Sorry I missed you guys at the event last weekend. I was planning to go and then encountered a front brake problem with my 88 300zx.

Here's the details:

Approx 1 month ago, I changed the front rotors and pads with a buddy. I used NAPA parts. The pedal dropped down 3/4 to the floor, so I bled the brakes. Still the same problem.

Brought to my mechanic to flush the entire system and put in new fluid. No change. Had them put in a new master cylinder with very little improvement. You know have to pump the pedal once to get the brakes to engage and grab. Their only suggestion now is to throw in new parts (calipher etc.). Note all the lines are okay and no leaks

Am I missing something with the pads ? They are ceramic from NAPA. Is it possible they do not work the same as OEM from Nissan ?

I'm grabbing at straws now, I went from a DIY project to something now costing me $700 or more. The mechanic is dumbfounded and has little Nissan background (SAAB/VOLVO). I'm starting to freak out as I'm dumping money into a repair that I did only cause the rotors were rusted. The brakes were fine otherwise until I started on this adventure.

Any help from the forum would be appreciated. If you have experience or know a mechanic that has worked this angle, let me know.

Not getting the warm and fuzzy feeling with driving the car the way it is.

Many thanks, sorry for the venting.

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2005 350Z Grand Touring Convertible

Hi Kevin~
Yeah, we missed you and about 4 other members. Everyone else seemed to have made it. NEXT TIME, GUY! (However, you did the responsible thing by staying home if you don't trust your brakes. Congratulations on the self-control).

Do you still have the old rotors and pads, or did you toss them?

Frank T
MbrshpDir

Did you perhaps switch the calipers from right to left? I ask because a friend of mine did this on his car and had the same issue.

The Bleed Nipple on the calipers should be towards the top of the caliper, air bubbles rise, to get a proper bleed.

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I never changed the calipers as there was no need. We obviously pushed the piston in with the c clamp for clearance. I don't have the original pads and rotors. Wondering if the pads may be fitting wrong and if I should try Nissan pads.

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2005 350Z Grand Touring Convertible

I wasn't suggesting you replaced the calipers. I thought you may have removed them to replace the rotors, and switched them side to side by mistake.

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It's curious tho, that he should lose pedal with a brake replacement. Even if the new pads were thinner than spec (like maybe they gave him the wrong ones), the old pads were probably worn thinner than the replacement pads would be.
If he installed new rotors, they should be max spec for thickness, so they wouldn't cause the pedal to fall like that. I'm ASSUMING he bled the entire system correctly (do you get a steady, hard pedal eventually?).
The next thing I would "guess" would be that the partZ dude misread the spec sheet and gave him the wrong partZ. The only way I would check for that would be to read the numbers off the boxes and confirm with ANOTHER partZ place that those pads/rotors were meant for my year/model car.
Frank

Hi Frank and Barry

On the calipers, I'm pretty certain they were put back on correctly. I did bleed the system the two man method in opening the value with the other person pressing on the brake pedal. I also had the entire system flushed by the mechanic (2x; once initial and once for the add of the master cylinder). I can pursue the pad question with Napa. Do you think I'm better off getting the pads from Nissan (OEM). I priced them at $80 with discount from Darien Nissan.

Just getting flustered with something straight forward running up to $700.

Thanks for any input..

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2005 350Z Grand Touring Convertible

Another thought..I did some googling and came upon the notion of bad axle bearings. I didn't remove and repack bearings because they didn't look worn and area was clean. Wondering if they could be cracked or need checking. It sounds like the thing both I and the mechanic uncovered with the pumps to the pedal to get normal operation. Right now I'm reaching.


Failing Axle Bearings - The vehicle axle bearing holds the wheel true to the axle shaft while allowing the wheel to rotate. If the bearing fails it will allow the rotor to move back and forth, forcing the brake pads inward into the caliper. Then as you apply the brake pedal it will go to the floor as the caliper fills with fluid. In this case it may take one or two pumps to the brake pedal to regain normal operation. Inspect and replace failed axle bearings as needed, finish by bleeding and adjusting the system.

