Hi everyone

I have no air in the system

I get a rock hard pedal when I screw a bolt into the master cylinder outlet


If I pump the pedal shallow I get sort of a pedal, but then if I push it hard and release it I lose everything. Once I release it I get kinda a bubbling leaking type noise as though its sucking air in at a connection but its from within the MC.

I rebuilt it myself.

In my totally unproffesional opinion I think theres a valve inside the MC wrong but I cant recall anything as such while putting a seal in it.

The fact that I "can" get a rock hard pedal makes me think that the overall condition of the thing is ok and its just something simple..


I can get a reco change over one for $88, but if the bores ok which I think it is I will just try and fix it.

any ideas"?

ty

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It's hard to go past the MC if there really is a bubbling noise from within...

Are you sure (if the bores are fine) that you didn't install a seal upside down?

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

I really woudnt know mate, its not a big deal I think I will just pull it off and have a geez

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There is a small plastic valve piece that goes in the top part of the bore before you put the spring back in, is that in there? There isnt one in the clutch MC only in the brake MC

I will check it out today thanks guys

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Ok I have checked everything, even went as far as having the MC checked by a brake guy.

I drip bled it some more and its still not bringing up a pedal.

I clamped the flex hose on the pass side and the pedal instantly improved. I took it off and the pedal feel returned to its normal shitty self.

I clamped the drivers side hose and it improved again.

I put seals in the calipers myself, they are not leaking so I would assume they are ok and I didnt stuff anything up.

The only thing I didnt change was the pads, they were a bit worn but I was just going to use em to break everything in.

my question,

could second hand rotors and worn pads be enough to cause all these problems?

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What Master cylinder is it?
Where is the proprtioning valve? Bulk head or rear sub frame
did you adjust and bleed the the rears as well?? It sounds like there is still air in the system, gravity bleeding will get rid on most of the fluid but not all.
Person 1 (in the car) pumps pedal, then takes foot off pedal
Person 2 cracks/opens bleed nipple
Person 1 then pushes pedal to floor (eg: emergency braking) and holds to floor
Person 2 then locks up bleed nipple
Person 1 then pumps pedal 'till firm again
Repeat process 3 - 4 times each corner, I start at the furthest point from master cylinder and work forward (l/r, r/r, l/f, r/f)

Hope this helps

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http://www.youtube.com/watch?v=nDMkVq1jRGU

its a standard MS

I the proport..... valve is at the rear. I have replaced the rear wheel cylinders with appropriate ones for disc brakes.

I have bleed the rears over heaps aswell.


I will try the preasure method

thanks mate.

the only other thing I was thinking is that maybe the pistons in the calipers are stuck at the bottom

I will keep digging

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as it turns out there was air in the caliper and no amount of conventional bleeding would get it out.

So basically I unbolted the caliper from the hub and then opened the bleed valve While the valve was opened I just moved the caliper around and upside down untill all the bubbles stopped coming out... took 5mins each side



easy peasy

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I hope you have the bleed nipples at the top....

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

what ya mean doc? the bleed nipples face downward

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oh no thats ****.

does it matter that they are on back to front?

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do u have a booster on the car?

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oil leak?..what oil leak..that puddle under the car is just sweat from all that horsepower

It doesn't matter, just makes them a pain in the arse to bleed

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Miniworx Centre 0883741299
Sooperdooperminicooperexpertengineering
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air will travel to the top of the caliper where the bleed nipple should be

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