Soft brakes and spongy feel... diagnosis?

[magnet]

Re: Soft brakes and spongy feel... diagnosis?

You will not get rid of it, it is a feature

A girl at work has a Roadster and when I drove that the brake pedal has hardly any movement before the brakes come on hard and the pedal goes solid with no spongy feel to it, so I'm not so sure this soft pedal thing is a feature as it certainly isn't working on her car and her brakes feel so much better.

[BBE]

Re: Soft brakes and spongy feel... diagnosis?

Hello Fellow SmartCar Enthusiasts!

Describing the Problem:

In the last couple of weeks, a gradual deterioration of pedal feel seems to have occurred. The way this is manifested is that firmer pressure than previously required must now be initially applied to stop the car, although very firm pressure will still apply the brakes harshly enough to activate the ABS. The initial bite point of the brakes feels a little more imprecise than previously.

If I apply the brakes, release, and then immediately reapply braking, the second application of the brakes results in a more precise bite point and a firmer feel to the pedal (with a little less travel in it). The brakes feel good on the second application - certainly more of a 'normal' feel to them. If the brakes a left for a little while without touching them (just continuing down the road) then the next initial application feels soft again. Firm feeling to the brake pedal can be restored by repeating the brake-release-brake procedure.

Seeing this description, to me this is an exact description of rear brakes needing adjustment. As someone have said earlier in the thread: pull the handbrake one or two notches, then check pedal travel. If good, then this is your sole problem.
:silvertri Bjorn

[NeuroBeaker]

Re: Soft brakes and spongy feel... diagnosis?

I gave McSmarts a ring on Saturday, but they were closed over this past weekend. So I sent Sam a private message on here asking for an appointment and left all my contact details.

So I should hopefully have things sorted out in the not-too-distant future!

hmm , on my fortwo i i decided to go down the change the brake lines to braided hoses and change the fluid to dot 4 and still had the dreaded play in the top of the brake pedal , i did manage to get rid of it eventually after lots of bleeding and they feel fantastic now

Interesting - thank you. It does seem that fluid is one of the chief suspects (and sounds the least expensive to rectify).

You will not get rid of it, it is a feature

I beg to differ, Sir! :wag:

I didn't acquire the car recently and think 'hmmm, that pedal feels a bit soft'. I've had the car for a few years and know what a 'normal' feel for the Smart ForTwo brake pedal is and recognise that this is a little softer than some other cars (for comparison, my parents' BMW 3-series). Although I'm less than apt with DIY tasks, I believe the current condition has deteriorated from what I believe to be 'normal' for the Smart ForTwo - something I'm sure any SmartCar owner would spot.

If you'd driven my ForTwo, I'm sure you'd agree something is a bit amiss. :redface:

ARC - what yokos do you have/ how good are they? - only asking as I could do with opinions on tyres available in 175/55/R15's or whatever size the standard rears are...

Here you go:

Well, I seem to have hit upon a tyre that might do the job... see what you think:

Yokohama AVS db 145/65/R15 72H (front)
Yokohama AVS db 175/55/R15 77H (rear)
Yokohama AVS db Review

And they actually seem to marginally outperform the Toyos:

Toyo Proxes T1-R Review

So now I'm leaning towards the Yokohama AVS db, unless I come across a better tyre before placing an order.

Thanks for your help so far, and do let me know your thoughts on those Yokohama AVS db tyres.

All the best,
Andrew.

Those first two links are dead (but give you the specifications without clicking), although the two 'Review' links are still working and are quite helpful.

The Yokohamas are a massive improvement over the Continental EcoContacts - I couldn't recommend them more enthusiastically. They're a softer compound that gives much better grip (wet and dry) as well as a quieter and more comfortable ride. The wear rate will undoubtedly be greater, but the ForTwo doesn't do huge mileage and thus wear rates on the tyres aren't a consideration for me at all.

I informed the insurance company that I was changing the tyres, but keeping the same sizes. Their view was that they were fine with anything on the car as long as I didn't change the alloys. Still, I'm wary of insurers and asked for an updated cover note listing the tyres - which they sent out without too much fuss.

