You've got me pretty confused here. You've set up a two-MC system and
you have proportioning valves on it? What are they proportioning?
Most folks that do two MC brakes do the proportioning with a balance
bar. A proportioning valve reduces downstream pressure. In a single
MC system so you can put it between the front and rear systems to have
less pressure applied to the rear cylinder than the front. I don't
know what they would be used for in a two mc system, and I assume
that's your problem.
Placing a proportioning valve in the rear circuit only generally does
work since it reduces the pressure at the rear brakes, but it gives a
hard pedal. You'd be better off getting rid of the proportioning
valves entirely and using a balance bar. I'm assuming you feed the
front from one MC and the rear from the other. If this isn't the case,
then do.
On May 20, 2008, at 9:02 AM, Robert D. MacKenzie wrote:
> I have having some issues with a Tilton dual brake master cyl
> installation I singley
> started over the weekend on my Spitfire Racer
>
> I bought two used 1 inch Tilton masters with all the correct
> brackets/mounts
> with remote reservoirs plus two Wilwood proportioning valves to be
> installed
> on my Mk1 spitfire, replacing the original single circuit master.
>
> The cylinders were rebuilt using the correct Tilton kits. I made up
> new
> lines from the master outlets to the valves and then into the
> existing brake
> lines.
> Everything went well until the final bleeding process began.
>
> The 1st time I tried to bleed the front first then the back. The
> front
> brakes felt fine with good travel and pedal feel. But when I tried
> to bleed
> the backs the system would bind and I had a very high pedal effort.
> When I
> blend the backs with the fronts open they worked fine by
> themselves. When
> everything was closed the system will bind with very high pedal
> effort but
> no brakes. Not good.
>
> I then tried bleeding both systems at the same time, and that seemed
> to work
> until I closed off all the speed bleeders and the system would bind
> again.
>
> I believe that the master cyl providing pressure to the front brakes
> caused
> the pistons to press the calipers closed before the rear ones can
> apply the
> rear brakes. Making adjustments to the proportioning valves does
> not seem
> to make any changes. I also tried adjusting the bracket connecting
> the two
> pistons to the pedal to push one in earlier than the other but that
> did not
> make a difference. Swapping the cylinders or the valves side to side
> made no
> difference. I believe each individual component is working right,
> just not
> together.
>
> Before I go much further I have some basic questions:
>
> Are two 1 inch masters the way to go? Do I need to run a smaller
> cylinder
> on one side or the other? Do I need two valves or will one suffice
> as the
> other will always be open?
>
> Any help/advice will be appreciated.
>
> Thanks
> _______________________________________________
> http://www.team.net/donate.html
>
> Fot mailing list
> Fot@autox.team.net
> http://autox.team.net/mailman/listinfo/fot
>
> You are subscribed as billb@bnj.com
Bill Babcock
Babcock & Jenkins
Billb@bnj.com
503.936.7660
www.bnj.com
_______________________________________________
http://www.team.net/donate.html
Fot mailing list
Fot@autox.team.net
http://autox.team.net/mailman/listinfo/fot
|