Cobra Brake upgrade kit on an Sn95 doesn't want to brake like it should?

YoshiBluedevil · 02-25-2005

I just put on the cobra upgrade kit from steeda that included 13" brembo rotors, cobra calipers, and steel-braided brake lines. I put them on, and bled the brakes from the furthest to the closest, and its still got a problem. When I push the brake, it feels like there is air in the lines. By that I mean, the brakes dont seem to catch unless I put the pedal almost all the way to the floor. however, if i pump the brakes while i am slowing down (from say ... 50 mph), it seems to catch a little better the more i pump it. BUT, the second i stop pumping, and I just hold it in, the stffer feel goes away.
today, i bled all the brakes about 3 times, and it felt a LITTLE better, but not enough, not like a cobra kit should feel, and even worse then my original kit felt. tonight, i emptied out all of the fluid, and added all new valvoline synthetic brake fluid. i blew all the brakes, and it almost feels worse.
i know ford's upgrade kit comes with a new master cylinder, so i believe that is what I would need, but they dont make them anymore unless its with their kit.
i am sure it is not a vacuum leak because the brakes were fine before, so it shouldnt be an issue now.
steeda said it was cause I have an e-cam, so there isnt enough vacuum, but like i just said, so that cant be it.
the only thing i can think of is a 94-95 COBRA master cylinder.

by the way, i do know what im talkin about when it comes to the feel of the cobra brakes cause my uncle had an 03, and is one of the 2500 with an 04 mysitchrome, so i know how the brakes SHOULD feel ... not that it is helping me much here lol.

anyone have any ideas, or done this to their car and know what the issue is?

89stanger · 02-25-2005

rear disks? stock masters have a one way valve in the front brakes to keep the pads from retracting back into the caliper, i believe it is in the master cylinder, it might be in the caliper it's self, what it sounds like is that u have no valve so that when u push, it pumps up and as soon as u take ur foot off of the pedal, it loses it's pressure and the cylinder retracts into the caliper, if when u pump it up and hold it, it still sinks, i would think that you have a master cylinder problem, is the pedal hard? like take the vac line off of the booster, and drive around the block, does the pedal feel like that? if it does, it's the booster, if it's too soft it's the master, my thoughts on the matter atleast, if it works then the pressure fades while still holding the pedal down, it means there is a pressure leak somewhere, if there is any brake fluid being lost @ the wheels, it could be from that, otherwise it is probibly leaking past the internals of the master cylinder and back into the resivoir, so i would think about replacing it with a cobra master from the same year as the calipers are designed to replicate, so that you have a match set of calipers and master cylinder

YoshiBluedevil · 02-26-2005

ill try some of that stuff this morning. the problem is I have a 94, and the master cylinder is only for the 94 and 95 cobra. the only difference is the cobra has a 15/16" bore, which im sure is making a pressure difference.

by the way, even with the pedal pushed all the was down, i can still turn the front tires with a little bit of muscle. i havent tried to do that on the front, but i think I will try that this morning too.

i will also check for leaks, cause i thought that was maybe the issue too. thanks. ill keep this updated

GhostDog 5.0 · 02-26-2005

Sounds like you still have some air. When you have all the lines open they can get a TON of air and need quite a bit of bleeding.

YoshiBluedevil · 02-26-2005

well its not the booster. i had my friend whos a mechanic do the bleeding as i pumped, and held it in, and such. well, he said there was a little air in the fronts, but we got it all out. it made a little bit of a difference, but the brakes do not grip right still. even when i slam the brakes, it hardly grips. when i pumped it a few times then slammed it, the brake pedal got stiffer, but the brakes almost lagged for a second, then gripped, but just as poorly as usual.
i only have 2 ideas at this point:
1- disconnect the ABS (remove the fuse) and see if that does anything
2- new master cylinder (94-95 cobra only) [very hard to come by]

meatball · 02-26-2005

http://mustang50magazine.com/techart...rakes_install/
http://www.mocatx.com/TechArticle.asp
http://www.rhinobrothersracing.com/brakes.htm
http://sn95brakes.cjb.net/
http://www.allfordmustangs.com/Detailed/2009.shtml
http://www.veryuseful.com/mustang/tech/brakes/
http://www.stainlesssteelbrakes.com/magazine.articles
http://www.musclemustangfastfords.co.../0402mm_roush/
http://mjbobbitt.home.comcast.net/mustang/4lug.html
http://www.mustangmonthly.com/techar...rums_to_discs/
http://mjbobbitt.home.comcast.net/mu...tech_page.html
http://www.mustanggt.org/mods.htm
http://bellsouthpwp.net/j/c/jcchaconjr/4v50faq.html

89stanger · 02-26-2005

abs? pfft! real men slide into the poles! lol jk, it's not ur abs acting up, if it was your pedal would vibrate quite violently, go ga ga ga ga ga ga ga ga ga ga ga ga and shake and scare the crap outa u if uve never felt it b4

YoshiBluedevil · 02-26-2005

the only other thing i can think of is that the 4.6 brakes are different, hydro-something. my only thought is that those brakes push fluid better, or change the pressue, and my setup doesnt. that is why i can only use a 94-95 master cylinder.
if THAT is the case, does anyone know if i can just change the master cylinder to an upgraded (newer) one, and im guessin the booster and stuff too. i just dont know what else to do. i love to drive, but it is dangerous with a crappy working brake system

... i was assuming it would be better stopping cause its cobra stuff

YoshiBluedevil · 02-26-2005

or maybe i need a break-in period??

YoshiBluedevil · 02-28-2005

nobody has any ideas? maybe a cobra master cylinder? maybe some sort of conversion to a newer master cylinder or something? it isnt safe driving with my brakes messed up like this...

privatejoker · 03-01-2005

Sometimes when you bleed an old master, if you push the pedal all the way down and don't put a block of wood or something down, it will ruin it. Just dirt settled being forced through possibly, I don't really know why. The other option is those new calipers require too much volume for your little master to push. Master's are cheap. Do some research on which one you need and if you need any plugs/adjustable proportioning valve to accompany.

YoshiBluedevil · 03-01-2005

well, this is what i saw from sn95brakes.cjb.net:

'94-98 V6/GT - (metric threads) 1 1/16" bore, stock plug in for the low fluid sensor
'94-95 Cobra - (metric threads) 15/16" bore, stock plug in for low fluid sensor. Ports are reversed thread sizes from 87-95 LX/V6/GT

Does that mean if i get a 94-95 cobra master cylinder, that the threads are backwards?

i will try adjusting the brake pedal, like the site says to do with new calipers ... but i do not think that will have a great impact...

shakerhood · 03-02-2005

Quote:

Originally Posted by YoshiBluedevil

well, this is what i saw from sn95brakes.cjb.net:

'94-98 V6/GT - (metric threads) 1 1/16" bore, stock plug in for the low fluid sensor
'94-95 Cobra - (metric threads) 15/16" bore, stock plug in for low fluid sensor. Ports are reversed thread sizes from 87-95 LX/V6/GT

Does that mean if i get a 94-95 cobra master cylinder, that the threads are backwards?

i will try adjusting the brake pedal, like the site says to do with new calipers ... but i do not think that will have a great impact...

It means the ports are on the other side of the master cylinder. It was a failsafe way to make sure when a Cobra went down the assembly line they couldnt put the wrong M/C on it.

stanglx2002 · 03-02-2005

sounds like either air in the lines or the master cylinder i had that problems and mine was the master cylinder

YoshiBluedevil · 03-02-2005

so how can i get a cobra master cylinder? how can i get it to bolt in to my gt?