Though, do be careful at the tyre fitters - they're directional tyres and the fitters didn't realise at first... they put my rears on backwards. Fortunately, once I pointed this out they swapped the rear wheels over and it fixed the problem.

Without reading the whole string of this thread, spongy brakes are caused by the following:
Air in the brake lines
Water in the fluid
Leaking pipes
Leaking rear cylinders
Leaking seals in front callipers
Leaking seals in the master cylinder
Leaking brake pipes

That covers it. Once you've checked all that, one of those will be causing it.

Only other solution are braided hoses all round.

Thank you very much, I'll pass that along to Sam at McSmarts.

Seeing this description, to me this is an exact description of rear brakes needing adjustment. As someone have said earlier in the thread: pull the handbrake one or two notches, then check pedal travel. If good, then this is your sole problem.
:silvertri Bjorn

Thank you Bjorn, I'll give that a go.

All the best,
Andrew.

[Sam]

Re: Soft brakes and spongy feel... diagnosis?

hey sorry my net access was rubbish where i was, i was pos i sent a reply, could please email sam@mcsmarts.co.uk as it means i can reply easier :-)

[NeuroBeaker]

Re: Soft brakes and spongy feel... diagnosis?

hey sorry my net access was rubbish where i was, i was pos i sent a reply, could please email sam@mcsmarts.co.uk as it means i can reply easier :-)

OK, will do - thanks Sam!

All the best,
Andrew.

[NeuroBeaker]

Re: Soft brakes and spongy feel... diagnosis?

Just thought I'd give you guys an quick update: the car is now with Sam at McSmarts (thanks for the referral Fudge) and I'll pick it up tomorrow.

I had a little difficulty finding it at first as for some reason my GPS (which didn't have the exact postcode available to it) directed me in through the back entrance to the estate, meaning I didn't get to read the information signs at the main entrance. I called Sam who managed to direct me and soon found the place - so it's now stored as a coordinate in my TomTom and won't have any problems for next time.

Oh, and Sam has two very cute little dogs running around in his office. :dog::dog:

All the best,
Andrew.

[NeuroBeaker]

Re: Soft brakes and spongy feel... FIXED BY McSMARTS!

Hello fellow SmartCar Enthusiasts,

Just got the car back from Sam at McSmarts and all is well again!

Sam replaced the front discs and front pads (which were below legal thickness :eek, as well as bleeding through the whole brake fluid system with new fluid (washing out a milky white substance from some of it :eek. The brake pedal now feels firm again and the new discs and pads will soon be bedded in.

Sam also noticed my split rear windscreen wiper, which I'd been meaning to do something about (a trip to the Merc Dealer is sometimes difficult to manage :redface, and fortunately he had a replacement in stock.

I'm sure Sam will be seeing a lot more of Nicky (my girlfriend) and me - I must remember to ask him if he can do MOTs at the same time as servicing... I've got both of those coming up quite soon.

:thanx: Thanks Sam, great job!! In fact, have a gold star: :star:

All the best,
Andrew. :silvertri

PS:
Did I go overboard with the smilies? :redface:

[10:45PM]

Re: Soft brakes and spongy feel... diagnosis?

Come on then - how much and stuff

And did he sort the excess travel with the rears adjustment ?

[NeuroBeaker]

Re: Soft brakes and spongy feel... FIXED BY McSMARTS!

Oh yes, sorry - forgot to add that. Sam also sorted out the rear adjusters which weren't working at all, and cleaned out the rear drums.

How much? £250 (inc. VAT) for all parts and labour, which I'm very happy with - perfectly reasonable. Especially since he had to spend time running two bottles of brake fluid through my lines to flush out all the crud in them. :redface:

All the best,
Andrew.

[madDan]

Re: Soft brakes and spongy feel... diagnosis?

you were talking about the fortwo here


Quote:
Originally Posted by madDan
You will not get rid of it, it is a feature

I beg to differ, Sir! :wag:

I didn't acquire the car recently and think 'hmmm, that pedal feels a bit soft'. I've had the car for a few years and know what a 'normal' feel for the Smart ForTwo brake pedal is and recognise that this is a little softer than some other cars (for comparison, my parents' BMW 3-series). Although I'm less than apt with DIY tasks, I believe the current condition has deteriorated from what I believe to be 'normal' for the Smart ForTwo - something I'm sure any SmartCar owner would spot.


