Packard Forum Index » V-8 (1955-56)

Some GM cars (Cad, Chevy, Buick maybe) and I believe some Mercedes models did use the Bendix Treadlevac (BTV for short). The other mfgs did for the most part mount theirs differently than Packard so as to have a better pedal ratio. Eventually GM licensed rights to more or less copy the BTV and produced their version as a Moraine unit. The two operate similarly but as I understand it the Moraine version had some issues, one big one being that if a seal failed, the way ports and seals were positioned vacuum could easily suck all the fluid out of the master rather quickly.

From reports of small amounts of fluid found in the vacuum side of the Packard version, their BTVs apparently had that issue to some extent but not like the Moraine. Many of the Packard issues can be traced to a gasket and the flat reservoir cover Packard used which was OK on the first version BTVs but the same cover carried over to the later versions and blocked off a relief port on those. That blocked port caused any hydraulic seal leak to force fluid into the vacuum side or a vacuum seal leak to pull fluid rather than have an open path into the reservoir area so it could move fluid back or pull air instead of fluid. That has been noted and corrected on rebuilt units by most of our Packard vendors but unknown how widespread it might be in other rebuilds.

I do not know which GM models used Bendix and which Moraine but the unit you picture is a bit different from what Packard used. I can't say if it is the BTV or the Moraine. The vacuum input is different as is the reservoir cover and vent and there appears to be a bleed screw on the master that is not present on the BTV. If it is a BTV that one might work although there would be two check valves in the vacuum line which could cause a conflict. You might compare price with Max or Kanter for an authentic Packard rebuilt or ensure what you get from somewhere else is at least a second version poppet valve type Bendix unit as Packard used from 53-6.

The units differ quite a bit between makes so best to stick with the one made for your car. I am personally not keen on disk brake conversions as the drum brakes were well-engineered and work well when kept in good condition. It seems a big risk adding disks to the existing master which was never designed for it.

That said, the valve in question is easy to remove and simply lifts out after you remove the brass fitting at the front of the master cylinder along with the insert behind it. You should be able to do it in the car without removing the unit.

Also, I bought one of the reproduction castings that you showed but it is missing a hole that will have to be added for proper operation.

Unless you're planning on a routine of very agressive rallye-type driving, the original drum brakes, properly maintained, are quite adequate for normal driving circumstances.

Thank you for responses Howard, Owen and Don. Pedal ratio and swing mount pedals will probably be another issue with this. Stay tuned.

TC

Hi Howard. Just following up on this from August. Regarding the yellow arrow, is this the residual pressure check valve? Regards, TC

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Good morning Howard, do you by chance have a diagram or dimensions/blueprint/specs of a 359 L8 radiator? I would like to be able to submit to a custom fabricator to be able to drop in a new modern max cooling radiator. Regards, tc

I do not have any plans or drawings for the radiators but there is a possibility the blueprints might be available from the Packard Motor Car Foundation. I believe Bruce Blevins is still the person in charge of caring for them but if not, someone will surely know who is current and how to reach them. You would need to supply the part number for the radiator you are looking for and have him see if it is one of those available for copy and sale.

The only other info I can provide is Packard specs in the April, 1954 Vol 28 #4 Service Counselor has the flow rate for the senior 359 radiator at 31.25 GPM.

For blueprints, try Andrew Beckman who is the archivist at the Studebaker Museum. So far they've had most anything I have needed.

I'm on it. Thank you as always!

Regards,

TC

Thank you Don !

Regards,

TC