imports_only1

Ok guys, this will be a long post because of what's going on so bare with me. I need whatever advice you guys can give me because I'm getting the run-around with this mechanic on my '98 Maxima SE w/ 165K miles.....

Over a month ago, my brake pedal was very soft. I have to push the brake pedal to the floor to try to stop the car. My first impression was that there was probably air in the brake lines. So I bled the brake fluid according to the FSM. Result? Same thing...brake pedal needed to be push to the floor to stop the car. I bled it again and yet the same result. Then I took my car to my usual mechanic to have it check it out. He said it was the master cylinder and charged me $200 to replace it (reman. part) and bled the fluid. The next day, my brother went to pick up the car and drove it home. I asked him how's the brake. He said it isn't any better. So I took it for a test drive and sure enough, the brake pedal was as soft as a pillow. I took the car back to the mechanic the following day. Now, he said it was the front calipers sticking and rotors being warped. Being pretty handy with tools and car stuff, I changed the front rotors, pads, and calipers....and test drove it. Same result...WTF!!!! I was getting quite upset here with this mechanic. I took it back to him and he had it over night. The next morning I called him to see what's going on. Now he said the rear rotors and calipers are sticking and not grabbing the rotors probably. Of course, I knew how to change rotors and calipers myself so I bought some aftermarket rotors and calipers with OEM pads and changed them. Test drove it....F_CKING SAME THING! NOW...I was really pissed! Mind you, I bled the brake fluid each time I changed the rotors, calipers, pads... The following day I took it back and gave him a hard time. Again, he had the car for the morning and afternoon. Called me up and said that he replaced the master cylinder again, bled the system, and still the same problem, but he also said he found the culprit. I said "great" after all the money I spent already. So that afternoon I went back to the mechanic. He said it was the front brake lines that were worn out and needed to be replaced; also suggested that I replaced the rear brake lines also. He even demonstrated his little "trick", he said....by turning the car on, clamp the brake lines with a clamp and told me to press the brake pedal. The moment he released the clamp, the brake pedal went soft and to the floor. We did this again to all the other lines and it exhibited the same result. Thus, he said to replace the brake lines and that should cure the problem. I told him I'll be back if it didn't. So again, I changed the brake lines myself and bled the fluid again. Test drove it....and....I was about ready to kill somebody right there. Same old soft pedal. So now, I've waisted roughly $500+ bucks and many hours on labor, bloody hands and all...and yet, same as what I had started with.

SUMMARY
Problem: Soft Brake Pedal

Changed:
-changed master cylinder
-changed front rotors, calipers, pads
-changed rear rotors, calipers, pads
-changed front and rear brake lines
-bled the brake system after each change

Result: Still soft brake pedal

If I go back to this mechanic, he's good as DEAD! so before I do that, I would like to see if anyone have had this problem before or know what I should do next to correct the problem. Any advice or opinions will be much appreciated. Thanks for reading my long post.

cashoit

brake booster maybe??

cashoit

check the FSM...there is a control valve at the brake fluid reservoir...that may be slipping.

If u have replaced pads, rotors, and lines...somewhere in the line somethin is not keeping pressurized. CHeck components that attach to the brake lines. If the line isnt remaining pressurized then the fluid must be returing to the reservoir. Since u dont have any leaks...something jus is NOT actuating

fignewtin88

weel when did this problem first occur , and how long ago is it alot softer than normal and is it all the time ?

One Post Wonder

iTrader: (1)

Sounds like that guy was just guessing at your problem and didn't do any diagnostic work. Check the linkages at the brake pedal and make sure nothing is loose. Also, the "mechanic" may not have bench bled the master cylinder before installing it. You may wish to do that yourself.

Nopike

iTrader: (2)

I just googled it
http://autorepair.about.com/od/troub.../ts_brakes.htm

Any hissing wooshing noises when you apply or bleed the brakes?