I was responding to the Roadster queries!


Beg to differ all you like you don't have the feature!

[NeuroBeaker]

Whoops... my apologies madDan.

you were talking about the fortwo here

Re: Soft brakes and spongy feel... diagnosis?

Re: Soft brakes and spongy feel... diagnosis?

You will not get rid of it, it is a feature

I beg to differ, Sir! :wag:

I didn't acquire the car recently and think 'hmmm, that pedal feels a bit soft'. I've had the car for a few years and know what a 'normal' feel for the Smart ForTwo brake pedal is and recognise that this is a little softer than some other cars (for comparison, my parents' BMW 3-series). Although I'm less than apt with DIY tasks, I believe the current condition has deteriorated from what I believe to be 'normal' for the Smart ForTwo - something I'm sure any SmartCar owner would spot.

If you'd driven my ForTwo, I'm sure you'd agree something is a bit amiss. :redface:

All the best,
Andrew.

I was responding to the Roadster queries!


Beg to differ all you like you don't have the feature!

Ahh, I see... whoops. :embarasse

Given the title for your reply post, I'd taken it as a general reply to the thread rather than a direct response to another poster. :redface: My apologies!

All the best,
Andrew.

[Sam]

Re: Soft brakes and spongy feel... FIXED BY McSMARTS!

Hello fellow SmartCar Enthusiasts,

Just got the car back from Sam at McSmarts and all is well again!

Sam replaced the front discs and front pads (which were below legal thickness :eek, as well as bleeding through the whole brake fluid system with new fluid (washing out a milky white substance from some of it :eek. The brake pedal now feels firm again and the new discs and pads will soon be bedded in.

Sam also noticed my split rear windscreen wiper, which I'd been meaning to do something about (a trip to the Merc Dealer is sometimes difficult to manage :redface, and fortunately he had a replacement in stock.

I'm sure Sam will be seeing a lot more of Nicky (my girlfriend) and me - I must remember to ask him if he can do MOTs at the same time as servicing... I've got both of those coming up quite soon.

:thanx: Thanks Sam, great job!! In fact, have a gold star: :star:

All the best,
Andrew. :silvertri

PS:
Did I go overboard with the smilies? :redface:

thanks been a while since i got one of them on me school card:p

i cant do mot's but if you leave the car with me i can get that arranged with the other garage in the estate

ps i didnt tell you how much i hate brake fluid did i

[10:45PM]

Re: Soft brakes and spongy feel... FIXED BY McSMARTS!

i cant do mot's

Why, too difficult ?

ps i didnt tell you how much i hate brake fluid did i

that's only cos you're scottish and you can't bear not being able to re-use old stuff ? Och Aye

[Sam]

Re: Soft brakes and spongy feel... FIXED BY McSMARTS!

Why, too difficult ?



that's only cos you're scottish and you can't bear not being able to re-use old stuff ? Och Aye

aye far to difficult , or the fact if i did mot's i need to do them for all cars your not allowed to pick and chose, and i run a smart garage :p

i hate it caus the mess it makes, i like me garage clean as i can:redface:

[NeuroBeaker]

Re: Soft brakes and spongy feel... FIXED BY McSMARTS!

thanks been a while since i got one of them on me school card:p

i cant do mot's but if you leave the car with me i can get that arranged with the other garage in the estate

ps i didnt tell you how much i hate brake fluid did i

aye far to difficult , or the fact if i did mot's i need to do them for all cars your not allowed to pick and chose, and i run a smart garage :p

i hate it caus the mess it makes, i like me garage clean as i can:redface:

OK, sounds good - I'll be in touch a little later this month about getting that booked in... maybe get the service done in the same visit.

Sorry about the brake fluid Sam, but at least you've now gotten that out the way on our ForTwo for a while.

All the best,
Andrew and Nicky.