Packard Forum Index » V-8 (1955-56)

Craig, Eric,

OK, you need the extra leverage the relocation gives you to make the foot pressure acceptable. Is there no room on the other side of the firewall to use spacers on the MPB mounting bolts? Looks like the frame rail is too close. Also, why do you have to cut the brake pedal? In its new location does it interfere with moving the right foot from the accelerator to the brake? I'm a right foot braker and don't want to change.

I tried to change for a while when I had surgery on my right foot and it was a harrowing experience. Using my right foot to brake has become ingrained and I found I had to think about which foot to use. In an emergency I don't want to have to think about which foot to use.

Quote:
<p>It's not foot pressure, it is hydraulic line pressure. Without the 3:1 leverage, the brakes will not actuate sufficiently, i.e., it acts like there are NO brakes!</p>
Quote:<p>YES!</p> When you install it, it will be patently obvious.</p> <p>I have a used 1956 Pedal assembly I can sell you if you want to save yours. PM me if interested.</p>
<p>Craig</p>

Craig,
Thanks for the info. I printed the pictures from your Panther website and then walked out to my car for a look. Now it's obvious to me why the ratio is 1:1 and why you cut the brake pedal. I may take you up on the offer for the used brake pedal.

I also saw Joe Douglas' post where he had talked to Fred Rupert at MPB. I may give MPB a call and ask exactly what they offered Joe. If they can make a bolt in replacement with the same pedal ratio then I shouldn't have to modify my brake pedal. I'm not sure how they would do that though. I'll guess I'll have to wait until Monday to ask.

If you do talk with them, how about asking if they offer a bolt in replacement for the BTV like this one for a 55-7 Chevy from ABS. Am curious how it would compare with the real thing size wise, length wise & pressure wise with the dual 7" booster and 1" cylinder. With a remote fill cylinder, would it work in this situation. If not too much longer or wider, the toe board & pedal could probably be reworked slightly to accommodate but since the Chevys had it mounted higher, if it would still need a ratio change, then maybe not workable.

Attach file:

---

  (40.24 KB)

HH56,
This looks interesting. Have you talked to ABS to see if they have a replacement for the BTV in Packards? I'll ask about a 55-7 Chevy drop in when I call MPB.

I have not, but doubt there is otherwise it would surely have been mentioned by someone already.

Several sites sell the Chevy kit but as mentioned, it is mounted higher up and level on a Chevy where length and width not an issue. We would need a remote fill for the angle and location under steering column. No idea where/how the BTV was mounted on other cars that used it.

Biggest question would be since the BTV has a single approx 6" power cylinder and this is dual 7, would that be enough to overcome the 1:1. As Craig mentioned, his single 7 was not. There would also be another pressure difference and volume tradeoff in the fluid portion as the BTV has a narrow long stroke "piston" that displaces or squeezes fluid out vs the shorter 1" cylinder on the replacement which pushes.

The volume & pressure loss still may be enough to kill the possibility even with larger booster. I noted Jerry went to a larger cylinder from what he originally drew. My guess would be maybe a narrow cylinder, even though it would provide higher pressure, must have volume limitations.

If this wouldn't work, then the only other option I can see that may work & be small enough to keep things in the same place and geometry would be to use something like the ABS electro boost. That is small, requires minimal plumbing changes & components can be hidden. Pressure output is adjustable to way over what we need so should compensate for the 1:1.. It's also pricy & 12v only.

For those with FACTORY AC.

USe the Set up like Craig has with STANDARD pedal ratio and stock pedal. BUT, let Craigs unit push a slave that in turn operates a standard off the shelf powerunit and Master cylinder that is remotely mounted. Maybe in the trunk.

Someone had a similar set up displayed here at this forum or maybe over at the AACA forum some 4 or 5 years ago.

...

I wonder what Packard34 found to be the cause of his brake failure????
Any fluid found in the vacuum part of the BTV????

Can you supply the telephone #s and full names of the two brake companies ABS and MPB?
I would like to upgrade to a dual master cylinder for our 1955 Constellation.
Hate to have to ask as all of you already know what the abbreviations stand for.
On the other hand this is the best web sight for Packard info. and has helped me "a first time Packard owner" with the restoration of our car.
Thank you
John