350zguy12345

Hey guys,
I have a 2004 350z that only has 45k miles on it. Recently the brakes have started giving me trouble and no one can seem to fix it. The brakes are lightly applied almost all the time. They are sticking about 1/4 of the way down and I cannot get them to come back up until the car cools off. You are probably going to say, why the hell haven't you had someone look at them. Well I have 5 times now, the master cylinder was rebuilt, the calipers were rebuilt and lubercated, the lines were flushed 3 times, the brake booster was rebilt, and the lines were checked for kinks, basically everything I've thought to have done has been done. And guess what, the brakes still stick....... What happens is I drive the car for about 10 min, once it warms up the brake pedal gets kinda hard and has about half the travel it shpuld. Then the car feels slugish as it rolls in neutral. Its a manual car so I know it's not the transmission.... After a while the car is almost undriveable because the brakes drag so heavily. Also the pedal is not stuck down, it is fully back in the normal position so I do not think it is the pedal it self. As you can see this thing is cost me a fortune, if any of you guys know what is going on please let me know. Thanks

samsniss350z

It sounds like the pistons are sticking in the bores of the calipers.

kamilitaryman

iTrader: (1)

Sounds to me like either the caliper slider pins or the actual pistons are seizing up. Who rebuilt the calipers the 1st time around? How about the e-brake? Is that acting up?

350zguy12345

Thanks for the responces, they thought that the calipers were the issue the first time. I had a family friend (a mechanic) rebuilt the front 2 calipers. This did not seem to help at all. As for the e brake I'm pretty sure its not the issue, it goes all they way back in place and it words just fine when I'm parking. I'm pretty sure it's the main brakes considering the pedal gets messed up too. I don't think the rear brakes have been replaced. What do you think I should do?

350zguy12345

And something I forgot to mention. The e brake works fine, I will sometimes use it after I engine brake to like 5mph and it seems normal to me.

icer5160

iTrader: (4)

Need more details, what trim package Z do you have? Is this the touring/track version? Do you have the Brembo brakes or the base model non-Brembo?

The non Brembo brake calipers and pads should have spring clips that slot into the caliper mount that push the pads out (away from rotors) preventing dragging issues. These springs need to slot into loop/hooks on the pads for them to work properly. If the brake pad install was not done correctly, this can easily cause a dragging issue.

Other Dragging issues to consider with the Non-Brembos are the floating caliper pins/bolts. There is a specific orientation (top vs. bottom) for these as each pin/bolt is unique.

The Brembo brake calipers have a cross spring plate used for the same purpose, it's pretty obvious on the Brembos if this was not installed correctly.

Elsewise, It could be something like the brake booster if you already addressed the master cylinder.

Pictures would be a great help.
Good Luck!
-Icer

350zguy12345

Thanks for the suggestion, I'm not sure if they are installed correctly I will definitely check it out. I don't think so though, they are the non brembo brakes and they were just checked out and redone.

350zguy12345

Also it is a touring package, not sure if that makes a difference. If I took a picture of the caliper would you be able to tell if the pad was installed correctly? Because it seems fine to me but I have no idea. Also does anyone know what the piece is called that is under the brake pedal. It has a black rubber boot around it and is bolted to the floor under the brake. The brakes pushs it in and it does something, but I'm not sure if that could be the problem?
Also the booster was rebuilt a few weeks ago, not the problem apprently

icer5160

iTrader: (4)

This pic shows the non-brembo pad installation. Please include a picture of this switch or rubber boot under the brake pedal.
-Icer

icer5160

iTrader: (4)

The brake sensor should be at the top of the pedal arm, not under the pedal. So I'm wondering what that thing is as well other than a rubber stop or pad, there shouldn't be anything else under the brake pedal. See diagram below...

dboyzalter

iTrader: (3)

Sooo do you know what is sticking? When it warms up you should be Able to pin point what brake is binding up. You should be able to smell, or at least feel the heat on the rotor thats binding... Once you figure out what side is binding then investigate.

I would put my money on a stuck caliper, or something like a old spring broken off in your emergency brake...

Have you investigated the emergency brakes?

I would have gotten rebuilt calipers from a chain store, at least they have a warrantee, and a return policy.

350zguy12345

Well I'm almost 100 percent sure it's not a caliper sticking. Here's why, the wheels are the same temparture after I stopp, and the car does not pull to one side. So unless all of the calipers are messed up, I don't really think its a sticking issue. Oh I guess the thing in the black boot it called the input rod to the brakes. Do you think it could be sticking and causing my issues? Thanks again for all your help guys I really appreciate it!

And I don't think the e brake is the problem? It seems to be fine, I mean I've had this car for a year's and it feels the same it always has. Do you think it could be the e brake even if I don't feel anything wrong with it??

dboyzalter

iTrader: (3)

My guess is the e brake one side might work fine and the other side could be your trouble, dont know how it would get messed but things are right in their. Still dont get why it only happens after the cars been driving though...

Your whole situation is odd...

Here is what the ebrake looks like, maybe a spring broke

350zguy12345

Yeah it's definitely worth checking into the e brake situatuon, however I'm a little skeptical that's the issus, because the brake pedal physically changes in how it feels. Do you think an e brake problem could change how the main brake system performs?

And yeah I know man tell me about it, this is the strangest problem I've ever had or seen with a car, I've had 4 different repairs done and 2 different mechanics tell me they cannot fine anything wrong with the car. But I swear I'm not crazy this is seriously happening!! I know it for a fact because today when it happened i was on a hill, and the car was in neutral with the clutch in and the e brake off, and guess what.....
The car did not roll back. FML

terrasmak

iTrader: (8)

In my years I have had a caliper stick only when hot, get a $10 temp gun from harbor freight and check rotor when this happens. It will pinpoint a caliper , or tell you if all are having problems.

From there, I have also had a propertioning valve go bad it it effected my 2 front calipers , we don't have one, but we do have an ABS block. Something internal on the ABS block could be bad.

JLocke

I had the exact same problem and it was my brake pedal itself. The pedal was depressed about 1/2 an inch and it caused my rear brakes to drag after a few minutes of driving and nearly lockup after a couple of miles. It started with me replacing my "stop light switch" [brake lights]. While replacing it I incorrectly installed the switch by depressing the brake pedal and THEN attached the switch. Doing it that way caused the brake pedal to remain depressed an additional 1/2 inch. That's it. Nothing else. After I removed and reinstalled the switch properly, without depressing the brake the pedal returned to its normal position [M/T Model (6.06- 6.46 in) and A/T Model (6.38 - 6.77 in)] then the car drove completely normally.

JLocke

[SOLVED]
I had the exact same problem and it was my brake pedal itself. The pedal was depressed about 1/2 an inch and it caused my rear brakes to drag after a few minutes of driving and nearly lockup after a couple of miles. It started with me replacing my "stop light switch" [brake lights]. While replacing it I incorrectly installed the switch by depressing the brake pedal and THEN attached the switch. Doing it that way caused the brake pedal to remain depressed an additional 1/2 inch. That's it. Nothing else. After I removed and reinstalled the switch properly, without depressing the brake the pedal returned to its normal position [M/T Model (6.06- 6.46 in) and A/T Model (6.38 - 6.77 in) from the metal floor] then the car drove completely normally.