"Dripping" noise from brake master cylinder... but no leak?!

Samwell · Mar 25th, 2013, 23:07

So after finding a warning light flash up on the dash this morning, getting great help from Gatos suggesting the brake/clutch reservoir was low, topping up the fluid with Dot4 and testing it out, yes the light has gone off and stayed off. The level was low, beyond the clutch minimum level. But now Ive got another problem which is the probable cause for the level being low.

When I press and hold the brake pedal in, whether the cars started or not, under pressure it sinks to the floor after 30-60 seconds. Whilst driving, the car stops before I put anywhere near that sort of excessive force onto the pedal, but I dont go hard on the brakes and should i need to stop on a hill at some lights or in traffic, I wouldnt expect to be stood still for much more than a minute (depending on gradient of course!) Its not deadly at the moment, far from it, but it probably would pass an MOT with a thorough inspection and I do worry that it could get worse quickly when I need it the most.

Right now, I press the pedal and the fluid drops a few millimetres if I take it to the floor. I put my head inside the footwell and I hear a "dripping" noise every 1.5 seconds, becoming faster with more pressure. BUT I cannot see any leaks whatsoever from inside the engine bay, master cylinder, brake hoses/pipes, calipers or from the footwell area. Its really odd! Unless the firewall is hollow inside?? Theres no fluid underneath the car anywhere.

Luckily the brakes were only replaced a good 3ish months ago (before I bought it) and work REALLY well so stopping isnt an issue. What concerns me most is that the fluid MUST be dissapearing somewhere, right?? OR would the faulty seal in the master cylinder cause that?

I did find a post on here started by Gatos who found this on someone else's car, but it wasnt clear of the outcome. Any thoughts would be so greatly appreciated!

Dog_Book · Mar 26th, 2013, 09:00

Dangerous, don't drive it get it repaired.

Samwell · Mar 26th, 2013, 09:53

My thoughts exactly. Brakes are something I wouldnt want to skimp out on.

Ive spoken to an engineer I work with who replaces many master cylinders in machines, he says that its probably the seal inside out or a bad bleed has been performed in the past which might have left a pinhole in the master cylinder seal from grit or something like that. Might be leaking into the servo unit, which is why I havent seen any oil.

Volvon · Mar 26th, 2013, 13:49

Dripping sound is weird indeed, Take it to a mechanic.

volpete · Mar 26th, 2013, 19:29

Hi there samwell check underneath carpets in front of drivers seat it could be disappearing underneath them as just above there is where the master cylinder
is had this a few years ago on a car I owned not a volvo but just a thought.either that or it could be going in the servo under bonnet.
Volpete

Samwell · Mar 26th, 2013, 20:34

Thanks Volpete... i had wondered what a damp patch in the middle of my floormat was doing there. I had been wondering if that was my missing fluid... but i just took the mat out, the carpets a bit damp underneath but not excessive. I took the floor carpet up a bit and put my hand between it and the metal floorpan, but its dry. Its all dry around the inside of the car too so Im thinking its leaking into the servo. Question is, does that mean a new servo unit too or can it be drained??

Just to add as well, since this has become apparent, ive got a odd clicky noise happening from within the dash itself, seems to be movement related... but annoying.

keithyboy · Mar 26th, 2013, 21:13

The pedal creep sounds like a shot master cylinder. Normally if it leaks the fluid runs down the front of the servo. Sometimes, they don't actually leak at all. I recall a Ford Orion I had years ago where the cylinder packed up completely but it didn't leak a drop.

billyloadsamud · Mar 26th, 2013, 21:27

Undo the bolts/nuts holding master cylinder to servo and ease master cylinder forward, don't undo brake pipes, (can be moved enough to look into servo ) check for fluid inside servo.
DOES sound like seals have gone and as an MOT tester it would fail as pedal creeps to floor under pressure and I would mark it as DANGEROUS.

twilightflyer · Mar 26th, 2013, 22:16

Check out this You might find it useful.

http://www.volvoforums.org.uk/showthread.php?t=99123

Samwell · Mar 26th, 2013, 22:56

That is a VERY helpful post!!! Thank you! I will go out and check now. I might mention to the mechanic it might be worth him replacing the servo as well... there is some rust in places you wouldnt imagine on a 2004!

