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Brake Thingy
tr - 5/2/05 at 06:41 PM

Just trying to sort my brakes out properly and I've found this bit that needs plugging into the rear circuit somewhere. I've forgotton it's name, but I know it's used to stop the back wheels locking. I hearby declare it named a brake thingy.

Anyway, does anyone know which way round it should go?



Does the master cylinder go at A and the slaves at B or is it t'other way round?

Does it need to be mounted in any particular orientation? It would fit best horizontally...

Cheers Lads.

tr

[Edited on 5/2/05 by tr]


theconrodkid - 5/2/05 at 06:50 PM

its a decel valve,opinion is it wont work on a 7,if you do need a valve(some do,some dont)use an adjustabubble one from a fiat uno


Avoneer - 5/2/05 at 06:52 PM

If you are using drums on the back and discs on the front, you will not need it.
Pat...


tr - 5/2/05 at 07:04 PM

quote:
Originally posted by Avoneer
If you are using drums on the back and discs on the front, you will not need it.
Pat...


Excellent news!

Is there any reason it won't work/ isn't needed in a 7?

Cheers


Northy - 5/2/05 at 07:12 PM

It relies on the front of the car dipping under braking to move the ball bearing in it to the front to reduce pressure.

A Locost doesn't wollow about like a large Sierra.

Cheers


tr - 5/2/05 at 07:20 PM

Genius!

That'll explain why it rattles too.

Question answered and still time to go to the pub!

Thanks!

tr


JoelP - 5/2/05 at 07:27 PM

hence the mounting angle is also important. as said, stuff it and follow the crowd, uno bias valves are in commom use.


britishtrident - 5/2/05 at 07:41 PM

quote:
Originally posted by Northy
It relies on the front of the car dipping under braking to move the ball bearing in it to the front to reduce pressure.

A Locost doesn't wollow about like a large Sierra.

Cheers


Its a G valve the main thing that makes it work is deceleration "G" force so set at the correct angle it will work in any car it just isn't needed in a 7.

[Edited on 5/2/05 by britishtrident]


Dick Axtell - 6/2/05 at 11:11 AM

Guys,
One more time - BIN IT!!

Please do not use this valve. Its not suitable for 7-type vehicles. Plus, you need to establish the necessary decel level, and this requires considerable instrumentation, decel sensors, suitable data logger, and weeks of test work.

For those of an iquiring mind, here's the theory of how this valve works - allegedly!! Rescued attachment G_Valve02.jpg
Rescued attachment G_Valve02.jpg


tom_loughlin - 6/2/05 at 12:22 PM

ive put one on my car - i have discs all round - if you guys all suggest binning it, whats the best alternative?
tom


greggors84 - 6/2/05 at 01:05 PM

Alot of people use fiat uno adjustable ones. Search for a thread on them as im not sure what unos they come off.

Ive used a wilwood adjustable one, picked it up second hand so wasnt that expensive.


Liam - 6/2/05 at 01:53 PM

I'm coming up to having to work out my master cylinder sizes and getting some. I've got discs all round but have a balance bar in the pedal and will be able to choose whatever master cylinder sizes will be correct (once I work out how). Is it still a good idea to have a decel valve in the rear circuit with this kind of setup?

Cheers

Liam


Peteff - 6/2/05 at 04:15 PM

Kind of defeats the object of having a bias pedal box and setting it up.


tr - 6/2/05 at 07:29 PM

Blimey, didn't mean to start an argument!

Said item has been binned now. I'm going to try it without for now and see how it looks once it's running. (One day)


britishtrident - 6/2/05 at 09:01 PM

Fit a Fiat valve it is simpler to set up.

The Girling G valve isn't that hard to set no harder than anyother brake presure regulating system (try setting up the Teves load sensing valve Chrysler UK used in the 70s) BUT it isn't SVA friendly the Fiat Uno one is and its cheap.
If you do a search you will post showing the bracket and adjustment mech you will also find some stuff I wrote up on who to get the correct setting -- do the road testing this carefully starting from a front bias.
For safety Front brakes should always lock first in all conditions.


britishtrident - 6/2/05 at 09:07 PM

quote:
Originally posted by Liam
I'm coming up to having to work out my master cylinder sizes and getting some. I've got discs all round but have a balance bar in the pedal and will be able to choose whatever master cylinder sizes will be correct (once I work out how). Is it still a good idea to have a decel valve in the rear circuit with this kind of setup?
Cheers
Liam



Not really --- just make sure you know how to set up the bias bar --- and make sure the side clearance is set to 0.025" (0.4mm) to ensure you still have brakes on one circuit if the other fails.

Bias pedal boxes are designed around 0.7" and 0.625" dia master cylinders --- generally 0.7" are better bet for disc system to avoid excessive pedal travel.

One thing about bias bars and cut off valve once you get them set don't twiddle ven for racing the difference between wet and dry settings is usually either 0.5 or 1 turn wet needs more bias towards the rear.


[Edited on 6/2/05 by britishtrident]