Technical stuff > Brakes

Beta handbrake not holding vehicle on a slope

<< < (2/5) > >>

JASPER_40:
Hi Guys…… just a thought.

Will a failed adjuster spring on just one caliper render the handbrake to inoperative on both sides ? I would think not as the handbrake is an emergency brake after all. I reckon the handbrake would hold on the side with the good adjuster.

Another thing that may cause the adjuster to be poor is the piston rotating as the handbrake is applied. There is a lug on the back of the brake pad that fits into the slot on the piston face plate n order to stop the piston from rotating.

I presume this lug is present on the brake pad and located in the piston slot that is set horizontally ??

Just a random long shot

Steve

Nigel:
Steve,
With one failed adjuster it's likely you'd get a compromised handbrake performance
as the cable would move through the U channel.
Of course each caliper is independent so braking effect would be greater on the good side.

The piston doesn't rotate. As you said its held by the pad lugs. It's the screw part that does that.
And the central screw can only rotate in one direction (so long as the tag is not broken) as
the spring grips in the other direction.

Nigel

JASPER_40:
Hi Nigel, intreagued by this thread as I am having all manner of problems with trying to get my brakes to work well enough to pass an inspection. 

Just to add to my previous post, the piston can't rotate but only because the lug on the pad prevents it from doing so leaving the adjuster nut to take up any slack by rotating. Any slack uptake is held in position by the adjuster "spring" which is more of a tightly wound coil around the adjuster nut to prevent it from rotating when the tension in the handbrake is released. We both are on the same page with this.

What I was interested to also check was that the Pads actually had this lug. The long shot being that it may be possible to buy a pad which "fits" but which doesnt have the lug for cars that dont have this self adjusting mechanism. The net effect being then that the piston could then possibly rotate when the handbrake is applied and therefore render the handbrake ineffective.

On a different train of thought......a curious theory maybe ?
If Andrew's brakes work Ok hydraulically on both sides and therfore it is just the mechanical handbrake that is not holding...then if you were to push hard on the brake pedal to take up any mechanical slack and ( with the pedal still pressed ) then pull on the handbrake........would the handbrake then work at this instant  ie handbrake only lifts part way as normal.
The thinking here is that the brake pedal moves the piston to contact the rotor / disc and in doing so moves the adjuster nut accordingly making the handbrake operative in that position and circumstance. (The piston and adjuster nut are essentally fixed together but the adjuster has the ability to rotate within the piston).

So if the handbrake appears to work as per the above then you have a broken adjuster spring ...or a missing lug and possibly on both sides.

Just a final thought....I cant explain why, as Andrew said,  there is no drag at all on the disc when handbrake is off and brakes off. A functioning caliper should alwars drag ever so slightly.

Thinking about this made my time in the Gym pass so quickly today....thanks Guys

Cheers,

Steve

Gromit:
Steve,

I have tried to get the handbrake to work by pressing hard on the brake pedal at the same time. I tend to do this instinctively as we probably all do on a steeper slope to help get a good handbrake engagement when parking. It did NOT seem to improve the handbrake engagement performance unfortunately. Not sure whether that actually adds to or subtracts from the likelihood of another broken adjuster spring in one of the rear calipers.

When I took the car back to the workshop to get the handbrake cable adjusted some months ago, (thinking that the newly fitted cable might have stretched a bit), hoping that would solve the handbrake under performance, I don`t recall checking that BOTH rear wheels were locked tight, just the right hand one, when observing with the mechanic while the car was on the hoist. Perhaps it would pay to get the car back on the hoist and check whether there is a discernible difference in the degree to which each rear wheel is securely locked when the handbrake is engaged as well as checking handbrake lever travel in every respect: evenness of travel and adjustment etc.

Re no rear caliper drag comment, I meant that there was no evidence when driving the car of caliper failure to the point that the caliper dragged excessively when the handbrake was released and no brake pedal pressure applied ie no telltale metallic scraping or grinding noises that should not be there.  I am assuming that the car is set up correctly with the right pad to rotor distance or proximity when the brakes are in the "disengaged" position. We are talking about a workshop with decades of experience.

Something is clearly not right though which warrants a re-inspection of everything I guess. Presumably other Beta owners have a handbrake that works as it should?

By the way the new pads on the rear are TRW (standard 'Cotec') GDB155 ones, specifically for the Beta. They were the only ones I could source readily in Australia. The front pads fitted are Australian made Bendix General CT ceramic type for low dust and rotor wear. Bendix Australia no longer make rear pads for the Beta (deleted catalogue line).

Andrew

JASPER_40:
Damn it .....I need to get back to the Gym to have another think about this

Navigation

[0] Message Index

[#] Next page

[*] Previous page