Notices
Brakes & Suspension 350Z stoppers, coils, shocks/dampers

need help troubleshooting spongy brakes

Old 11-18-2009, 05:23 AM
  #1  
a7med
Registered User
Thread Starter
 
a7med's Avatar
 
Join Date: Nov 2009
Location: Dubai
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Unhappy need help troubleshooting spongy brakes

Cliffs:
Brakes became spongy
Checked for leaks, no leaks
Rotors and pads were replaced with genuine brand new (non-brembo)
Repaired brake master cylinder with repair kit and then ...
Tried to bleed brakes but no pressure

Where have I gone wrong? what can I do? Driving with hand brake and 6MT at the moment, so your help will be a life saver!

Thanks.
Old 11-18-2009, 06:19 AM
  #2  
endless_summers
Registered User
iTrader: (1)
 
endless_summers's Avatar
 
Join Date: Feb 2009
Location: Chambersburg, Pa
Posts: 77
Likes: 0
Received 2 Likes on 2 Posts
Default

what does this master cylinder repair kit consist of? if you had the master cylinder off, did you bench bleed it?
Old 11-18-2009, 06:28 AM
  #3  
a7med
Registered User
Thread Starter
 
a7med's Avatar
 
Join Date: Nov 2009
Location: Dubai
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by endless_summers
what does this master cylinder repair kit consist of? if you had the master cylinder off, did you bench bleed it?
the kit consists of the tandem pistons (secondary and primary), o-ring, x2 seals, silicon grease, pin which hold the reservoir to master cylinder, and that C-shaped clip which holds the pistons inside the cylinder.

Bench bleed? ... oh $hit!

Last edited by a7med; 11-18-2009 at 06:35 AM.
Old 11-18-2009, 09:24 AM
  #4  
DavesZ#3
350Z-holic
iTrader: (26)
 
DavesZ#3's Avatar
 
Join Date: Jul 2003
Location: Louisiana
Posts: 15,887
Likes: 0
Received 22 Likes on 17 Posts
Default

They just "became spongy" for no apparent reason?

You've got air in the lines, you need a pressure bleeder to get it out. Regular pump-the-pedal bleeding won't do it.
Old 11-18-2009, 10:59 AM
  #5  
JCat
---------------
iTrader: (4)
 
JCat's Avatar
 
Join Date: Mar 2004
Location: JC in Atlanta Georgia
Posts: 3,985
Received 73 Likes on 48 Posts
Default

Will pressure bleeding overcome the fact that he did not bench-bleed it? My guess is not.
Old 11-18-2009, 11:17 AM
  #6  
plumpzz
New Member
iTrader: (10)
 
plumpzz's Avatar
 
Join Date: May 2005
Location: Jersey, New
Posts: 7,146
Likes: 0
Received 0 Likes on 0 Posts
Default

My gf's car was spongy. Her problem was pads/rotors that needed to be rescrubbed. I removed the pads and used some light sandpaper to clean up the pad and the rotor and broke in the brakes again using stoptech's procedure.
Old 11-19-2009, 07:41 AM
  #7  
a7med
Registered User
Thread Starter
 
a7med's Avatar
 
Join Date: Nov 2009
Location: Dubai
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by DavesZ#3
They just "became spongy" for no apparent reason?

You've got air in the lines, you need a pressure bleeder to get it out. Regular pump-the-pedal bleeding won't do it.
Not suddenly, but from wear I believe, tried bleeding several times. The problem now is the repair kit, wish it was spongy but there's no pressure whatsoever.

Originally Posted by plumpzz
My gf's car was spongy. Her problem was pads/rotors that needed to be rescrubbed. I removed the pads and used some light sandpaper to clean up the pad and the rotor and broke in the brakes again using stoptech's procedure.
did it work? usually you need to resurface the disc to get rid of the grooves and make it smooth.

On the other hand, I just came from hell, I've took the master cylinder out again and bench bled it, didn't work, went to a workshop and we took it out again, this time I opened it, I noticed the O ring which is on the primary tandem was out of place, in fact it was further inside the cylinder hanging loose around the piston, which made the oil leak outside into the break booster (I flushed the engine and changed oil), anyway *face-palm* I was relieved, I thought my nightmare was over, fixed the ring in place, tried to bench bleed it, there was little or no pressure improvement as there was before, so we basically achieved NOTHING, there's very little pressure.
The guy at the workshop says I must get a new complete master cylinder and that a repair kit is useless and that the cylinders bore itself is the problem, fine, but What I don't understand is how come the old master cylinder which I took out at least had pressure and was working to some extent? Around 10 liters of brake oil wasted so far. Driving with no brakes for the last two days relying on the handbrake and manual transmission to slow down.
I told him I am ready to buy a new master cylinder but it was out of stock, until Saturday, anyways until then I am ready to try any other idea that might make this work, as I've come a long way already.

