Brake fluid leak

[mmisch]

Hello, since a few weeks i got a brake fluid leak somewhere and i since 2 days now i basically cant drive my car anymore since the clutch stays at the bottom.

here's a few keypoints on whats going on:

WITH THE CAR OFF:
clutch pedal works normally as it should, no problems

WITH THE CAR OFF AND NOT STARTED FOR A FEW HOURS:
brake fluid is not dropping when topping it up

WITH THE CAR OFF BUT HAS BEEN STARTED BEFORE:
When filling, the fluid doesnt drop?


WITH THE CAR ON:
If i depress the pedal for less than 10 seconds its it will return on its own
if i hold it longer for 10-20 seconds, the pedal with go halfway and wont come back, unless i put it back up manually
This issue happened to me also while driving, and when i hold it for 10/20 seconds, i cant also shift anymore, and the clutch biting point will be at the absolute lowest point
and the car tries to drive forward by itself with me having my clutch pedal in, but in the meantime the car also tries to stall, so the only solution for that is; turn the car off>manually put the clutch back up>i can shift again out of gear to neutral> start the car>drive away asap




other info:
- No wetness at master cylinder, bone dry
- after cleaning it all up, i found fluid drips on the bottom of the starter, a bit of wetness on the breather block thing (but that could be from me bleeding the clutch which did not help) and on the front of the gearbox itself, also a bit of drips on the ARB

I got a leon mk1 2005 1.8T AUQ, with a 02M FML 6 speed gearbox, and i better hope its not the slave cylinder since its CSC

If it is my slave cylinder leaking somehow i will get the clutch/pressure plate done too since the box is already out


here are some videos i took:

anyone got some things i could check or advice? thanks

 

[Connor H]

if you have brake fluid on the starter then it could be coming from the bleeder block and dripping down. I have had no end of issues with these stupid things myself. If you recently took it off or messed with it chances are it wont seal properly again.

First thing to try is get some brake cleaner or whatever and clean that whole bleeder block and area bone dry, as well as your starter. top the reservoir up, bleed it if you need, try use the clutch pedal and then check that area again after some use or a couple of days. You can just feel around the area with your hands and check for brake fluid. If its wet and sure its coming from there then you should:

Get a new bleeder block and the correct O ring and the other weird top hat shaped rubber seal. Get them from your local VAG dealer or somewhere that sells legit genuine stuff. Cheap seals and O rings will just send you back in there fixing the same issue. Even a slight leak of just air in this area will make you lose clutch pressure over time.

 

[mmisch]

Okay i will look at the breather block, i havent taken it off yet, since you need to bleed it again after removing, right?
I did try and bleed it but didn't help.

also i did some test today:

Basically:
1. I pressed the clutch for 20 seconds with the car off > nothing happens, the clutch works perfectly, as it should.

2. I started the car, had a cold start > held the clutch in for 10 seconds, and it go back to to halfway and stay there

3. I lowered the pedal (halfway) and turned the car off, then manually raised the pedal and pressed the clutch again for 10/20 seconds, nothing happened at all.

 

[mmisch]

Also, if the bleeder breather block was leaking, wouldnt it gave me also issues with the pedal when the car is off? Since my problem only happens when the engine is on

 

[mmisch]

Ive tried to clean the breather assy but then i felt it was very loose, is this normal??

 

[Connor H]

Ive tried to clean the breather assy but then i felt it was very loose, is this normal??

Yeah thats normal, wouldnt be too heavy handed with it personally well if its not leaking there then your issue is elsewhere.

With such inconsistent pedal i cant draw a pattern to where the issue might be. Its possible your slave cylinder is wearing out? its inside the gearbox. attached the bleeder block there.

Only thing i can suggest is you double check your reservoir, pipes, master cylinder, bleeder block and all associated piping.

 

[mmisch]

Yeah thats normal, wouldnt be too heavy handed with it personally well if its not leaking there then your issue is elsewhere.

With such inconsistent pedal i cant draw a pattern to where the issue might be. Its possible your slave cylinder is wearing out? its inside the gearbox. attached the bleeder block there.

