Braking in the wet

[Guest]

If you don' t drive in the rain there is no need to read further.

When driving about in the rain, in particular where you are following other vehicles, such as on the M3, I have noticed that the feel of the brakes changes significantly.

When you press the pedal the same amount as you would in the dry, there is a lot less braking effect.
You need to stand on the pedal quite hard to get them to work.
Although when you do stand on them, they work well. It is just that the pedal travel is much more.
I assume that this is since the air ducts are directing spray onto the dics, or they are getting wet some other way.

I have never noticed this on other cars before.

In the dry, and after the wet spell, they work fine, so it is not sue to any wear or setup problem. In the dry they work better once you have braked hard a couple of times and warmed them a little.

Has anyone else noticed this wet weather behaviour? It is a little off-putting, but I guess I just need to get used to it.

I wondered if the ceramic brakes do the same, but I doubt anyone will know.

 

[ianbanneville]

I get this after washing my 4S (when the discs are waterlogged) but have never noticed it on the road.

It was an horrendous problem on my S1 Elise (no spray guards on the aluminium discs); I used to get into the habit of brushing the brake pedal every so often to clear off the film of water.

Regards

Ian

 

[Guest]

I don' t notice any difference after washing, but then they are dry by the time I finish messing about. The small amount of rust on them makes a difference the first time you brake, but one good stomp on the pedal and its all gone.

I keep a larger gap in the wet anyway, since regardless of the brakes the tyres don' t grip as well so you can' t brake as hard. Plus visibility is not as good and keeping back keeps you out of the spray and allows more reaction time.

It is just that having allowed a larger gap, the benefit is negated if when you press the pedal nothing much happens.
My previous car had 4-pot callipers and vented (but not drilled) discs and rain made no difference. It was perhaps over-servoed and pedal travel was small, but nonetheless the feel was the same.

Given the better ducting, I could expect to notice some difference, but it is much larger than I expected. I have observed it on 4 occaisions, so I know I am not imagining it. In slow moving traffic or after a few heavy brakings, it is OK since the water does not get to them or the heat has temporarily dried them out. it is just after following traffic along the motorway for a few miles, that come to brake you have to press twice as hard for the same effect. (Any residual heat has been lost in that time.)

If it is normal operation, then I will have to get used to it.

 

[Mark_Bennett]

That' s really odd.

I can' t say I have ever noticed this happening in my Boxster S - which has the same basic discs and calipers.

???

 

[Guest]

That' s why I wondered if others had noticed it. If not then perhaps there is some shield which is mislplaced, or the ducting is wrong, or there is some other assembly issue.

I' m going to ask the OPC anyway.

 

[Grant]

Personally I think it is a heat thing, the brakes on all the 996' s I have driven seem terrible untill they have warmed up a bit. The first time I apply the brakes each day I always note how poor they are (as in needing a VERY firm push to slow down), once a few applications have been applied & there is heat in them the car stands on it' s nose wet or dry !!