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Clutch Master Cylinder leak
Posted: 07 Mar 2008, 12:45
by tosh
mot is due soon and i've had a small drip from the master cylinder last 6mths, anyone know if the mot guy will fail it if he sees a brake/clutch fluid drip, its coming from the piston thing thats inside the rubber gaiter
Re: Clutch Master Cylinder leak
Posted: 07 Mar 2008, 13:10
by Ian Hulley
tosh wrote:mot is due soon and i've had a small drip from the master cylinder last 6mths, anyone know if the mot guy will fail it if he sees a brake/clutch fluid drip, its coming from the piston thing thats inside the rubber gaiter

GET IT FIXED ... sod the MOT man ... if that fails you could have a very unpleasant accident as said elsewhere it shares the hydraulic system with the brakes !!
Ian.
Posted: 07 Mar 2008, 13:12
by ermie571
if that fails
shouldn't that read....."when that really fails" as it has already failed....it is leaking!
Emma
x
Posted: 07 Mar 2008, 13:19
by Ian Hulley
ermie571 wrote: if that fails
shouldn't that read....."when that really fails" as it has already failed....it is leaking!
Emma
x
Emm, I was trying to give the guy the benefit of the doubt .... I'm calling it 'failing' at the moment .... not CATASTROPHICALLY failed, lost all clutch and within a few seconds all the brake fluid and brakes and crashed into a bus queue. And wound up in jail for driving a dangerous vehicle .
Ian.
Re: Clutch Master Cylinder leak
Posted: 07 Mar 2008, 13:22
by Grun
Ian Hulley wrote,
if that fails you could have a very unpleasant accident as said elsewhere it shares the hydraulic system with the brakes !!
Not so Ian, the reservoir is divided internally into two compartments, one for the brakes and one for the clutch. So in effect you have two separate reservoirs sharing a single filler orifice.
Loss of clutch fluid will not lead to brake failure from loss of brake fluid.
You are unintentionally giving folks a fright.
Mike
Clutch Master Cylinder leak
Posted: 07 Mar 2008, 13:31
by jonno
I would recommend you replace it if its leaking.
Its not very expensive or difficult to do.
Re: Clutch Master Cylinder leak
Posted: 07 Mar 2008, 13:32
by Ian Hulley
Grun wrote: You are unintentionally giving folks a fright.
Mike
In which case I apologise .... just please ask him not to drive near my family ... continually driving with a leaking clutch cylinder !
I thought the fluid loss from one affected the other

Strange that I topped our's up from the same reservoir then.
Ian.
Re: Clutch Master Cylinder leak
Posted: 07 Mar 2008, 14:05
by Blue Thunder
Grun wrote:Ian Hulley wrote,
Not so Ian, the reservoir is divided internally into two compartments, one for the brakes and one for the clutch. So in effect you have two separate reservoirs sharing a single filler orifice.
Loss of clutch fluid will not lead to brake failure from loss of brake fluid.
Mike
Is this really true? I filled my reservoir to the brim (way above the max mark) and drove with the leaking cylinder for about a mile. Checked the reservoir after this and it had gone down slightly. How is the reservoir split? Can't be a vertical split or I would have noticed two separate levels of fluid. I'm confused

Posted: 07 Mar 2008, 14:09
by Mocki
its a single res from which both systems draw, its isnt split internally, well ive never seen one that is....
if you are loosing fluid, fix it, as ap... you'll be a long time stopping one of these with your foot on the wheel, and a long time dead!
Posted: 07 Mar 2008, 14:15
by tosh
Its loosing a thimble every couple of months (nothing really) and it is separate from the brakes (2 reservoirs in one) I maybe wrong but i thought they just weep from the piston so it can't really just suddenly empty the clucth reservoir in seconds.
Also, yeah i do intend to fix it, looks straight forward, its just the bleeding of the clutch thats stopping me as i've read here some ppl can never quite get it right and i can't afford a mechanic at the moment.
Then theres the slave cylinder that can blow soon after fitting a new master and that can be a bugger too.
Has anyone heard of them passing with a weep as it is quite a common problem.
Re: Clutch Master Cylinder leak
Posted: 07 Mar 2008, 14:17
by Ian Hulley
Grun wrote: You are unintentionally giving folks a fright.
Actually it was quite intentional (deservedly so) and as it transpires correctly.
Ian.
Posted: 07 Mar 2008, 14:28
by Mocki
to answer the original question, its unlikely the mot man will see it, no one will be pressing the peddle while hes snouting about under there, and they have never lifted my engine lid for a mot, there is nothing in there that they need be looking at.......
Posted: 07 Mar 2008, 14:29
by T'Onion
My clutch master cylinder began leaking in France last year , we drove home ,via Cornwall and at the RTTH07 about 1500 then it just gave up , lost the clutch.
Now back to the brake debate , the clutch master cylinder is lower than the reservoir and lower than the Master cylinder , so any leak in the CMS would cause the res. to drain ,now if this would cause you to lose all braking is a debate that i wouldn't like to argue , no fluid , no vacuum , no vacuum no pressure , no pressure .....no

Posted: 07 Mar 2008, 14:31
by T'Onion
Mocki wrote:to answer the original question, its unlikely the mot man will see it, no one will be pressing the peddle while hes snouting about under there, and they have never lifted my engine lid for a mot, there is nothing in there that they need be looking at.......
but the res. is in the cab

Posted: 07 Mar 2008, 14:32
by clartsonly
in gruns defence as also added in the clutch thread, the resoviour feeds the clutch with the first inch or so of brake fluid, below that level the clutch will not work, so basically if your brakes are failing, you are likely to realise when you have no clutch, if your clutch is failing, once it has failed no more fluid is lost.
it is this shape of the reseviour
------
~~~@ pipe to clutch
~~~
~~~
@
pipe to brakes