Brake Problem, bit more help needed please..

[Pal318is]

Hi Guys,

The brakes on my iS have all of a sudden just gone soft, when i press the pedal. The brakes do still work, but I have to pump the pedal in order for them to work.

Any ideas what this issue could be? Any help will be much appreciated.

Thanks

[maxfield]

Burst brake pipe/hose? Master cylinder?

Have you checked the fluid?

[Grrrmachine]

Poor condition fluid, bulging rubber hose somewhere, porous hard lines letting air in, broken vacuum seal in the servo or air supply to it, or leaking master cylinder seal. Any of those, really.

[jimbom30cab]

yer, i'd start with checking the resevoir level then have a good look for leaks on the pipes or calipers

[Pal318is]

Thanks for all the replies guys, appreciate it

[Pal318is]

Going to check fluid level now.

[Pal318is]

The fluid level has dropped. Looks like I have a leak somewhere

[votivequagmire]

If it hasn't been checked for a while then it could simply be that the brakes have worn and the level has dropped. Unless of course it is completely empty, in which case yes you do have a leak.

[Pal318is]

I recently replaced my front brake pads, so its defo not the brakes.
I'm just hoping that weather stays ok here today been pissing it down for a few days!

[Pal318is]

Right, after some investigation. It looks like the leak is coming from where the resoviour joins the servo. Has anyone seen this before? Is it the resoviour that needs replacing or the actual servo? Or even both. The leak seems to be coming literally from where the two items join.

Any help would be greatly appreciated.

Thanks

[Pal318is]

Before I forget. The pedal does seem to intermittently go hard and then soft. It's like it's trying to hold pressure.

[Pal318is]

Just having a look through the wiki and I'm now ticking it could be the internal master cylinder or the seal, between the resoviour and servo. It's definitely coming from that area.

[Motorhole]

You mean around item 2 on the pic below?




May be perished seals in the master cylinder allowing fluid to be forced past those bungs as they arn't a pressure seal.

[Pal318is]

It looks like the master cylinder maybe fubar'd, as the leak looks like it's coming from the rubber bungs. Can these be replaced at all?
Thanks for the replies

[Pal318is]

Is there a kit available to overhaul the master cylinder or is it just better to get another one. Thanks for all the help.

[Grrrmachine]

It'd be a hell of a lot easier to get a decent replacement. I expect a rebuild kit will be the same price, if you can even find one.

[Pal318is]

Good point, will try and source a decent secondhand one if needed. Many thanks for all the help

[maxfield]

I highly doubt you'll get a seal kit.

I'm sure your local motor factors will supply you a new master cylinder at a good price.

I wouldn't put a second hand one on.