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The car has done this since I've had it, but now I want to get it sorted.

Basically when braking and even when stationary and just pressing the brake pedal it comes to a very mechanical definite stop about half way down. Almost as if I'm against the floor, it's that sudden. It's not a sudden increase in resistance but an actual mechanical limit, or that's what it feels like.

So in the dry, I can stamp on the pedal, hit the 'stop' (it feels very mechanical, like I can feel two bodies making contact and through the pedal) and the front wheels aren't anywhere near locking and I can't physically exert more pressure

I've just changed by front calipers and front lines and re-bled the system again, and it's remained the same.

Time to pick up a brake master cylinder? The car is a Mk2 without ABS. I've Googled symptoms of a failed master cylinder and didn't come up with the above so thought i'd ask here before pulling the trigger.

EDIT: The fluid level isn't dropping, there's no leaks, nor does it loose pressure the longer I hold the pedal down.

Thanks all!

Ryan.
 

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Sounds like it's hitting the brake light switch. This is adjustable, lie upside down in the footwell and you will see it at the back of the pedal lever. You can also adjust the pedal height whilst you're down there.
 

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I see this which is what the brake pedal actuates, which can be adjusted (would I 'undo' this nut?). Aside from that I can't see anything which is limiting the pedals travel? Or have I missed something?



EDIT: I've just remembered when bleeding it went down to the floor, so am I right in thinking its got to be the master cylinder?
 

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I see this which is what the brake pedal actuates, which can be adjusted (would I 'undo' this nut?). Aside from that I can't see anything which is limiting the pedals travel? Or have I missed something?



EDIT: I've just remembered when bleeding it went down to the floor, so am I right in thinking its got to be the master cylinder?
I've a master cylinder/pedal setup spare you can try if you want....
 

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Discussion Starter · #6 ·
That's a very kind offer cheers!

Just to bump to the top to see if anyone can confirm:

When bleeding the brakes, the pedal will go all the way to the floor, however when the bleed nipple is tightened to induce more resistance, or fully tightened the pedal will only go half way down.

You know the feeling when you pump the brake with the engine off (no booster) and it gets harder and harder to pump the pedal and comes to a dead stop at the end of travel?
That's the feeling I have with the engine running but consistently halfway down the pedal travel.
 

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No vacuum assist.

If a nipples just cracked open a little, when you hit the stop and continue to lean on it is the only time it sinks
 

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To be honest I have been having a wtf moment every time you have posted. I have never had one to bits. Without assistance though the pads all move in to place with relative ease compaired to then trying to squeeze them. There is just nothing to 'give' except expanding your hoses. The effect would be like you describe. You have a degree of brake modulation as they shift in to place almost in turn. Then you have a bit more give as all the brackets square up. Then you hit a wall.

The same experience comes from trying to drive a car without the engine running. Like towing. Perhaps people can relate to that better. I'm sure there have been pleanty of wtf's over this one lol
 

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Discussion Starter · #10 ·
Yeah same, it is so strange. (Thanks for the replies btw).

The thing is though I can pretty much get the fronts to lock up in the wet, so still plenty of braking effort.

It's like at the halfway down position the pressure required is too great and the faulty servo gives way.

It is strange, with the engine on I pump the brake it consistently goes down to that same level, turn the engine off and it gets higher and higher with the same stopping feeling, just higher as it looses vacuum. Then with the engine back in it returns to the half-way down position.

Anyway, the parts are were cheap cheap so fingers crossed!
 

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So you certainly have some vacuum then. The fitting on the vac unit is a 1 way valve, and it failing pritty much reduces the systems pressure. I would pull up some pics of how they work and have a blow down the pipe. I have a feeling the valve is accessable. Its the fitting the pipe goes on to. A serviceable part. I can't remember my source on that though, I could be wrong
 
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