Well, aside from testing the brake booster to make sure that's not the problem, the only other things I can think of to look at would be the brake lines and calipers themselves (maybe you have a blockage in one of them) and the ABS module.

 

Did you ever find a resolution for this problem? I have an 05 G coupe and have the exact same problem that you do. I've bled the brakes and changed the pads, but before I go and mess with the booster, I'm curious if your problem was the booster or maybe it was some sensor. Thanks for your help!

 

No, I never did find a resolution. I am not sure where you live, but I live in Vancouver, Canada. The weather just started getting cold again about a week or 2 ago, and that's when the problem started again. My car was fine for the last few months since the weather was better. But this issue just started again a week or 2 ago, and has happened every day since then.

If you figure anything out, do let me know.

 

I'm in Southern California and that is about the time my brakes started to act up, just as the weather got colder at night. If I figure it out, I'll be sure to let you know. Do you have the 6MT? When it's hot out and I'm in stop and go traffic, my clutch pedal sticks too!

 

No, mine is an automatic so I don't have that particular issue.

 

Hmm, I just replaced all my vacuum lines and the one way valve is located in that hose by the passenger side that connects to the top plenum. You should only be able to blow threw it on one-side; I installed it backwards at first (you need to re-use it) with new hoses and the pedal would go to the floor if it didn't work.

You can disconnect the master cylinder off the brake booster without messing up the brake fluid. I did it myself since I was having some brake problems a few days ago. There is a rubber gasket that sits between the two. Mine didn't look like it was sealing properly.

Maybe you have some air/moisture in the brake lines? If you bought the car used or depending how old the fluid is maybe it needs to be changed? I would try replacing the brake fluid or at least bleeding them to see if any air comes out. I just did it with some Valvoline 3/4 and Motive power bleeder by myself for the first time and wasn't to difficult.

You can test the booster if it's hard when you press down when the car is off. Hold the pedal and turn the engine it should slightly move down. Then when you turn it off the pedal should move up slowly.

You can find a booster on eBay for like 50 bucks and master cylinders are like <150 if it's those. But, if it's impacted more during the winter I'm thinking maybe there is air or moisture in there and the weather is causing problems for you. Sounds far fetched, but you never know.

 

I had already checked my one way valve and it was working as it should (only able to blow through one side).

I don’t really think it is the booster or the master cylinder, but I will check to see if it is not sealed properly.

I also doubt there is air/moisture in the brake lines, but again, worth checking.

The reason I do not think it is any of the above two reasons is because it really feels like a vacuum type issue. It will only happen the first time I start the car on a cold day, and it is after the second or third pump of the brake each time. After this has happened, it will not happen again for a second time on the same day, even if the car has sat for lengthy periods of time. It seems like a very specific problem, whereas the other issues mentioned could be ongoing problems with the braking system.

Mine has the same issue each cold day,
-first start
-second or third time I hit the brake, brake pedal gets stiff (as if you are pumping the brake without having the car started)
-then while holding the third pump after a second or two pedal goes down all the way as it should (like when testing the booster, by pumping the brake a few times, then turning the car on to feel if the pedal goes down), and works fine for the remainder of the day.

I could be completely wrong, but it feels like the one way valve gets stuck overnight, and once its forced open, it works fine for the rest of the day. I wanted to replace the hoses, but I was told they do not sell new hoses with the check valve already in place.

 

Does the car RPM change at all when you press the brakes? I've heard that if there is a problem with the vacuum that usually occurs as well.

See if your Nissan dealership can get you part number: [47474+A] - Hose Booster- 47474-Z33001 that's the engine side brake booster for 350Z/G35. It's about 18 bucks at the courtesyparts.com.

 

Did you try removing the vacuum line from the booster while the engine is running? The engine should stall... if it doesn't your vacuum line might be clogged. Remove vacuum line and test again. If still clogged, check the port going into the plenum.

Had this problem with a 4runner a while back, vacuum sucked up some twigs and blocked the manifold intake port, caused the same symptoms as you are describing.

 

Same issue in Canada in the mornings and after a 12 hour shift. I have been dealing with this issue for over a year so I just came to the conclusion of pumping the breaks till it works before I take off and hit someone. I recently did my rotors pads and flushed my break lines but that hasn't changed anything. I am guessing I have a bad caliper because I did replace a bad one with a used one when I first bought the car and I have had my abs go crazy a couple of times. It's kind of an annoying problem so if anyone figures it include me.

Thanks

 

I think I have the same issue. In Atlanta, and got cold here last night. In the morning, I felt that the brake pedal was stiff. Stayed about the same throughout the day until I pressed really hard on the pedal then it got a little better. I haven't had the chance to look into it yet. Any updates would help. Thanks

 

try this for troubleshooting.

Car off, pump the brake pedal a few times to bleed off any vacuum in the booster. The pedal should firm up. Apply a little pressure to the brakes, enough to hold the car at a stop light. Start the car. Upon startup, does the pedal sink a little and get softer in feel indicating the booster is now seeing vacuum internally? If the pedal does not change at all, then you do not have vacuum inside the booster and need to investigate why.

Do you have aftermarket camshafts? Sometimes these reduce the amount of vacuum an engine creates. You may need to run a vacuum canister in this case to store vacuum for the brakes.

There is a 1way check valve on the booster. The vacuum line connects to this and it's mounted external to the booster. It allows air to be drawn out of the booster and then to store. If you have vacuum in the AM, this is prob functioning ok, but since you said this happens when cold, it's possible moisture is freezing the valve closed preventing it from opening and depleting the vacuum inside the booster when you hit the brakes.

 

Hello, I also live in Canada and have the same problem. My dealer replaced the hose but that did not solve the problem. Now he thinks the booster needs to be replaced. Can you tell me how you resolved the problem.

 

The clutch pedal issue on the 6MT started happening to me last week.

Kind of annoying since I have the brake issue also. From what I've read, try flushing/bleeding the clutch fluid first and see if that solves the problem. If not, then move on to the Clutch Slave Cylinder. I'm gonna have this done this week, so I'm hoping that fixes the issue.


Thanks for the suggestion, I will give this a try.

I have this same issue, so I guess this is a common problem with the 6MT esp in the cold? I have performed the brake booster tests and most of the time it passes. The issue happens only after a couple of miles.

The weird thing is after you drive a longer distance, it doesn't seem to happen anymore. I drove my car 2 weekends ago all over town and didn't have the issue. It seems to happen only like 5mins after leaving my house--it always happens when I'm 2-3miles away. I actually broke down twice in the same spot.. which was really annoying and frustrating.

I bought my car exactly a month ago when it was not cold and it did not have this issue on the test drive (weather was warm at the time). When the temps dropped down a bit a couple of weeks ago, it started having the brake issue.

So far I have had the brake fluid flushed/bled and even replaced the Brake Booster by a local shop and it still happens. So its definitely not the Booster, Master Cylinder, or Pads/Rotors.

So if anyone has this issue, do not spend money on a brand new Booster. It cost me over $800 at Midas, which I thought solved the issue until it happend again a few days ago.

 

Let me know when you solve the problem. I'm thinking of having the booster replaced, but there seems to be by some on the tread that's not the problem.