Only thing i can suggest is you double check your reservoir, pipes, master cylinder, bleeder block and all associated piping.

Is that actually normal ? It seems quite alot of play, yeah i better not hope its the slave or else i'm gonna get a new clutch too.

Master cylinder dry, bleeder block wasn't dry (could be because of bleeding it and spilling some after removing hose?)
the only thing i am kinda confused about is that play at the breather, but you said its normal so i guess its okay?
Other pipes dry.

Where would it leak if it actually was the slave cylinder? I do have alot of gunk on the back side of the box, like behind the coolant flange, on the right side of the engine. There is a black rubber hole which is a inspection hole if i had to guess?

 

[Connor H]

Is that actually normal ? It seems quite alot of play, yeah i better not hope its the slave or else i'm gonna get a new clutch too.

Master cylinder dry, bleeder block wasn't dry (could be because of bleeding it and spilling some after removing hose?)
the only thing i am kinda confused about is that play at the breather, but you said its normal so i guess its okay?
Other pipes dry.

Where would it leak if it actually was the slave cylinder? I do have alot of gunk on the back side of the box, like behind the coolant flange, on the right side of the engine. There is a black rubber hole which is a inspection hole if i had to guess?

Yeah its normal to a degree, the bleeder block just floats there attached to its counterparts each end. Yeah the bleeder block would be wet after bleeding, its a messy task

If the slave is leaking you'd probably have fluid inside the bell housing, maybe leaking out right at the bottom of the gearbox somewhere i think. But ive not experienced that myself so not sure.

 

[mmisch]

Yeah its normal to a degree, the bleeder block just floats there attached to its counterparts each end. Yeah the bleeder block would be wet after bleeding, its a messy task

If the slave is leaking you'd probably have fluid inside the bell housing, maybe leaking out right at the bottom of the gearbox somewhere i think. But ive not experienced that myself so not sure.

If it actually was leaking from the bell housing, wouldnt it be more messy than it was? And more leaks/dripping?

I am still not sure if its maybe just a o ring or something, maybe from the bleeder block, maybe its leaking internally in the master cylinder but then it would be sticking when the car is off.. but it only happens when the car is on so its kinda strange..

 

[ExiledWeegie]

if it was the slave inside then it would find the lowest point to leak from, right at the bottom between the engine and gearbox.
its maybe not doing it when the car is off because you dont have servo assistance? which might point to the master cylinder? not 100% though.

 

[mmisch]

if it was the slave inside then it would find the lowest point to leak from, right at the bottom between the engine and gearbox.
its maybe not doing it when the car is off because you dont have servo assistance? which might point to the master cylinder? not 100% though.

Can i ask what you mean with servo assistance? Also, is there any way to (bench)test the the master cylinder? If i have to replace/open stuff like the breather or master cylinder then i would do that first since it won't cost as much as dropping the gearbox and clutch

 

[ExiledWeegie]

when the car is off you notice the brake pedal is hard, when you turn the car on it goes more spongy feeling because theres vacuum assisting the brakes. this happens in the brake servo (the big disc thing the master cylinder attaches to).

to test you might be able to unbolt the master cylinder from the servo unit and see if theres any brake fluid inside it? could be leaking past the seals and filling that up with fluid which might explain where its going.

dont know to be honest though, my money would still be on the slave in the bellhousing with your symptoms.

 

[mmisch]

when the car is off you notice the brake pedal is hard, when you turn the car on it goes more spongy feeling because theres vacuum assisting the brakes. this happens in the brake servo (the big disc thing the master cylinder attaches to).

to test you might be able to unbolt the master cylinder from the servo unit and see if theres any brake fluid inside it? could be leaking past the seals and filling that up with fluid which might explain where its going.

dont know to be honest though, my money would still be on the slave in the bellhousing with your symptoms.

Ohh the brake servo, yeah now i understand, thought you meant something different with servo assistance

Yeah well it could be worth checking i guess, since i even can't drive the car at this point, before i make an appointment with the garage for a clutch replacement.