<VV> Dual MC conversion failures- brake experts?

[Bryan Blackwell]

On Mar 11, 2011, at 12:02 PM, Bob Gilbert wrote:

> Is there a final "word" on this topic? In the case of the UltraVan, this
> isn't a trivial job so I just want to make sure I will really have the peace
> of mind that I thought I would be getting with the conversion. 

Hi folks,

I thought we had a pretty definitive answer from the thread a month or so ago.  Here's what I understand from the info from Larry Claypool:

 - The switch block on the stock dual m/c is only a switch, *not* a shuttle valve.
 - Activating the fail safe is based on having enough travel of the m/c pushrod.

So, the key to the install is having enough travel and proper adjustment of the pushrod.  If you run out of travel before the empty chamber in the master cylinder closes, you still won't have brakes.

The only unresolved question I recall is if there was a difference in the brake pedal lever on later Corvairs to give more travel (at the expense of less leverage).  It should be a fairly simple matter to drill another hole if more travel is required.

I intend to check mine when I flush the systems next, likely starting with the '66 since it's been a few years now.

--Bryan


Bryan Blackwell bryan at skiblack.com
http://autoxer.skiblack.com/
  Corvairs: '62 700 Wagon, '64 Greenbrier, '65 Corsa, '66 Corsa
  '69 Road Runner, '09 Ford F-150, '99 Neon R/T
  Kid cars: 00 Grand Marquis, 00 Miata
"Why do something if you're not going to obsess about it?"