too much heat=brake pedal stiff?? - Page 2 - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

*NemeGuero* · 01-19-2006, 10:26 PM

Thanks! They're a bit more then I expected though..

Ritz S14 · 01-19-2006, 10:42 PM

OEM ones cost a lot more.

infinitexsound · 01-20-2006, 03:25 AM

forgive me if im wrong... but arent u rockin a ka-t... if ur brake lines are getting heated wouldnt that create ur brakes to lock up... post pics... of ur engine bay.. maybe ur lines are too close to the DP .. neme..

*NemeGuero* · 01-20-2006, 02:32 PM

That's what I originally thought.. I installed this shield though as you can see in this thread..
http://www.zilvia.net/f/showthread.php?t=93903

And I made it all the way from San Jose to Berkeley without a problem.
When I drive "spirited-ly" they'll lock. I'll have to pull over, remove the vacuum line to the booster, and then they'll losen again.

This makes me think it isn't heat related..

I dunno man.

If replacing the MC and booster doesn't fix this.. it's going to the shop.
And if they can't fix it.... I don't even want to think about it.

neilsan · 01-20-2006, 02:52 PM

I wonder if the check valve for the brake master vaccuum pod isnt going bad from boost, pressurizing the tank instead of keeping it hold a vaccuum. i think that would just make it harder to stop, though, instead of push on the cylinder piston itself and stop FOR you. ...i think. If heat expanded the fluid enough to lock your brakes, it should instead back up into the resivoar.

edit: it cant be my first suspicion.

Its got to be the pedal isn't adjusted properly... There's a critical spot where the piston *just* goes past the hole in the bottom of the resivoar. If it's not coming up past that hole, when the fluid heats up, it expands, and without any place to go it is pushing your pads against the rotor. The turbo may not have as much of an effect as you suspect, the calipers themselves can get up to like 600° if youre doing hard braking. It's probably a combination of both, the turbo is heating the lines at the BMC and its pushing on the pads a little, then on the highway the drag is heating up the calipers and the fluid is expanding from that end of the system too.

readjust your pedal. The fix to a problem has to make sense, and that makes lots of it. if adjusting doesnt fix it its most likely the bmc is grody or rusty inside and the piston isnt releasing into its 'home position' properly.

Is there loose 'play' in the brake pedal before you feel resistance when its cold?

EchoOfSilence · 01-20-2006, 04:53 PM

it just sounds like something's clogged. If it's the vaccuum line that hisses, the BMC is either bad or the inlet is clogged. If the BMC hisses, the outlet on the other side of the vaccuum line is clogged.

however, this is just speculation

01-19-2006, 10:26 PM	#31
NemeGuero No more nissan. Join Date: Jan 2003 Location: RAIN, Washington. Age: 40 Posts: 8,132 Trader Rating: (10) Rides Gallery: NemeGuero Feedback Score: 10 reviews	Thanks! They're a bit more then I expected though.. __________________

01-20-2006, 03:25 AM	#33
infinitexsound Post Whore! Join Date: Sep 2003 Location: INtraweb Age: 42 Posts: 3,522 Trader Rating: (0) Feedback Score: 0 reviews	forgive me if im wrong... but arent u rockin a ka-t... if ur brake lines are getting heated wouldnt that create ur brakes to lock up... post pics... of ur engine bay.. maybe ur lines are too close to the DP .. neme.. __________________ S14 TrackSlut coming to a raceway near you... 510 TimeAttack on its way...

01-20-2006, 02:32 PM	#34
NemeGuero No more nissan. Join Date: Jan 2003 Location: RAIN, Washington. Age: 40 Posts: 8,132 Trader Rating: (10) Rides Gallery: NemeGuero Feedback Score: 10 reviews	That's what I originally thought.. I installed this shield though as you can see in this thread.. http://www.zilvia.net/f/showthread.php?t=93903 And I made it all the way from San Jose to Berkeley without a problem. When I drive "spirited-ly" they'll lock. I'll have to pull over, remove the vacuum line to the booster, and then they'll losen again. This makes me think it isn't heat related.. I dunno man. If replacing the MC and booster doesn't fix this.. it's going to the shop. And if they can't fix it.... I don't even want to think about it. __________________

01-20-2006, 02:52 PM	#35
neilsan Zilvia Junkie Join Date: Sep 2004 Location: east coast Age: 44 Posts: 333 Trader Rating: (0) Feedback Score: 0 reviews	I wonder if the check valve for the brake master vaccuum pod isnt going bad from boost, pressurizing the tank instead of keeping it hold a vaccuum. i think that would just make it harder to stop, though, instead of push on the cylinder piston itself and stop FOR you. ...i think. If heat expanded the fluid enough to lock your brakes, it should instead back up into the resivoar. edit: it cant be my first suspicion. Its got to be the pedal isn't adjusted properly... There's a critical spot where the piston just goes past the hole in the bottom of the resivoar. If it's not coming up past that hole, when the fluid heats up, it expands, and without any place to go it is pushing your pads against the rotor. The turbo may not have as much of an effect as you suspect, the calipers themselves can get up to like 600° if youre doing hard braking. It's probably a combination of both, the turbo is heating the lines at the BMC and its pushing on the pads a little, then on the highway the drag is heating up the calipers and the fluid is expanding from that end of the system too. readjust your pedal. The fix to a problem has to make sense, and that makes lots of it. if adjusting doesnt fix it its most likely the bmc is grody or rusty inside and the piston isnt releasing into its 'home position' properly. Is there loose 'play' in the brake pedal before you feel resistance when its cold? Last edited by neilsan; 01-20-2006 at 03:09 PM..

01-20-2006, 04:53 PM	#36
EchoOfSilence Nissanaholic! Join Date: Aug 2003 Location: Los Angeles/Berkeley, CA Posts: 2,238 Trader Rating: (1) Feedback Score: 1 reviews	it just sounds like something's clogged. If it's the vaccuum line that hisses, the BMC is either bad or the inlet is clogged. If the BMC hisses, the outlet on the other side of the vaccuum line is clogged. however, this is just speculation __________________ Petition Nissan to Make the IDx on http://IDxClub.co !

01-19-2006, 10:42 PM	#32
Ritz S14 Post Whore! Join Date: Jul 2004 Location: C A L I F O R N I A Age: 43 Posts: 3,586 Trader Rating: (0) Feedback Score: 0 reviews	OEM ones cost a lot more.