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I guess I used the wrong word in "picture". Don't think it was so much photos as to try and get an overall view of what if anything seemed to be a common failure mode in the actual unit. To that end he had offered to pay shipping cost for any old failed units back to Kanter's warehouse so it could be evaluated.

The details are in one of the many many BTV threads but unless someone can remember which one to point the way, not much help. I don't know if the offer is still good.

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Not in my experience.

My dad worked as mechanic in a Packard dealership for the better part of ten years and purchased a brand-new Exec in the spring of 56. He put nearly 75K on that car and traded it in on a new 63 BelAir. Driving all those miles/years, up/down the hills/valleys and winding mountain back roads in this area, with a few trips back-n-forth to Chicago thrown in for good measure, he NEVER once had a problem with the BTV in the Packard.

In the first Patrician that I purchased, with 66K on the clock, back in 1987, I experienced nothing more than a loss of power assist with the BTV. That was only because someone had previously replaced the original, formed, internal vacuum hose with a piece of cheap fuel hose, which wouldn't stay on the fitting.

In 1989, I rescued a rusty, but running 55 Patrician. The odometer read 58K, but the car looked more like 158K. I've no idea of prior service history, but the BTV never went out while I was behind the wheel. I never made much progress with that car before I sold it in 1993, and I only ever had it out on the road a few times - a few miles, back and forth, from offsite storage.

I purchased a second 56 Patrician in 1990 - rescued from a garage where it had been sitting for 23 years, with just over 60K on the clock. I had to overhaul the entire brake system - even the wheel cylinders were seized from sitting so long. I carefully disassembled, cleaned, and inspected the vacuum section and reassembled it without a single new part - not even the leather seal. Everything looked to be OE inside the BTV, but I used a kit from Kanter for the hydraulic section. I filled the system in this one car with DOT5, and never had a problem with the brakes since, but - again - only drove around the lot of the dealership where I worked all summer on it and back and forth from offside storage.

That's because I picked up a Carib Hardtop in 1992, with just over 66K on the clock, that had come here from AZ. The PO had purchased it as a used car, back in the late 50s, and drove it regularly for several years and then recreationally until 1977. He didn't mention any problem with the BTV - just routine replacement of shoes and a couple of leaky wheel cylinders. All I've done to the brakes was adjust them and top off the reservoir.

I've had a few other BTVs apart - some for rebuild, some for parts. Seems like corrosion is a problem in tired, old units that have been unused/unmaintained for many years - especially those that have been left outdoors in wet climates. All seem to show some evidence of a little fluid in the very bottom of the vacuum shell, but I suspect that's mainly from the relief port.

However, I find it odd that complaints of sudden failures BTV seem to have only come up in the last decade or so. I suspect those units suffer from substandard reproduction parts and/or incompetent rebuilds.

Brian, that's good info to hear on your experiences with the BTVs. I'm slowly getting used to the idea of trying my BTV again. I can always go back to the modern booster-m/c-pedalmod if I must.

bhappy Quote:

Just to clarify my experience with rebuilt BTV failures:

1) Came with my 55 Pat when I bought it. In traffic, the pedal slowly went to the floor until bottomed, then no brakes.

2) Came from a professional rebuilder in CA; installed professionally. Failed slowly going to the floor.

3) Came from Whitepost Restorations after rebuild including sleeving the vacuum can and MC. It failed completely and with no notice in slow traffic.

4) Rebuilt by a professional restorer in Las Vegas. Failed same as 1), but then partially came back after pumping vigoriously. Replaced it with custom MPB and releveraged pedal.

Each failure was about 1 year apart and somewhere between 5,000 - 10,000 miles of daily driver and long distance trips.

During this time, I talked to many 55-56 Packard owners about my problems with the BTV. At least 6 stated that they had also experienced a sudden BTV failure.

So, as to the question of how frequently does the BTV fail? See above. How many failures does it take to convince you that you are risking your life and limb everytime you step on the brake?

If your 55-56 Packard is a trailer queen or rarely driven, you may be OK. If you actually drive it a lot like I do, then you'd better replace the BTV with something else.

Craig

By all accounts I can find TreadleVacs were not trouble-prone in their day, if they were they wouldn't have found continued useage in all or most all brands of Ford and General Motors and most of the independents and lasted up into the early 60s, at least in Mercedes-Benz. Just why some folks have experienced problems and others have not has been a lively topic on this forum for nearly as long as it has existed. I've owned two cars with TreadleVacs, driven them tens and tens of thousands of miles, and never experienced a problem nor have most of my friends with BTV-equipped cars. We'd all like to know why we have this large of range of experiences. Certainly from the post-mortems that Fred Kanter did we know some of the causes though I don't think he ever received enough examples to find the complete range of failure mode. Those I recall dealt with improper assembly, substandard (50 year old?) rebuild kits, use of marginal parts like pistons when new ones were available, etc. Yet I suspect there is still something else out there we haven't yet found.

If you have more interest in Fred's findings, why not give him a call.

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i wonder if local climate could play a role, specifically humidity, what with leather seals,etc. I live in CO which is very low humidity (high desert). Craig is is in Nevada (also a low humidity environment). O_D is on the east coast and I'm assuming most of his cars were located in fairly humid environments. My car came from Rockford, Il and came to CO in June of 2010. The BTV failed in September of that year (about 3-4 months). The previous owner of my car in Il had no problems with the BTV and was shocked when he found out about my BTV woes.

One thing that has been interesting is the great majority of our complaints seem to be in V8's. Since Packard units are located in exactly the same place, the only difference is an exhaust manifold. It would be interesting to know how many of the other mfgs also have the units fairly close to heat.

V8's and BTV's:

What percentage of PAckard products 54 and earlier had Power brakes vs percentage of 55's and 56's with power brakes????

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Hmmm...High heat and Low Humiidity. I wonder what might become of that?

EDIT: I mentioned that my experience is in space, satellites to be exact. This BTV problem makes me think of the Challenger's O-ring failure. Satellites are built to withstand high temperature deltas (absolute zero to hundreds of degrees).

Quote from BH post #22 above:

"My dad worked as mechanic in a Packard dealership... purchased a brand-new Exec in the spring of 56. He put nearly 75K on that car and traded it in on a new 63 BelAir. ... he NEVER once had a problem with the BTV in the Packard.

However, I find it odd that complaints of sudden failures BTV seem to have only come up in the last decade or so. I suspect those units suffer from substandard reproduction parts and/or incompetent rebuilds."

BH's last statement deserves much consideration in any analysis of the BTV. Since noone has been keeping track or record of BTV failures along with service providers used and/or source of parts then there is no way to determine exactly what is nor who is substandard and/or incompetent rebuilders. It was only about a year ago that we learned from one of the big name vendors that there are at least 3hree different compensator valves availabe from various UNNAMED sources.

Now consider BH's first sentence from above. ca late 50's time frame 7 years and 75K miles with no problems. Makes one wonder if his father drained and flushed the entire brake system every 1 to 3 years or had it rebuilt every 3 to 5 years whether it needed it or not.