S60 Brakes: How much fluid would clutch master cylinder leak?

[ilmiont]

Originally Posted by S60D5-185

My car had 56k on the clock when it failed.😢

Mine's about to hit 130k and nothing in the (incomplete) history to confirm the CSC has been done. Bracing myself for an even bigger bill than anticipated...

I have a question though about the reservoir - I read that although it's a combined reservoir for clutch and brake, it is partitioned inside so that a critical fault in one system shouldn't affect the other.

Now, excuse my lack of experience, for this may be a false assumption, but couldn't the fact that my clutch feels great but my brakes feel a bit soft then be an indication that the leak is within the brake system? Or has so much fluid been lost via the CSC that it's lowered the brakes side of the reservoir too?

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I've discovered from the history that the clutch position sensor was replaced with a new part in April 2017 and then again in July 2018! Both times it was taken in with a report of no cruise control... this was done by a Northamptonshire Volvo specialist which appears to be reputable and yet here we are again, no cruise control once more, looks like they have twice ignored the fluid that we know is leaking onto it and presumably not bothered to cover the sensor with anything!

My sensor then is approaching two years old, hoping I can pull it out and clean it still...

[Brendan W]

Originally Posted by ilmiont

I have a question though about the reservoir - I read that although it's a combined reservoir for clutch and brake, it is partitioned inside so that a critical fault in one system shouldn't affect the other.

Now, excuse my lack of experience, for this may be a false assumption, but couldn't the fact that my clutch feels great but my brakes feel a bit soft then be an indication that the leak is within the brake system? Or has so much fluid been lost via the CSC that it's lowered the brakes side of the reservoir too?

I would be checking the four wheels for signs of brake fluid leakage.
The car is a lot more worried about not being able to stop, brake fluid level, rather than being able to go, clutch fluid.

[S60D5-185]

Originally Posted by ilmiont

Mine's about to hit 130k and nothing in the (incomplete) history to confirm the CSC has been done. Bracing myself for an even bigger bill than anticipated...

I have a question though about the reservoir - I read that although it's a combined reservoir for clutch and brake, it is partitioned inside so that a critical fault in one system shouldn't affect the other.

Now, excuse my lack of experience, for this may be a false assumption, but couldn't the fact that my clutch feels great but my brakes feel a bit soft then be an indication that the leak is within the brake system? Or has so much fluid been lost via the CSC that it's lowered the brakes side of the reservoir too?.

My comment re the CSC was based on my own experience and is nothing more than a suggestion BUt, at the very least I would remove the tray and look at the bottom of the bell housing.

If it is the CSC at fault you should see fluid. Just rechecked and mine went at 62K not 56K. I asked the Volvo independent that I used and trust to fit a new clutch whilst the box was out. I got a call from him to say that he would change the clutch if I insisted but the existing one was uncontaminated and still perfect. He strongly advised against it. I agreed and sold the car with another 120 k on the clock ( also towing a caravan ) and the clutch was still perfect .

The fact that you mention brakes feel a bit spongy is well worth investigating exactly as Brendan W states in his last post. Good advice.

Check all the obvious as outlined by myself and Brendan and then you should hopefully be able to track it down.

Fingers crossed that it's the brakes as a leak there, although far more dangerous is far less expensive to remedy than the CSC.

Good luck and keep us informed.

It looks a nice car and should be worth sorting .👍

SEE HERE

https://www.volvoforums.org.uk/showt...linder+failure

[ilmiont]

Inspected the car again today.

Tricky to check the brake fluid level as it's clear fluid in a clean reservoir with awkward sun reflections and on a hill, but I'm not sure if the level has changed since the other day and there's certainly still some in there. This will be easier to tell once I get some new fluid in and I'll then mark the reservoir with a known level.

Started the car (no low brake fluid warning in the DIM) and pumped the clutch and brake pedals with an assistant looking underneath the car. No obvious visible leaks. Clutch feels good again, brake feels a bit spongy again; didn't move the car though so not sure really if the feel has changed since earlier in the week.

Noticed that the undertray seems to be absent which will at least be helpful in looking for things. (Interestingly the undertray being fitted was flagged as an MOT advisory a few years ago; I hope nobody took it off just to end up with no advisories on the next MOT... not sure how much a new one will cost but perhaps worth me considering.)

Anyway, here are some photos...

No. 1 - There appears to be a small patch under the centre of the car, could this be the CSC? Not observed it drip yet. (Suspect area highlighted in red.)



No. 2 (a/b/c) - This is what's on the road - I do not know for sure whether it is my car, or for that matter, that it isn't my car. Between Monday and Wednesday, my car was parked slightly (and only slightly) further forward and so it now seems distinctly possible that this has come from my nearside front wheel. I only noticed it when I got back Wednesday night, having had the low brake fluid warning, when I parked in the current position. This patch does not seem to have grown since Wednesday. It doesn't smell quite like oil so I do wonder whether this might be where my brake fluid has gone to - in which case I don't understand why it doesn't seem to be losing any more at the moment. But as I say, I can't confirm this is my car's loss... I suspect that if this is from my car, it would have been there Wednesday night before I took her out, but I didn't notice it, due to the location - although I did reverse into the current position so possibly it could have lost some while parking.







