydrovac brake booster consists of three parts:
(A) Pneumatic cylinder (brake booster)
(B) Hydraulic cylinder (master cylinder)
(C) Hydro- pneumatic control unit
On the piston of the master cylinder (B) functions unchanged for the pressure of the master cylinder . However, the piston rod of the pneumatic cylinder (A) introduces an additional force that is generated by the difference between the ambient air pressure and a certain negative pressure. In vehicles with a throttle valve, this negative pressure is tapped below the throttle valve, while diesel vehicles have a vacuum pump. The control unit (C) adjusts this force depending on the brake pedal position.
(Note: There is currently no copyright-free sectional view to explain the text.)
The Hydrovac type brake booster is also characterized by the fact that it can be retrofitted because it is inserted in series in the hydraulic line behind the master brake cylinder.
Designs
The early Hydrovac devices have a cylindrical housing with tie rods and a sliding sealing sleeve for the pneumatic piston, which was initially made of leather and later of rubber (type 1). Later Hydrovac devices instead have a rubber bellows, which is clamped between the two halves of the housing and does not drag, but rolls off. The housing halves are either screwed together like a jam jar (type 2) or closed with a clamp like a barrel (type 3). For particularly high forces, where the housing diameter would be too large, there are also tandem versions (types 4, 5).
Spare parts supply
The American designs are all available as replacement parts. The Ate T50 devices for Mercedes-Benz are sold exclusively as new parts through the Mercedes-Benz Classic Center . A spare parts dealer specializing in French vehicles is offering new Hydrovac devices in various sizes from a Spanish manufacturer. Information about the possibility of overhauling a Hydrovac is available from repairers who specialize in classic car brakes.
Individual evidence
- ↑ a b ATE Classic - Advances in brake actuation from 1951 to the present day. Continental AG Automotive division, archived from the original on March 13, 2013 ; Retrieved October 30, 2011 .
- ↑ stovebolt.com forum. Retrieved October 30, 2011 (English, US forum on pre-1973 Chevrolet and GMC trucks ).
- ↑ Technique Peugeot 404. Retrieved on October 30, 2011 (French, French blog on Peugeot 404 technology topics ).
- ^ A1 Cardone . Website of Cardone Ind. Inc., division Remanufactured Parts. Retrieved October 30, 2011.
- ↑ Mercedes-Benz Classic website of Daimler AG. Retrieved October 30, 2011.
- ↑ Der Franzose website from Der Franzose. Retrieved May 8, 2012.