Last edited by a7med; 11-19-2009 at 07:45 AM.
Old 11-19-2009, 10:24 AM
  #8  
ITOzann
Registered User
iTrader: (30)
 
ITOzann's Avatar
 
Join Date: Sep 2008
Location: San Francisco
Posts: 2,387
Likes: 0
Received 1 Like on 1 Post
Default

That sucks! I have a master cylinder coming from an 08 if you are interested.
Old 11-19-2009, 10:29 AM
  #9  
JCat
---------------
iTrader: (4)
 
JCat's Avatar
 
Join Date: Mar 2004
Location: JC in Atlanta Georgia
Posts: 3,985
Received 73 Likes on 48 Posts
Default

When you are dealing with hydraulics, any nick, burr, or damaged rubber will cause the system to fail.

Why did you opt to rebuild the master cylinder in the first place?
Old 11-19-2009, 02:07 PM
  #10  
a7med
Registered User
Thread Starter
 
a7med's Avatar
 
Join Date: Nov 2009
Location: Dubai
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by ITOzann
That sucks! I have a master cylinder coming from an 08 if you are interested.
I have a 04, but thanks.

Originally Posted by JCat
When you are dealing with hydraulics, any nick, burr, or damaged rubber will cause the system to fail.

Why did you opt to rebuild the master cylinder in the first place?
Brakes were spongy and soft, and they don't lock when I fully depress the pedal, car drags to a stop. What else could it be? are these symptoms of soft brake lines? I'll know on Saturday when I get a new BMC
Old 11-21-2009, 12:44 AM
  #11  
a7med
Registered User
Thread Starter
 
a7med's Avatar
 
Join Date: Nov 2009
Location: Dubai
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Default

... Ok $hit's just got serious, no BMC in stock, next time it'll be in stock is in a month or so ... need to make what I have work ... I am gonna open it again tonight, from what it looks like, there's no pressure in the cylinder, I know for sure there's no leak towards the brake booster anymore (fixed), where can the pressure be going? can it be lost inside the cylinder itself? what should i look for?
Old 11-21-2009, 07:15 AM
  #12  
terrasmak
Super Moderator
MY350Z.COM
iTrader: (8)
 
terrasmak's Avatar
 
Join Date: Jan 2007
Location: Sin City
Posts: 28,635
Received 2,283 Likes on 1,645 Posts
Default

Originally Posted by plumpzz
My gf's car was spongy. Her problem was pads/rotors that needed to be rescrubbed. I removed the pads and used some light sandpaper to clean up the pad and the rotor and broke in the brakes again using stoptech's procedure.
No Comment
Old 11-21-2009, 11:33 AM
  #13  
a7med
Registered User
Thread Starter
 
a7med's Avatar
 
Join Date: Nov 2009
Location: Dubai
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Default

ok new $hit has just surfaced .... i opened the cylinder to have another look at the repair kit, and it seems like the rubber rings around the tandems are smaller than the ******* bore, 3 rings in total, 2 around the secondary tandem and 1 around the primary, technically when i put them inside the bore and shake the cylinder they wobble freely as in they don't snug fit in it, similarly to how when you put your dick inside a ***** that's been F***ed too much too often and you don't feel anything ... in other words I GOT THE WRONG MOTHERFCUKING KIT!
Old 11-21-2009, 12:50 PM
  #14  
JCat
---------------
iTrader: (4)
 
JCat's Avatar
 
Join Date: Mar 2004
Location: JC in Atlanta Georgia
Posts: 3,985
Received 73 Likes on 48 Posts
Default

RE: dick inside ***** and don't feel anything.............TMI......you may have a big problem there. Sorry.
Old 11-22-2009, 02:30 AM
  #15  
a7med
Registered User
Thread Starter
 
a7med's Avatar
 
Join Date: Nov 2009
Location: Dubai
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by JCat
RE: dick inside ***** and don't feel anything.............TMI......you may have a big problem there. Sorry.
yes i do a have a problem here after i coughed up $64 for the wrong repair kit, the wasted oil, time, useless labour charges, and having to wake up too early and sleep too late, and after all this and the driving with no brakes, i just coughed up another $262 for a new bmc.

Last edited by a7med; 11-22-2009 at 02:56 AM.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
07ZEKE
Brakes & Suspension
2
08-23-2021 09:15 PM
hajwoj
Autocross/Road
27
11-01-2015 05:25 PM
samansharif
Brakes & Suspension
1
09-25-2015 12:31 PM


Thread Tools
Search this Thread
Quick Reply: need help troubleshooting spongy brakes



All times are GMT -8. The time now is 01:43 AM.