Brake Upgrade Options & Ideas

[cb750]

Great!

[Guest Ian & Carole]

Well done "Percy"

[Dean Roberts]

Well done "Percy"

Don't u mean Thomas???

[Guest Ian & Carole]

Don't u mean Thomas???

"verance"

[Dean Roberts]

"verance"

 

Very clever... I was looking to deep into the reference to Chuffing and Thomas the Tank...

 

Never clicked about the try and try and try and try again until you succeed...

[Guest 2b cruising]

Persistence spells success.

Don't know how cos it's not even an anagram.

[Guest mower man]

Pat Ian Ence is his best mate!!! mick

[Dean Roberts]

I've been back on the rollers for some more brake tests last night.

 

Rear Brake readings

According mechanic/rollers the 1st time (MOT fail):

• 52
• 49

2nd attempt after rebuilt drums (MOT fail):

• 101
• 100

After balancing upside down with a LED touch in my mouth and mastering the art of pedal operating with my forehead I found the brake bias bar catching on the pedalbox and crooked push rods going to cylinders. I adjusted the balance bar to free up the binding and aligned the rears brake push rod in a more suitable position.

 

Crooked rods slightly straightened:

 

 

You can see on the left of the clevis where the paint has been scuffed:

 

 

And yes the pictures are upside down...This was my view when adjusting and taking pictures.

 

3rd attempt after quick adjustment of the bar:

• 153
• 150

An MOT pass (barely).

 

What is even better, was that now the front brakes are registering even higher on the rollers.

A great learning curve, involving something that's just as important as going faster - Stopping power.

 

The proof in the pudding was when I returned home I attempted an emergency stop.

Which to mine and Nikki's amazement locked up and slid in a controlled fashion.

 

 

Now to get the MOT booked and then just a few final adjustments:

 

A couple of large washers on either side of the balance bar (to stop any chaffing) and re-thread it correctly so the push rods are perfectly straight with the cylinders.

I might even fit a remote adjuster on the dash, to stop any more head stands in the foot well area

Edited June 28, 2016 by Dino

[brumster]

<sigh> Bias pedal boxes. As many pointed out on here, they need to be setup carefully and accurately, otherwise they are a pain in the royal arse. They are so often misunderstood. Glad it's sorted!

[Dean Roberts]

Plenty of conflicting information online and can easily make things confusing for anybody who has never experience this type of set-up before..

 

I'm just more surprised by how much of a difference a small increment on the bias bar can be.

Either that or the alignment of the rods....Totally transformed the feel and performance from the brakes.

 

Just need to save the pennies and then look into improving the looks and performance of the fronts and upgrade the rears to disks during the SORN period.

 

 

They are so often misunderstood.

[brumster]

I would expect the bores to wear over time, given those rather non-straight angles on the master cylinders. If they were those cheapy £10-jobbies I was talking about, they would not last long in that configuration; that angle will put wear on the bore sides. Fingers crossed they will be fine

[Longboarder]

Can I refer you back to the diagrams in my post on page two of this thread. Further comment on the picture of your bias bar above is that the yokes are what control the rose joint position in the sliding tube in the pedal. The yokes must be centralised enough to almost clamp tight on the cross tube when the bar is at full swing. As you currently have it in the picture above is B awful and dangerous. The bar is still able to slide sideways and have its end baulked by the pedal box. The bar is also still able to slide sideways and give lateral movement to the ends of the bias bar that hit the pedal box and lock the pedal.

Study the setup pictures. Nothing is casually drawn. If it doesn't look like them it's wrong. It currently looks like this below. Please transform them some more.

 

Nigel

Edited June 28, 2016 by Longboarder

[Dean Roberts]

No worries guys, I have every intention of tidying this up.

 

But this being the first time I have encountered a bias bar and a non servo car, thought I would have a look at it.

 

And sure enough as per previous messages checked for the binding issue and found it to be true.

 

No worries of it being on the road yet, as it needs the MOT cert.

 

But this is far, far better than it was.

The brakes work now so just need to copy the diagrams provided.

 

I believe it's a 0.2 or 0.25 leeway allowance for the space between the pedal and clevis for the yoke to play with.

 

I'm hoping the big washers (as per Wilwood pedal box provide) will help with this and line them up better.

 

Please correct me if I'm wrong, as all this is new to me and I have no guidance except you guys.

Edited June 28, 2016 by Dino

[Longboarder]

Sorry. I went over the top. I'm still in a strop over the football! My apologies.

Not sure you can specify a separation in millimetres. How would you measure it. I found it more practical to disconnect both pushrods, fit the big penny washers and then wind the yokes in till they gripped the bar solid with the rose joint pretty well central. Then wind each yoke out one turn and check the bar angular swing. Would it move to each extreme or did the yokes jam up solid before it could? Then wound one yoke out another turn and check swing again. And then one more in my case and it was able to swing fully. It then could be locked up with a collar and locknut on the bias bar and the pushrods reconnected. By experiment I found the pushrod for the rear piston needed to be about four threads engaged and locked up and the pushrod for the front piston fully home in the yoke and then backed off one turn and locked up to prevent the pushrod stopping rotation of the yoke nipple. This left the bias bar askew with the side that works the fronts pushed toward the rear of the car at rest and the side that operates the rears sitting angled forwards. As the pedal is pushed, both pistons move forward but the rears pressure builds rapidly. This almost stops one side of the bar and the bar then pivots forward using the rears yoke as a fulcrum till equal pressure builds in the fronts. Only talking about a couple of psi at this stage and virtually no brake effect but pads and shoes have taken up all the slack. Further push on the pedal and pressure rises in fronts and rears rapidly, apportioned by the position of the rose joint which has now taken over as fulcrum. This is now all working as designed. Final balancing is by road test and unlocking and turning the bias bar to vary proportioning of the effort through the bias bar. You could always fit an adjuster wheel so you can do it on the fly. Mine is notched so self locks after each adjustment.

 

Nigel

[Guest 2b cruising]

As rugby players would say.

"football is a game played by men with funny shaped balle"