Which fluid dripping?

[xsara92]

I have a slow leak at the front of a Xsara Picasso. At first I thought diesel, but it seems to be a more viscous substance. It smells like an oil, but a bit pungent. However appearance wise it is a clear, straw colour.
Is this more likely oil or could it be power steering fluid or coolant?

[Muir]

If it smells strongly and somewhat gassy it might be brake fluid.

[CitroJim]

That would be my thought too and if it is, needs to be checked and the problem resolved soonest.

Do these have hydraulic clutches? It may be that leaking rather then brakes...

[xantia_v6]

Depending on the type of transmission, it could also be transmission oil/fluid.

[xsara92]

It does have (quite) a strong smell, but I wouldn't go as far as to call it eggy or fishy...
There's a slightly milky residue left on the ground.


Yes CitroJim these are hydraulic clutches (manual). I just had this one replaced along with the flywheel. It took the garage 12 hours of labour time
On my invoice, both clutch fluid and transmission oil are listed.
I'm learned in all these areas, though my Haynes manual does say that when the clutch fluid is renewed, "allowance should be made for the old fluid to be expelled when bleeding a section of the circuit" . So sounds like old fluid is supposed to come out at some stage in the renewal process?
Also, it looks like the fluid reservoir is around mid-way, though I find it really difficult to tell as the plastic is quite opaque and there is a clear plastic diaphragm over the spout, which presumably has a pinhole to enable filling, though I've not yet tried topping up - should be my next port of call, I guess.

[Muir]

Well if the fluid cause friction when rubbed between two fingers it's most likely brake/clutch fluid - it's somewhat abrasive.
If it feels more like thin engine oil and slippery between your fingers it probably transmission oil or steering fluid.

Maybe they didn't tighten up the bleeder valve for the clutch properly.
It's usually situated right on top of the clutch bell housing where the pipe goes into the actual housing.

[PaulC5]

I have yet to see a clear plastic diaphragm on the brake fluid reservoir spout when the cap has been undone but only a strainer at the bottom of the spout. Possibly somebody has fit the plastic to reduce fluid loss when changing part of the brakes or clutch master/slave cylinder - or the cap is coming apart. Brake fluid is water soluble and when mixed with water (rain) can go milky so if the drips are under the car in the area of the front of the gear box then it might be brake fluid. It is also easy to wash off your fingers, unlike oil. To better see the level in the brake fluid reservoir a torch held against the side of it can help.

[xsara92]

Thanks Muir, I would say it's a thin substance. The drip is coming from the RHS as you face the car head-on.

[xsara92]

Rereading the above two posts, the bleed screw does look like a possibility! On the Xsara P it looks like I can reach under the radiator at the front to tighten it without a tool. If/when I'm feeling brave..

Unfortunately, my rear brake which wasn't binding successfully on the MOT, is now excessively binding and affecting the car significantly on sharp acceleration (pulling back/to the opposite site on a turn e.g when leaving a roundabout).
Is there any possibility a binding brake could lead to the ejection of fluid through pressure build-up?

[xantia_v6]

This sounds rather strange. The rear brakes and suspension are not really connected to sharp acceleration. Any pulling to one side is more likely due to something broken or worn in the front suspension, probably lower arm bushes or ball joints.

[Muir]

By binding you mean braking/engaging right?
If your brake is now sticking that might suggest there's water in the brake fluid which can cause it to boil & expand when it gets hot enough.
I don't think theres usually any kind of pressure valve in the brake fluid cover since the fluid is designed specifically withstand temperatures where other fluids boil.

If it's diluted enough it might expand during braking and cause constant pressure in the brake lines.
Does it happen right from where you start driving (cold car) or only after driving for a bit?

[PaulC5]

Anything to do with the brakes should not affect the clutch slave cylinder if this is where brake fluid is leaking out and if it is brake fluid. If it is brake fluid leaking from the slave cylinder, make sure you keep the reservoir topped up since the take off for the clutch is higher than for the brakes and if the level drops you can end up with air in the clutch master/slave cylinders and then the clutch will not work well until the air is bled out.

[xsara92]

Hi Muir, yes the problem shows itself when the car has been driven for a good 20-30 mins. I mean engaging.
How could I have ended up with water in the brake fluid? I don't immediately see how.
The other thing I forgot to mention is that my handbrake needs adjustment, which could also be a cause of the brake binding.
I haven't yet been able to get brake fluid PaulC5

[PaulC5]

Brake fluid gradually absorbs water from the atmosphere which reduces its boiling point, hence why it is replaced every 2 years.
The handbrake should only be adjusted once the rear brakes are sorted, otherwise the self adjustment of the rear brakes will not work properly.

[Muir]

Well what could be happening is this, and it's *just* a guess.
Your handbrake is causing your rear brake to drag a little, heating up the brake fluid after driving a bit.
This in turn can cause the whole brake system to become pressurerized if your fluid is old and sufficiently diluted with water (from whereever it might be coming from).
Try pulling over after 30+ min by rolling to a stop/braking very gently and gauge the temperature of your brake disc vs. each other - are some much hotter than others?

Again the above is just guesswork and I might be thinking waay outside the box here. But any issue to do with brakes really should get sorted asap, especially if it results in brakes not working proper.