Board logo

Bias bar concern
Paradoxia0 - 1/6/07 at 09:50 PM

Hi All

With my impending SVA test on Tuesday I though it was about time to setup my brake bias bar.

Good move in one way but a bad one in another....

The sperical bearing (in the tube on the back of the pedal) freely drops out of the left hand (passenger) side and I cannot see any way to hold it in there!

I started reading this thread and I am beginning to think that it might be put together wrongly...

Should the two celvices be virtually up against the tube on the back of the pedal or about 40-50mm away as they are on mine?

Also, I have seen on other threads that people are using 0.700" master cylinders on the rear and 0.625" on the front... Should I be doing the same with my Viento?

Not ideal realising this at 11pm the Friday night before the test on Tuesday!

Any input would very greatly appreciated!

Mark


Paul (Notts) - 1/6/07 at 10:01 PM

Mine are just a few mm away.

cant remember the site that tells you how to set them up but some one will help.

I have had too much wine to recall detail

Paul


davrus - 1/6/07 at 10:02 PM

I have no answers for your questions but good luck on Tuesday.


jambojeef - 1/6/07 at 10:04 PM

Hi,

See this:

http://www.rallydesign.co.uk/catalog/balancebar.php

Mine are 0.625 and 0.7" and Im running sierra discs and calipers all round.

What calipers are you using?

Geoff


andrew-theasby - 1/6/07 at 10:07 PM

When you push the clevises to the extremes of 1 fwd/1 aft they should just touch the tube so there is no sideways play, but in theory if they ever move this far in use you need to change one of the master cylinders to make them more similar (or the bias is way off of course) Your ideally looking for it to stay pretty straight in use, by turning the threaded rod so the spherical bearing is in a position where you get more front bias. If the master cylinders move different distances (by quite a bit) then you should change the size of them. Hope this helps


Paradoxia0 - 1/6/07 at 10:16 PM

I am really not sure...

Been going through my invoices trying to work it out but they were bought as a kit from Luego and the invoice doesn't say...

I'll pop down and see if I can find out....



Damn that garage floor is cold! but a result. It is 0.625" front and 0.700" on the rear.

First thing tomorrow I think I need to adjust the clevice right in from what Andrew and the link Geoff post say and see how that goes. I assume you can remove the clevis from the cylindar without taking everything to pieces else tomorrow is going ot be a long day...

Thanks

Mark


andrew-theasby - 1/6/07 at 10:32 PM

Yep, with the brake pedal back, you should be able to spin the rods to the m/c's and undo them from the clevises, then just adjust the gap from clevis to tube. Screw m/c rods back in, then try the brakes. Adjust the bias by turning the threaded rod through the middle, which moves position of the spherical bearing. When happy with the amount of bias, just look at the pedal and make sure the bar isnt moving to one extreme in operation. Job done, easy as that


MikeRJ - 1/6/07 at 11:36 PM

Yes, the clevises should be virtualy touching the tube that holds the spherical bearing. If not the whole assembly will just flop around uselessly.


RazMan - 2/6/07 at 07:49 AM

Make sure you leave enough slack between the washers and clevises. Rally Design specify 40 thou I think, but just back off one clevis about 1-2 turns from tight and double check that the whole assembly doesn't bind when pressing the pedal.

p.s. I can't see how your spherical bearing can fall out of the tube when assembled, so I suspect you need to compare some pictures from the other thread.


Johnmor - 2/6/07 at 01:45 PM

This might help, Mine seems Ok , passed SVA no problem.



Bob C - 2/6/07 at 06:10 PM

On the pic above, the 'floppiness' is due to there being no location for the ends of the bias bar in the vertical plane. If it's loose enough to do the biasing thing without binding then the ends can move vertically inhindered.
When I made my elan (many years ago...) I included a link from the pedal pivot bar to the end of the bias bar to locate in this direction and that worked fine. I've never seen it anywhere else, just floppy systems.....
Bob


Paradoxia0 - 2/6/07 at 09:54 PM

Hi Guys

Thanks for your advice.

I have now adjusted the bias bar to as Razman (and others) recomended and it feels better. Infact the front wheels now lock on heavy breaking - even on tarmac! (Before you pressed the pedal as hard as you could and found that praying had a greater effect!)

Fingers crossed that the 1/2 tonne of rubber trim that I added today doesn't push the weight up so hight the brakes stop working again

Oh, and that when the engine is setup professionally on Monday me emissions drop to acceptable limits for the SVA on Tuesday!

Thanks again

Mark

BTW, thanks for the piccy Johnmor. I think looking at that that an attack of the hacksaw may be in order on mine. My bias bar is sticking out a good 50 - 60mm on the front cylindar side!

[Edited on 2/6/07 by Paradoxia0]


wilkingj - 3/6/07 at 08:26 AM

Front wheels MUST lock up before th rears, its a SVA fail.

Also I did my clevis's up too close to the pedal tube. This meant they restricted the movement of the bar in the tube, ie the clevis's were so close the bar could not pivot properly. You must have a small gap.

But the front brakes locking before the rears is the acid test. You need someone to watch the wheels for you when you test.

Also the locking nuts must be Roll Pinned. Split pins and extra lock nuts wont pass.

That lot cost me 2 extra SVA re-tests at £30 each.
Got there in the end.

Hope it goes OK for you.


ady8077 - 3/6/07 at 09:17 PM

Hi

Quote :The sperical bearing (in the tube on the back of the pedal) freely drops out of the left hand (passenger) side and I cannot see any way to hold it in there!

Isnt the bearing held in the tube with a circlip?

Adrian


andrew-theasby - 3/6/07 at 09:33 PM

No, the circlips hold the bar into the bearing. The bearing needs to be a free fit in the tube.

wilkingj, can you explain where the roll pins must go please, or even post a pic if you have one. Im not quite sure where you mean, and i would have used split pins all over. Thanks