# The Great Brake Conundrum....



## MDVDuber (Nov 20, 2002)

Ok, Lot's of info, a few theories and much frustration, please bear with me. I'll lay it out in a 1, 2, 3, a, b, c fashion so feel free to respond to just one of my issues. Feel free to ask questions if I've missed something.

Car = 1992 Jetta GL with 10.1 inch front brake upgrade

1) Upgraded to 10.1's a number of years back. Never happy with pedal feel

2) Rebuilt rear drums a number of years ago - new cables too
2a) Ordered e-brake cables from Adirondack - they are too long - even though they are 1535mm in length which is spec for my car.
2b) Shimmed e-brake cables to make them work - sort of.
2c) Not really happy with e-brakes - so clearly not good drum self adjustment.

3) Recently did a complete replacement of all brake hard lines and new 22mm Master Cylinder and new rear proportioning valve - I'll say again - NEW Master Cylinder that passes all the "pump it up to pressure and see if pedal falls" tests. Still crappy pedal feel
3a) yes I bench bled the new MC
3b) 2 litres of brake fluid passed through system via a Motive brake bleeder - fluid is nice and clean.

4) Tonight when pressing brake pedal I get this weird catch with a clunk/click sound. When I crawl under the dash it looks like where the vacuum booster comes through the firewall is moving when I push the pedal - but I think I get plenty of vacuum boost. This issue actually concerns me most? Maybe?

Still Pedal feels - bleh - lot's of travel before it engages - but when it does I can lock 'em up no sweat....


So my theories

1) Because e-brake cable isn't kosher - I can't get the rear brakes to self adjust - this causes long pedal throw.

2) My car is a late model 1992 - did VW maybe substitute parts from the 1993 model - that had a 1495mm long e-brake cable?? Certainly other parts are NOT 1992 GL spec and the PO was not a modder. Yeah I'm the 3rd owner of this car - she's been mine since 1998. See why I can't bring myself to sell her in favour of an e30 BMW..

3) ARRGGHH!


Ok so that's my story and the poster who can actually figures this out get's a six pack of whatever I just finished brewing :beer: - FYI - a Highly hopped Barley Wine is next on "tap"


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## GTijoejoe (Oct 6, 2001)

Crazy frustration... I'll point you in the most important direction first. If your fire wall is moving as you press the pedal you need to confront that problem asap. Everything about your brake sysem is focused around your application method, this case the pedal. The firewall is absorbing some % of your input force which is not being transferred to your hydrualic system and eventually your caliper force.

It is possible that your firewall has developed a crack... other ways to stiffen it up is to apply a spacer to double or tripple the thickness of the firewall in as big as a section area as you possibly can. 

That should get you started, I wouldn't even look into anything else until you got that situated and see how your pedal feels after.:beer:


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## MDVDuber (Nov 20, 2002)

GTijoejoe - Thanks for the reply. I got under there last night and had my wife press the pedal for me (and she didn't kick me in the head - I got me a winner!). Anyhow, it doesn't appear that the actual fire wall is flexing - but rather the part of the vacuum booster that comes through the fire wall is moving. The 4 nuts holding it don't move - the actual "tube" that comes through the firewall does. If that doesn't make sense - I can shoot a picture of it.


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## GTijoejoe (Oct 6, 2001)

I actually don't know exactly what your speaking of, pictures would help.
I will add that there needs to be some type of input rod through the booster to press the master cyclinder...perhaps that is what you see


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## MDVDuber (Nov 20, 2002)

Ok, the "sleeve" where the rod passes through the fire wall deflects when I press the brake pedal. The plate that is bolted to the fire wall is steady as a rock....

Does that make more sense?


Edit to flip the Picture upright....


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## GTijoejoe (Oct 6, 2001)

That motion should be completely normal


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## MDVDuber (Nov 20, 2002)

Update in new properly titled thread: http://forums.vwvortex.com/showthread.php?5032993-Vacuum-Booster-Noise

Thanks in advance for any assistance.


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