Brake schematic

This page is a start, but would be best to find someone local to be able to see their car. Are you in Baden, Germany? If so, contact Roland jaeckel (willibillie at live.de). He'll have any parts you need, as well as the requisite expertise.
http://www.panterasbywilkinson...s/catalog/ill3b.html

Thanks ! ☺ It seems that I miss some parts.
Is there a non oem solution for the brake system? Is there any aftermarkt brakelightswith and valves and other parts ?

I've heard of owners replacing the brake switch (part # 23-A) with a microswitch actuated by the brake pedal arm.

What is part no23 ?

that is the brake line to the back brakes.
I installed a micro switch to the pedal assembly, it was incredibly easy and works like it should. The slightest movement on the brake pedal trips the light.

Perfect. A microswitch is a verry good idea!
But what is the small number 23?
Looks like a brake fluid distributor?

23 is the brake proportioning valve with brake light switch. With 23a being the brake light switch.

Mike

#23 is a distribution block. #12 is the proportioning valve.

Of course, you're right. Shuttle valve was the name I was looking for. This is the one that limits braking to one end or the other when it "clicks" because of a pressure differential between the front and rear brake systems.
This is the one people often take out when they redo the system.
Sorry, pic is hard to read due to size limitations. Just search "Pantera shuttle valve" and it will show you a good pic.

Mike

shuttle valve is correct, not distribution block.

Tony

More on the brake shuttle valve here...
http://www.panteraplace.com/page89.htm

Thanks ☺
This means the only funktion from part 23 is a warn light ?
So we do not need this?

Thank is my OPINION.

I have heard mention when spool shuttles due to fluid leak it will reduce the loss of fluid during latter braking.

I don't see that if the spool is as per the above. However I have heard reports of difficulty in bleeding brakes if shuttled

quote:

Originally posted by GT4Peter:
Thanks ☺
This means the only funktion from part 23 is a warn light ?
So we do not need this?

Correct. Part 23 is not needed.

Since this shuttle valve activates on a pressure differential, could a rear brake proportioning valve between the master and the
shuttle valve cause the shuttle to move?

At this point my question is merely theoretical, but I think I ought to look at where in the line I put my valve....

Rocky

Part 23-A is the pressure differential (shuttle valve) switch.

Part 28 is the brake light switch.

John

Will it works also when the master cylinder is damaged? Maybe only when you have not exact the same pressure?

Is there any option, to build in a modern master cylinder for 4 brake lines? So in case of loosing brakefluid that you are more safe?
It should brake left front and right rear / left rear and and right front.

Peter, the shuttle valve and its plumbing is, sort of, a safety device. It moves when fluid flows more to one end of the brake system than the other (differential flow). This can happen with worn pads on one caliper, a slight leak at one caliper or joint, or during brake bleeding. The 'safety' aspect is, the shuttle grounds at the end of its travel and turns on a red warning light on the dash. Trouble is, several other circumstances also turn on the same warning light... and one cannot easily sort out exactly what's happened without getting out of the car and physically investigating.

Additionally if the shuttle valve travels clear to the end of its bore, this particular valve is prone to stick there, as the shuttle has no return springs. Sticking comes from a failure to change fluid on a yearly basis; water in brake fluid tends to form varnish in unused areas of the brake plumbing. If the shuttle is stuck at one end of it's bore, fluid flow is severely restricted to that pair of calipers, and stopping power suffers badly. The car may 'pull' from one side or the other in a panic stop.

A conscientious owner will 'pre-flight' such a high-speed sports car before starting the engine: check brake & clutch fluid levels, pad thicknesses and tire pressures at a minimum. So the safety aspect of the stock valve is not really necessary.

All the above is why a number of owners have completely removed the shuttle valve AND any non-adjustable (stock) brake proportioning valve from their Pantera, replumbing their brakes for full pressure to the fronts rather than the as-stock configuration to the smaller rears. Many safety-related articles over the years expand on all the above.

quote:

Originally posted by Bosswrench:
...If the shuttle is stuck at one end of it's bore, fluid flow is severely restricted to that pair of calipers..Many safety-related articles over the years expand on all the above.

I know the schematic shown is generic, but I don't see the flow being restricted sense there are the through passage is blocked with the reduced diameter and thus fluid goes around.

After saying this, I did find an online photo of the spool removed and it is differernt. I would like to see the internals myself, but it looks as if the right side spool would slide into the removalable end cap and THAT could provide a significant fluid block. I then assumed one side does need to be blocked when a leak occurs since the master cylinder has a floating front piston and required rear piston pressure to provide force to the front piston.

BUT, looking at the tubing arrangement, the rear MC piston discharge goes to the removalbe end cap and thus if the shuttle failed to the right, appling rear MC pressure would push the spool back and allow fluid out the leak.

Would this be more accurate?

Here are pics of the actual Pantera shuttle valve.

John

Note that EACH end of the shuttle valve has a shallow groove. Should one brake "circuit" fail, the valve moves to the failed (low pressure) side and RESTRICTS fluid flow to that "circuit".

Repeated applications of the brake pedal will eventually empty ONE of the master cylinder's reservoirs, but the dam within the master cylinder's reservoir will retain sufficient fluid to operate the non-failed circuit.

John

I by passed this failure prone piece and installed a Wilwood piece I will show pictures tomorrow, but go to http://www.wilwood.com/MasterC...rCylinderValves.aspx
Their proportioning valve and bracket are the best i have ever seen and I love mine! I flipped the bracket so it sits on the passenger side of the master. Another thing if you don't want to install a micro switch for your brake light, it has the switch right on it.

here is my attempt at making a functional shecmatic of the brake system. Sorry about the mix of illustration types as I used as found examples.

Please comment if there is something in gross error

and while I had my crayons out

What's the color code on the front one? is there one?

Pink and Teal to the front circuit?

quote:

Originally posted by Rocky:
What's the color code? is there one?

Nope---Just Different and Diverse