TV Vixen S2 Brake line assembly

[Soldaat van O.]

Hi all,

I'm having some trouble wit the brake line assembly for a Vixen S2
Due to a fire in the engine bay a new master cylinder has been placed. But for some reason the lines have gone missing over the years. There should go two lines from the master brake cylinder to some kind of a distributor mounted on the chassis. I Have most lines in place but I cant figure out to wich ports the two lines from the master brake cylinder are attached.


This is the distributor( don't know the exact name for this part)

1. goes to left front caliper
2. goes to rear calipers
3. is open and goes to master brake cylinder but don't know wich one
4. is open and goes to master brake cylinder but don't know wich one
5. goes to right front caliper


I was to attach another pic of the master brake cylinder, but for some reason it doesn't work. Anyway it has two outlets. One near the base and one next to it. Those should connect to ports 3 and 4 on the distributor.

Who can help me out?

[heightswitch]

Soldaat van O. said:

Hi all,

I'm having some trouble wit the brake line assembly for a Vixen S2
Due to a fire in the engine bay a new master cylinder has been placed. But for some reason the lines have gone missing over the years. There should go two lines from the master brake cylinder to some kind of a distributor mounted on the chassis. I Have most lines in place but I cant figure out to wich ports the two lines from the master brake cylinder are attached.


This is the distributor( don't know the exact name for this part)

1. goes to left front caliper
2. goes to rear calipers
3. is open and goes to master brake cylinder but don't know wich one
4. is open and goes to master brake cylinder but don't know wich one
5. goes to right front caliper


I was to attach another pic of the master brake cylinder, but for some reason it doesn't work. Anyway it has two outlets. One near the base and one next to it. Those should connect to ports 3 and 4 on the distributor.

Who can help me out?

Use a Cortina Mk 4 / 5 master cylinder instead and do away with the remote valve.

n.

[Soldaat van O.]

heightswitch said:

Use a Cortina Mk 4 / 5 master cylinder instead and do away with the remote valve.

n.

I don't think the owner aggrees with that. He allready installed a new Lucas master cylinder.
What would be the issue when keeping the remote valve?

[youngnick]

I found these pages very useful:

http://www.buckeyetriumphs.org/technical/Brakes/MCPDWA/MC.htm

http://www.zen11896.zen.co.uk/vixen/parts/pdwa.html

Alan

[Slow M]

The valve, if memory serves, is a safety valve.
If one circuit were to fail, the pressure differential inside the valve would force the plunger/piston over so that the side that is still functioning would retain pressure.
Do not simply delete this!
B.

[heightswitch]

Slow M said:

The valve, if memory serves, is a safety valve.
If one circuit were to fail, the pressure differential inside the valve would force the plunger/piston over so that the side that is still functioning would retain pressure.
Do not simply delete this!
B.

Which is the reason I advocated throwing the antiquated old st away and using a twin circuit cortina master cylinder!!

N.

[GAjon]

May help? Early 3000M set up, might not be correct for you.



John

[Seabass]

Slow M said:

The valve, if memory serves, is a safety valve.
If one circuit were to fail, the pressure differential inside the valve would force the plunger/piston over so that the side that is still functioning would retain pressure.
Do not simply delete this!
B.

The shuttle valve is simply to operate a switch (not connected above!) to light the brake warning lamp on the dash. It has no functionality in relation to retaining pressure (in fact if it's old it could cause a breach between the two circuits and a total failure). The system is split front/back from the two different bores in the master cylinder (as you can see thanks to John above). The circuits pass through the shuttle valve on either side of the shuttle. If one circuit fails it doesn't affect the other.

Therefore the only advantage of a device that didn't work well from the factory and continues to give problems is to provide a warning light on the dash.

A later fluid level float sensor cap for the master cylinder would provide identical functionality and improved safety in my humble opinion.

Edited by Seabass on Wednesday 4th November 08:37

[heightswitch]

Seabass said:

Slow M said:

The valve, if memory serves, is a safety valve.
If one circuit were to fail, the pressure differential inside the valve would force the plunger/piston over so that the side that is still functioning would retain pressure.
Do not simply delete this!
B.

The shuttle valve is simply to operate a switch (not connected above!) to light the brake warning lamp on the dash. It has no functionality in relation to retaining pressure (in fact if it's old it could cause a breach between the two circuits and a total failure). The system is split front/back from the two different bores in the master cylinder (as you can see thanks to John above). The circuits pass through the shuttle valve on either side of the shuttle. If one circuit fails it doesn't affect the other.

Therefore the only advantage of a device that didn't work well from the factory and continues to give problems is to provide a warning light on the dash.

A later fluid level float sensor cap for the master cylinder would provide identical functionality and improved safety in my humble opinion.

Edited by Seabass on Wednesday 4th November 08:37

Like the Cortina Mk4 or 5 one which fits directly to the Triumph servo perhaps!
Its hard work sometimes is this forum business james.

N.

Edited by heightswitch on Wednesday 4th November 11:40

[Slow M]

...makes me wonder how much more junk is floating about up there that's based on figment?

[TVR_owner]

Loads and loads and loads...

[Seabass]

heightswitch said:

Like the Cortina Mk4 or 5 one which fits directly to the Triumph servo perhaps!
Its hard work sometimes is this forum business james.

N.

Edited by heightswitch on Wednesday 4th November 11:40

Yep you could as part of refresh. The Cortina cylinder seems a better design and outlasts the Triumph unit apparently - but both are still dual circuit. I was referring to the PDWA function more than anything.

Hard work? Anything that's worth doing is hard work!

James

[Seabass]

If you want to keep the unit:

The brake lines should pass through each side of the switch (translucent plastic thing).

This is the older version of the PDWA:

Soldaat van O. said:

Hi all,

Connecting it as you suggested would mean that 2 -> 5 = no braking.

This is what's called a 5-port PDWA as used by Range Rover. It needs to be connected as follows;

1. Line to Left Front Calliper
2. Line from M/C Rear Brake Port (furthest from servo)
3. Line from M/C Front Brake Port (nearest the servo)
4. Line to Right Front Calliper
5. Line to the Rear Wheel Cylinders (to T Piece at rear)

Edited by Seabass on Wednesday 4th November 17:11

[Soldaat van O.]

Thanx for all your replies. They are very helpfull, I will talk to the owner about keeping the remote valve.

Here's a pic of the Master Cylinder. it has dual outlets. Can I still use this when letting go of the remote valve?

[Soldaat van O.]

GAjon said:

May help? Early 3000M set up, might not be correct for you.



John

This seems to be the right setup when keeping the remote valve