Re: 1954 Deluxe Clipper power brake to regular brake?

Posted by HH56 On 2015/10/8 12:37:39

The actual mechanical part of a rebuild is not difficult but you really need to be a stickler for detail and cleanliness in several parts of the system. Not recognizing potential issues at certain spots is most of the problem with home done rebuilds. If you are careful then there is no reason you could not do a rebuild. Many here have done their own.

Since the rebuild kit only contains primarily soft parts such as gaskets, seals and the rubber for the hydraulic section, the issue becomes the overall condition of the unit and recognizing when something is not up to standard. A scored part, corroded sealing surface, misguided earlier rebuilds and things like that make a huge impact that needs to corrected. Additionally, If there is a problem in the vacuum piston portion the rebuild kit does not offer anything. Any parts needed in that section has to be made or found NOS or installed by a rebuilder who has had parts re mfg'd but does not offer them for sale to others.

The BTV is a different animal compared to modern systems. On modern systems the fluid is contained ahead of a short stroke large diameter piston and is pushed to the wheels. While it is possible to have sudden issues with the piston sealing, it is less likely and there is usually a soft feel or warning something needs checking.

On a BTV the fluid is contained in an enclosed space and is displaced to the wheels by action of a long stroke ram taking up space that is filled with fluid. The ram never touches the cylinder walls and the fluid having nowhere to go is forced out to the wheels. Unfortunately, that fluid has to be contained in the enclosed space so all the pressure is taken by a blob of rubber called the compensator valve or by the ram seal itself. The compensator valve is usually where most problems occur. It has to seal absolutely but a bit of floating debris such as congealed or crystallized fluid can lodge on its surface or a weak spring doesn't lift and tilt it to close and you instantly create a no seal condition. The ram seal can be compromised by a score on the ram or corroded edge of the bore. Aside from that, there are also conditions in other seals or parts that can allow the fluid to be sucked into the vacuum side with the resulting loss of brakes.

Properly rebuilt they are reliable and many other car mfgs used them for several years. Knowing when something is wrong or marginal in those critical areas comes by experience. A failure anywhere in the hydraulic side is usually without warning and is a complete brake loss. The expertise part in knowing where and what to look for is the main reason for recommending the units be done by a competent rebuilder. Stop at one corner and not the next is a sad motto several on the forum have come to appreciate.