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2005 350Z Grand Touring Convertible

Lift the front wheel on a jack. Grasp the front & rear of the tire and try to shake it fast in a "wobble" fashion (left hand forward, right hand back, then reverse). Then grasp it at the top & bottom and repeat. Tell us if you get any motion or weird noises in either direction. Then lift the other front wheel and try it, too.

(PLEASE. I meant to say please).
Frank

Oh, wait ~ I just re-read your earlier entry. You say you replaced a master cylinder too? When you bled the brake system, did you bleed it using the nipples at the wheels, AND at the side of the master cylinder under the hood?

I bleed the system at the nipples on the wheels. When that didn't work I took it to the garage as they had a vacuum system to flush the system. Not sure if they bleed at the master cylinder. I'll try the wheel thing when I get the car back. Was pondering if there was anything else I should have them do.

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2005 350Z Grand Touring Convertible

Barry, you're better equipped to answer this than I am ~ my sole focus in life is the 240Z and that brake system is pretty basic. A Z31 or Z32 might have "magic" valves in the system which require special bleeding? I can't picture any new partZ allowing so much piston expansion at the wheel that the pedal would fall that much. Out of my league. (HINT: If there is a cross-over system *front-rear*, you should have to bleed the rear wheels too, if the mechanic didn't already do that)

Even if the rotors and pads are thin, once pumped up, they should stay pumped up. The master could have been the culprit the whole time, and by depressing the piston back into the caliper, dirt and sludge could have gone pass the seals, finishing it off. Now if the new one wasn't bench bled, you'll be bleeding for a long time. Also pumping a master with dry o-rings will waste it also. You should let the fluid soak awile in the new one, then bench bleed. When installed in the car, slowly bleed the master 1st, don't pump the pedal a whole lot or fast, go easy. You could waste even a new master if not done correctly. So now that it's in the car, bleed the master, do more than you think should be done, just to make shure. Then start with the furthest tire and bleed one at a time. I usally gravity bleed, just open the bleeder and let it flow. DON'T let the resevoir run dry, or start all over. If you have some one pump the breaks, go slow and easy on pushing the pedal. I do this all by my self, so should not be to hard, unless there is some other issue, like ABS motors have to be actuated, or there is a leak and you can't find it. Like inside the caliper boot, no fluid on the outside, but just a little inside the boot, rare, but can happen.

Hi Paul

I'm going to take it to Nissan on Thurs for a diagnostic. I'll need to drive it roughly 10 miles from the mechanic to the dealer. Is there something I should or should not do while driving it ? I'm also going to take your suggestion on bleeding the master to them.

At this point I'm not sure what the original mechanic did once he installed the new master cylinder. They were taking the attitude of let's throw more parts at it and the problems appear out of their league. The mechanic I talked to at Nissan felt it sounded like a bleeding issue. In hindsight, I probably should have gone there first after the two man bleeding didn't work.

I appreciate all the help guys. Just hope we can get to root cause.

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2005 350Z Grand Touring Convertible

I just wish we could get you your $700 back.

Well, good luck there, and I hate to say it, but you can buy a z31 for $700 nowadays. So as long as your e-brake works, go for it, but thats just me, I can drive just about anything in bad shape. No Fear, but others would call it stupidity, but that's the redneck side of me, can't help it. Now if you want to try once and save some money, crack all 4 bleeders, keep the master filled, get a lawn chair, some food and beer if desired, and just let it bleed like a pig. O' yea, have a T.V. out there to watch the exciting games that are on. In other words, patients could prevail success. (and save money too) If ABS is involved, and if still not working, activate the ABS. Drive it to a spot where the tires would slide, gravel, grass, ect., and slam on the brakes, the motors will activate and bleed the rest of the air out of the system. (just make shure nothing is right in front of you.)