Mar 25th, 2013, 23:07	#1
Samwell Master Member Last Online: Oct 22nd, 2019 15:49 Join Date: Jan 2013 Location: Strängnäs, Sweden	"Dripping" noise from brake master cylinder... but no leak?! So after finding a warning light flash up on the dash this morning, getting great help from Gatos suggesting the brake/clutch reservoir was low, topping up the fluid with Dot4 and testing it out, yes the light has gone off and stayed off. The level was low, beyond the clutch minimum level. But now Ive got another problem which is the probable cause for the level being low. When I press and hold the brake pedal in, whether the cars started or not, under pressure it sinks to the floor after 30-60 seconds. Whilst driving, the car stops before I put anywhere near that sort of excessive force onto the pedal, but I dont go hard on the brakes and should i need to stop on a hill at some lights or in traffic, I wouldnt expect to be stood still for much more than a minute (depending on gradient of course!) Its not deadly at the moment, far from it, but it probably would pass an MOT with a thorough inspection and I do worry that it could get worse quickly when I need it the most. Right now, I press the pedal and the fluid drops a few millimetres if I take it to the floor. I put my head inside the footwell and I hear a "dripping" noise every 1.5 seconds, becoming faster with more pressure. BUT I cannot see any leaks whatsoever from inside the engine bay, master cylinder, brake hoses/pipes, calipers or from the footwell area. Its really odd! Unless the firewall is hollow inside?? Theres no fluid underneath the car anywhere. Luckily the brakes were only replaced a good 3ish months ago (before I bought it) and work REALLY well so stopping isnt an issue. What concerns me most is that the fluid MUST be dissapearing somewhere, right?? OR would the faulty seal in the master cylinder cause that? I did find a post on here started by Gatos who found this on someone else's car, but it wasnt clear of the outcome. Any thoughts would be so greatly appreciated!

Mar 26th, 2013, 09:00	#2
Dog_Book Idiot Last Online: Apr 21st, 2019 17:29 Join Date: Nov 2006 Location: Derby	Dangerous, don't drive it get it repaired. __________________ Vectra VXR estate convert Experience = V40 1998 2.0 CD lots of mods Busy pestering the poor sods here now

Mar 26th, 2013, 13:49	#4
Volvon Master Member Last Online: Nov 13th, 2020 06:29 Join Date: Mar 2010 Location: The Land of Ice & Snow	Dripping sound is weird indeed, Take it to a mechanic. __________________ 1999 V40 1.9D (D4192T2 engine) Current mileage: 211,000 miles Average MPG: 54.4

Mar 26th, 2013, 19:29	#5
volpete volpete Last Online: Mar 12th, 2015 14:56 Join Date: Nov 2010 Location: romford	dripping from brakes Hi there samwell check underneath carpets in front of drivers seat it could be disappearing underneath them as just above there is where the master cylinder is had this a few years ago on a car I owned not a volvo but just a thought.either that or it could be going in the servo under bonnet. Volpete Last edited by volpete; Mar 26th, 2013 at 19:32.

Mar 26th, 2013, 21:13	#7
keithyboy Master Member Last Online: Jul 19th, 2015 20:48 Join Date: Dec 2007 Location: Bolton	The pedal creep sounds like a shot master cylinder. Normally if it leaks the fluid runs down the front of the servo. Sometimes, they don't actually leak at all. I recall a Ford Orion I had years ago where the cylinder packed up completely but it didn't leak a drop. __________________ My blog ^^^^^^^^^^^^^^^^^ LOOK AT MY RUBBISH BLOG

Mar 26th, 2013, 09:53	#3
Samwell Master Member Last Online: Oct 22nd, 2019 15:49 Join Date: Jan 2013 Location: Strängnäs, Sweden	My thoughts exactly. Brakes are something I wouldnt want to skimp out on. Ive spoken to an engineer I work with who replaces many master cylinders in machines, he says that its probably the seal inside out or a bad bleed has been performed in the past which might have left a pinhole in the master cylinder seal from grit or something like that. Might be leaking into the servo unit, which is why I havent seen any oil.

Mar 26th, 2013, 20:34	#6
Samwell Master Member Last Online: Oct 22nd, 2019 15:49 Join Date: Jan 2013 Location: Strängnäs, Sweden	Thanks Volpete... i had wondered what a damp patch in the middle of my floormat was doing there. I had been wondering if that was my missing fluid... but i just took the mat out, the carpets a bit damp underneath but not excessive. I took the floor carpet up a bit and put my hand between it and the metal floorpan, but its dry. Its all dry around the inside of the car too so Im thinking its leaking into the servo. Question is, does that mean a new servo unit too or can it be drained?? Just to add as well, since this has become apparent, ive got a odd clicky noise happening from within the dash itself, seems to be movement related... but annoying.

Mar 26th, 2013, 21:27	#8
billyloadsamud Junior Member Last Online: May 5th, 2013 21:14 Join Date: Jan 2013 Location: near; brighton	Undo the bolts/nuts holding master cylinder to servo and ease master cylinder forward, don't undo brake pipes, (can be moved enough to look into servo ) check for fluid inside servo. DOES sound like seals have gone and as an MOT tester it would fail as pedal creeps to floor under pressure and I would mark it as DANGEROUS.

Mar 26th, 2013, 22:16	#9
twilightflyer Senior Member Last Online: Jul 16th, 2023 11:37 Join Date: Sep 2008 Location: East Yorkshire	Check out this You might find it useful. http://www.volvoforums.org.uk/showthread.php?t=99123

Mar 26th, 2013, 22:56	#10
Samwell Master Member Last Online: Oct 22nd, 2019 15:49 Join Date: Jan 2013 Location: Strängnäs, Sweden	That is a VERY helpful post!!! Thank you! I will go out and check now. I might mention to the mechanic it might be worth him replacing the servo as well... there is some rust in places you wouldnt imagine on a 2004!

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