Packard Forum Index » Post-War (1946-54)

walkerman.
WHen u get a free momment tip the BTV to it's side to see if any brake fluid comes out of the tube that the vacuum hose attaches to and note the estimated amount of fluid.

Also, check the BTV fluid reservoir to see how low (if any) it is asuming that not much fluid was lost after it was removed from the car.

If the master cylinder portion of the BTV unit is disassembled watch closely for any bebris that mite be preset.

Side note: We do not live in a perfect world. Debris can be present in ANY brake system. But the BTV compensator port is much more vulnerable to debris than more conventional master cylinders designs.

I'd be curious about fluid in vacuum chamber also but don't think you will be able to check it unless you remove the front cover and power piston. Unless a huge amount, don't think it will be able to pass the piston to get to the vacuum hose. Would also be curious what type gasket you have on the reservoir cover--whether the relief port is blocked by the replacement gaskets as we have been finding.

With the symptoms though, would more suspect the compensator valve --debris a possibility but sure developed quickly if there is any or perhaps you got one of those poorly made valves that another poster mentioned on another thread.

PackardV8 wrote Quote:

Keith, I know you have replaced your BTV with a modern dual master MC with booster on your 56 Exec, so I'm somewhat perplexed as to why you are interested in the exact failure mode of the BTV. Maybe you should have been a medical coroner.

Maybe you are correct about the debris issue and the BTV being more vulnerable to failure than other designs. If so, there's no getting around that in the real world.

In any case and for whatever reason for BTV failure, if there's a reasonable solution which entails replacement (of which there are several), it is inconceivable to me that one would retain the BTV when the consequences of doing so are potentially so dire.

Craig

Fred Kanter wants to take apart and inspect.He can give report.

Fred Kanter wants to take apart and inspect

Glad to hear you made it available. Now if a few other recent failures could be offered as well, maybe something common could be found.

Looking forward to Fred Kanters findings.