No. 3 - Nearside front again.



No. 4 - Offside front.



No. 5 - Nearside rear.



No. 6 - Offside rear.



No. 7 - From behind.



No. 8 - From offside - there seems to be something damp/fluidy at the back, fuel tank? Not sure if this is anything significant and seems unrelated to the brake fluid conundrum but providing an image anyway.



Thanks all for your time so far, at this point I know it's best to just take it in but I like to have an idea what's wrong first whenever possible! Brake fluid should be here on Monday; current plan is to put a little in so it's clearly visible, mark the reservoir, leave it a few days and see what happens to the level. Top it up again, drive her the 2 miles to the garage if it seems safe to do so.

Originally Posted by S60D5-185

It looks a nice car and should be worth sorting .👍

Thanks, I ended up paying only a little over £1,000, knowing full well though that it's going to cost that much again just on the faults I already knew about (having the CSC done would be quite a shock but I think I would go ahead with it).

My reasoning being that if I were to buy a facelift S60 2.5T SE in dream "perfect" condition, I think I'd be looking at upwards of £2,500, and it would still need things doing to it in time anyway - alarm, anti-skid etc., which I know could crop up at any point on any car.

Mine is in good condition generally just with a whole series of S60 faults happening at once. With a bit of initial expenditure, I hope to spend not a huge amount more than if I'd bought a "perfect" car to start with, with the benefit of knowing I've had lots of the common faults done and be good to take it to hopefully 200k and beyond without a huge amount more required. I hope - we'll see!

[Brendan W]

Brake fluid has a very distinctive fishy cat pee smell unlike engine oil.

[ilmiont]

An update... not what I expected.

ATE TYP200 arrived today. Went down to the car this evening. Nothing new visible on the ground.

Started pouring brake fluid into reservoir. To my surprise, it stopped going down into the reservoir from the intake almost immediately. It took a little perhaps but not much at all. Waited a couple of minutes and it did not go down.

So... it would appear that the combination of sunlight, awkward shadows, clear fluid in a hard-to-see-through reservoir, parking on a hill, the warning light and all that on the ground resulted in a premature misdiagnosis by myself. It would now appear that the fluid level is not - and has not been - anywhere near the MIN mark, thus what's on the ground cannot be from my car.

(After sniffing my new fluid and the stuff on the ground, I'm convinced it is brake fluid on the ground, but it would appear not from my car after all!)

Put cardboard under the car nonetheless so will confirm tomorrow whether anything comes out. Started engine, pumping brake and clutch repeatedly, nothing visibly leaking.

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So now the issue seems to be "the brake pedal is soft, but the reservoir is full."

The pedal still feels soft and spongy but gains pressure after several pumps. Releasing the pedal and then pressing again a few seconds later and it's back to being spongy. Is this just air in the system?

Will confirm tomorrow whether it's losing fluid, as will leave overnight with the cardboard, check for leaks in the morning and check the reservoir level again. If it stays as-is, I may have to draw some out with a syringe as it now seems to be almost too full (there's a pool of fluid in the intake under the cap).

Nothing 100% yet but the prognosis seems to be more positive. For the timebeing I'm chalking the warning message while driving down to a random sensor trip, and assuming there is somebody else in the area who has lost all their brake fluid onto the road...

Reservoir level - parked facing uphill; it now seems like all the dark on the left must be brake fluid... which looked invisible the other day

[ilmiont]

Checked the car this morning... cardboard dry, reservoir level unchanged.

Feeling a bit ridiculous now but that reservoir genuinely looked the same colour throughout and I couldn't see anything moving when I shaked it lightly last week. Combined with the mess on the ground and the "brake fluid low" DIM message, I feel like I had valid grounds to assume it had lost its fluid...

Anyway, it hasn't lost any substantial amount of brake fluid after all, the stuff on the ground can't be mine, and the DIM message... still a bit odd but I guess just a momentary bad sensor reading.

The fault now then is just that the brake pedal is soft, gains pressure when pumped, then loses it again.

[Brendan W]

Don't worry about feeling ridiculous. We have all been there, no exceptions.
Clean brake fluid is almost invisible from outside the reservoir. In fact if i can see the level from a few meters away, I check when I last replaced it.
With my optimistic hat on you have air in the system and it needs bleeding.
Was any work done on the system recently? Air would only tend to get in if the system was opened or there is a leak.

[barrybritcher]

if you have no history get someone to help you bleed the brakes the old fashioned way - it's free and should be done every 24 months max

[Willow place]

Just a quick question, it was mentioned about the Under tray , MOT Advisory ? does that mean it has to be removed for the test ?