The curious case of the Atom 4 brakes

[plip1953]

These are the bleed valves referred to by @plip1953. Seem level when on the ground, but on axle stands it might tip them the wrong way? Vacuum on the bleed valve would sort or just keep rear jacked for final bleed?

Yes, the bleed valve needs to be at the highest point of the MC to ensure any trapped air can/will escape through the bleed valve.

[mynamesnotbob]

Yes, the bleed valve needs to be at the highest point of the MC to ensure any trapped air can/will escape through the bleed valve.

Would find it odd if that wasn't in the normal factory bleed procedure, including tapping callipers and MC's with a rubber mallet to knock any bubbles to the top though, but who knows, maybe it was a simple oversight as the previous cars had a the MC's in positive rake

[speedmachine]

We are all guessing here, but in the payed member section is the answer written, right?

[John Scherrer]

No, there’s no description of any factory magic bleeding process!

[mynamesnotbob]

We are all guessing here, but in the payed member section is the answer written, right?

Not guesses but conversation. And no there wasn't an actual answer in members section hence it continued here

Plenty are now reporting that the 'new bleed' resolves the long travel issue, which I presume is calliper bleed and MC bleed with correct orientation to not trap bubbles

My car is in for service in a few weeks, so will report back - if this fixes it I will confirm the procedure with the factory, as I will not transport my car to factory over 200 miles away every time I bleed the brakes. And if it doesn't I will swap MC's as previously discussed

All good conversation and hoping it drives traffic to the forum as its a great resource and actually searchable and usable unlike Facebook

[speedmachine]

We are all guessing here, but in the payed member section is the answer written, right?

Not guesses but conversation. And no there wasn't an actual answer in members section hence it continued here

Plenty are now reporting that the 'new bleed' resolves the long travel issue, which I presume is calliper bleed and MC bleed with correct orientation to not trap bubbles

My car is in for service in a few weeks, so will report back - if this fixes it I will confirm the procedure with the factory, as I will not transport my car to factory over 200 miles away every time I bleed the brakes. And if it doesn't I will swap MC's as previously discussed

All good conversation and hoping it drives traffic to the forum as its a great resource and actually searchable and usable unlike Facebook

I think you misunderstood my tone. I didn’t mean anything bad. I was just frustrated that this conversation was costing you guys energy, while I thought there was a mention in the private section with the solution (as that was the extra “value” for paying members) but I guess that value was not giving the solution

[mynamesnotbob]

I think you misunderstood my tone. I didn’t mean anything bad. I was just frustrated that this conversation was costing you guys energy, while I thought there was a mention in the private section with the solution (as that was the extra “value” for paying members) but I guess that value was not giving the solution

Its all good! I'm pretty pro forum - so getting a bit of debate going is good IMO. Always happy to share, worst case someone knows the brakes can be better, best case someone learns something.

[plip1953]

There is no guessing or magic involved!

For any regular hydraulic braking system to work optimally you need to expel every last molecule of air. And that's it.

How you achieve that can be a bit a bit of a mare, especially when the system is first filled, but thereafter it's just another routine serving task.

With all the air out of the system the pedal will feel as firm as it can be given the various components chosen by Ariel ie pedal box, MCs, lines, calipers and pads, together with how they are sited and secured physically. And it's only if the pedal still doesn't feel how the owner/driver wants it to feel should there be any need to look further at what further is possible - which is quite a lot.

[robfitz]

Had my service today and the pedal is nice and firm. In fact it is now harder to heel and toe as the pedal is higher up, will need to get that adjusted, but the brakes feel much better.

Had a very pleasant day all told.

[mynamesnotbob]

Excellent news, did Steve share what they’ve changed in the procedure?

[Florentm]

Hello,

I also found that the bite and travel were not good when I received the car from the previous owner.

I was thinking about bleeding the brakes but first I swap the mintex stock pad for Ferodo DS uno and it was a lot better (bite is perfect and travel issue has been solved by pushing the piston all the way back like on a bike )

Hope it can help

[plip1953]

........... and travel issue has been solved by pushing the piston all the way back like on a bike.................

What exactly do you mean by this? The master cylinder piston? Caliper pistons? Did you change pad compound on both front and rear?

[Lew]

@IanG & @Winmoz thanks for the insight and pic of the AP + Alcon setup. I have the rear ‘sport’ brake and Alcon setup but was considering upgrading the rears too, though I mainly drive on the road... I’ve found on occasion if the bias is too far forward (great for initial bite) the rear wants to come round under very heavy breaking in some conditions. If I move the bias too far back then the performance is a bit underwhelming and I loose a bit of pedal when first applying the brake... would interested to hear how the new combo goes or if anyone has any other alternatives!

Cheers.

I've bought the rear brakes upgrade for my atom 2 some month ago, didn't have time to put them on yet but I've been given the AP racing and said alcon are not available anymore.
I do hope the brake feel is better even with the AP setup since I've mostly bought the upgrade for the hard pedal feel.
[mention]Winmoz[/mention] did you feel a difference now?

[Preseh]

Just had the brakes sorted on my 4 and wow, what a difference I have to relearn how to properly drive this thing now especially heel and toe. The brake pedal doesn't get anywhere near the level of throttle pedal so may have to look at adjusting.

Expecting a few lock ups at Bedford on Friday

[plip1953]

Why did you think the "upgrade" would give you a harder pedal feel? With no other changes except discs and calipers I'd mostly likely expect the pedal to be a bit longer, although not harder or softer. To get the hardest possible pedal you need to ensure the system has been bled until the very last molecule of air has been removed, and a longer or shorter pedal travel is primarily down to master cylinder sizing, although the choice of brake pad compound may also have a bearing on matters.