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All ye take heart, the post from Eric on the Mercedes/Ate unit hold promise for us all. I think it confirms that indeed the sky is not falling. I believe I have analyzed things correctly below, let me know if I have overlooked something.

In the Hydrovac style power brake system, used by millions of cars and trucks in he US and in the Mercedes models here, a conventional single master cylinder without a residual check valve is acted upon by foot pressure. That pressure goes to essentialy what is a hydraulic amplifier.
Hydraulic in, assisted by vacuum acting ona a large pison, high pressure hydraulic out.

Note, if in the Mercedes or any other such equipped vehicle, the single master cylinder should fail there are no brakes at all. If Mercedes is confident to invest several years worth of research and design and then market this to vintage Mercedes owners worldwide they must know something. As a single master based system is good enuough for Mercedes,then it's good enough for me. Obviously Eric wouldn't have posted this link unless it was good enough for him.

Amen.

Fred Kanter
Kanter
Auto Products
Boonton, NL

The BTV has probably been the subject of a dozen or more threads that just go on forever. How about we give it a rest for a while? If some new information comes to light as the result of Fred's analysis, or otherwise, we're all ears, but in the meantime, we just keep recycling the same old stuff.

Newcomers have questions. That is one reason why the "same old stuff" seems to get recycled. They're new folks and don't realize how long the BTV discussions have raged on.

Post #28 above is a partial NOT completed list of topic headings covering the BTV.

I see no point in ending the discussions just because someone shows up recently with a promised future answer.

Post #28 above (of THIS thread) contains some but not all of the discussions for reference for newcommers or anyone to review.

Or to put it another way, i'm sure there are many (but not necessarily all) vendors and service providers of the BTV that would like to see the BTV discussions stop.

I vote to keep them open. NO ONE is forced to participate.

I'd like to think that new-comers would use the "search" function to see if their question has already been posed and discussed, in which case they'd find more than they could read in one sitting on this topic. But that doesn't seem to often be the case, so I reluctantly agree with you.

These scans from a Mercedes Benz Parts Book circa 1960 probably won't help the discussion much but they show the system used in the late 50's-early 60's era. This is an ATE unit.

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@ Clipper 47: Looks very much like the HydroVac on a 1964 GT Hawk I had. My car was disc equipped and had a remote reservoir on the firewall that fed the low mounted master cyl. Basically an updated carryover from the prior frame mounted master cyl system. Worked like a charm and I never heard of a failure among the Stude crowd.

I had the same system on my 65 Mercedes 230S finback model and it never caused me any grief either.

I don't recall any problems with the Hydrovac either. One difference -- at least in the Studebaker version -- it was conventional piston/cup hydraulics not the displacement ram.

I did find another ram type unit and that was used on "some" 53-4 Buick applications. Don't know who actually made it but it is labeled as Buick. Neither it nor the Moraine version of the BTV (also listed as used in various Buicks and other GM as well as BTVs) has the same compensator valve setup as the Bendix.

The fact that Buick/Moraine copied the basic ram principal but not the compensator valve might say something. Since GM seemed to mix these things up quite a bit using one unit part of a year, another the rest, and a different one the next makes me wonder if they had supply problems or operational problems.

iirc, the Moraine unit used in the 53 Buick got its own chapter in Nader's book "Unsafe at any speed". Anybody have a copy?

Of course anythings Nader dislikes tends to awaken warm and tender affection in me.

Two copies on eBay rite now for about $9ine.
http://cgi.ebay.com/Ralph-Nader-Unsafe-Any-Speed-1966-/230551623238?pt=US_Nonfiction_Book&hash=item35adf29646

Never thot i'd be referenceing that book let alone promoting a sale of it. But in view of GM's disgrace over the last 10 years it's too bad Nader doesn't make a strong comeback and fold them for good.