First push of brake-pedal = hardly any stopping power

[bluetone]

Hello All,

On Friday I collected the car from a station car park after it had been sitting for a few <freezing> days. First push of the brake pedal = hardly any stopping power (nearly ran into the back of the car in front!), subsequent brake-use quickly restored stopping power. So I am thinking "maybe the calipers/pistons have been so wet/cold/iced-up the pistons froze-up somewhat", having never had this happen before.

This morning = same issue. Brakes fine after a couple of pushes of the pedal but the first one had my heart in my mouth...

The fluid level looks fine, I checked it yesterday. My guess is I have a seal letting-go somewhere?

Anyone else had this experience?

Cheers,
bt

[heebeegeetee]

I haven't experienced it, but it might be worth thinking about the age of your brake fluid and hoses. If you suspect they might be getting on a bit or you don't know how long they've been in/on your car, it might be worth thinking about renewing stuff.

Many people will advise all sorts of aftermarket stuff, but I can tell you that if you treat your car to a renewal of bog-standard stuff your brakes will be transformed.

You could splash out on new discs and pads as well as the above, and possibly re-seal the calipers, and then you'll have a car that'l stop on it's nose. But if money is tight new fluid and hoses will still make a huge difference.

[Howard-]

My guess is the pads are crap.

How does the pedal feel when you're doing this? I.e. is it any firmer/spongier at first/afterward?

[snotrag]

If its that the pedal feels 'soft' then the problem is with the hydraulics, IE could be old fluid that has taken on a lot of water or got some bubbles in, or could be the servo being a bit weak.


Whereas if the pedal feels right, but your just not stopping, then its the pads and/or discs.

If mine sits for a few days the discs (i think they must be cheapo parts) get awful rusty, and it requires a good few shoves on the brakes as i leave my street before they come back good.

[Pete Franklin]

yep as above i would say its just the discs rusting over. pretty standard situation- you just need to make sure they get cleared before you need to use the brakes in anger.

[dylan0451]

i'd say, if the brakes are continually naff first press every morning, but work just as well after as normal then it's disc corrosion, if the effort and/or travel has changed then i'd think either air leak to the servo/servo diaphragm has split or loss of hydraulic pressure. Mind, you say the fluid level hasn't moved so a leak sounds unlikely...

[bluetone]

Thanks for the feedback guys; all was fine this a.m. - go figure.

Anyway; I put new disks/pads on the front about 6 months a go.
But the rears are indeed shiiite; I have a set of rear disks that have been waiting for a decent weekends weather for me to fit.

I'll bleed the whole system at the same time.

Cheers.
bt

[bluetone]

And in answer to the questions above - the pedal felt pretty soft first-push.

Maybe the hideous damp and cold of recent months has resulted in some moisture getting into the brake fluid?

[heebeegeetee]

It's worth changing the fluid. I reckon you might be amazed at the difference it'll make.

[bluetone]

heebeegeetee said:

It's worth changing the fluid. I reckon you might be amazed at the difference it'll make.

Agreed that's a no-brainer, even though the fluid has only been in there about 6 months..

[heebeegeetee]

bluetone said:

heebeegeetee said:

It's worth changing the fluid. I reckon you might be amazed at the difference it'll make.

Agreed that's a no-brainer, even though the fluid has only been in there about 6 months..

Oh, what, new fluid throughout, not just a bleed?

Hmm. Might be worth rebleeding again then, but if you've done fluid, pads and discs in the past 6 months then something else is wrong.

How old are the hoses?

I wouldn't expect to have any issues with a car that has just stood overnight.

[bluetone]

heebeegeetee said:

Hmm. Might be worth rebleeding again then, but if you've done fluid, pads and discs in the past 6 months then something else is wrong.

How old are the hoses?

I wouldn't expect to have any issues with a car that has just stood overnight.

As above post, rears are well overdue replacement...hoses are original AFAIK..

[Gad-Westy]

Ours has/had a similar problem where the brake pedal would be rock solid first push and you'd have to really shove the pedal to get any stopping power. Feels like something is sticking and first became apparent in freezing wheather. I intend to keep an eye on it but am wondering if the piston seal on the M/C is breaking up.

[dylan0451]

a quick way to test the servo so as to rule that out is,

turn engine off, pump brake pedal a good few times until it goes hard, then while keeping pressure on the pedal, start the car. you should feel the brake pedal go down further.