Brake Booster Test from FSM
ON-VEHICLE SERVICE
Operating check
* Stop engine and depress brake pedal several times. Check that pedal stroke does not change.
* Depress brake pedal, then start engine. If pedal goes down slightly, operation is normal.
Airtight check
* Start engine, and stop it after one or two minutes. Depress brake pedal several times slowly. The pedal should go further down the first time, and then it should gradually rise thereafter.
* Depress brake pedal while engine is running, and stop engine with pedal depressed. The pedal stroke should not change after holding pedal down for 30 seconds.

fignewtin88

yea i agree make sure to bench bleed the master cylinder and ..maybe the brake booster if it get hard when the car is off and extremely soft when the is on then is most likely the brake booster

imports_only1

Thanks guys for all your advises. I see that another member is having the same spongy brake pedal as me. I'll have to go look at the caliper bolts to see if they're sticking or not and check all the brake lines for any leaks. If everything checks out ok, it may be the brake booster. How do you bench bleed the master cylinder?

KRRZ350

iTrader: (29)

CHECK TO MAKE SURE THE CALIPERS ARE ON THE RIGHT SIDE.

Don't know if it's possible with any Maxima calipers (I should considering what I know about Maximas) But I had a similiar problem when I did a rear caliper on one of my customers '05 F250's. When I put the caliper in the parts store gave me the wrong side, and I never noticed because it bolted on fine even though it was for the other side, the only difference between the 2 sides was the location of the bleeder........... THE BLEEDER WASN'T @ THE VERY TOP! Just like you I ****ING KNEW it felt like air in the lines the entire time even though I knew that couldn't be.

I used the same trick your mechanic did to figure this out, when I blocked off the one I just replaced it was fine. I unbolted the calipers but left the lines on, put a block of wood between the pads, and held the caliper upside down while bleeding it. If the bleeder isn't at the highest point on the caliper you will always have air trapped @ the top of the caliper.

67whitegoat

iTrader: (4)

I agree with two former posters. I have run into that issue before. Brake Booster.

DC2Kris

I am having this same issue. 2000 Maxima. Put 2 new calipers in the rear. New pads and rotors all the way around. Bled each caliper in order atleast times now and still the same result. The pedal is rock solid with the car off but goes straight to the ground when the car is on. Also replaced the battery.

Anyone figure this out yet?

95franklin

You may have better luck in the 5th gen forum.

I don't mean to distract from the main topic, but I cannot find a single piece of information on changing brake lines. Is there a chance you could briefly describe for me the process? Would you recommend using the pre-bent/sized OEM lines or doing it yourself?

Thank you and best of luck.

ColombianMax

iTrader: (7)

I had the EXACT SAME PROBLEM on my g/fs 89 SE when we got it in 2006...

I replaced the exact same things you replaced except the brake lines.

Turns out that since we replaced the calipers and NOT the bracket along with guidepins... it slipped my mind to check the guidepins and they there frozen in there! So after tons of MC bench bleeding, bleeding at the calipers, and all the new parts. It turned out to be the guide pins. I just ended up getting new ones from the part store for about 13 bucks each. 4 years later and the thing stops on a time with nice pedal feel! Hope this helps cuz I almost gave up!

Do make sure that the calipers are all installed on the correct side with the bleeder valve at the TOP so there's no air trapped in there like it would be if the bleeder were on bottom

cashoit

So i did my brake job yesterday.

Someone please confirm something for me... on the brake bracket (nissan calls it the torque member), there is only ONE removable guide pin? This would be the top pin. The bottom pin is NOT removable?

Goomz

iTrader: (1)

the pins that have the rubber boot attached? there is two and they both are supposed to come out. my rears were a ***** to get out. i hammered one that was stuck and was able to free it, remove it, and put brake caliper grease all over it...and i put it in the hole the bolt was removed from. it operates smoothly now

Goomz

iTrader: (1)

try to heat it if you have a butane torch. pb blaster works waaaay better than wd-40 or anything else i have tried. but its flammable so i'd stay away from using both in a combo lol

bobflood

Cashoit: Both pins need to move for calipers to work properly. I had to replace a rear bracket last year because a caliper pin had frozen (and that was here is Georgia where rust is generally not a big issue.) Machine shop cracked bracket trying to get pin out.

cashoit

ok ok wait a sec...

I remove the wheel....i then remove the upper and lower bolts on the caliper...I remove the pads and clips.....then i remove the two bolts to remove the brake bracket.

The rubber boots on brake bracket....only the top pin was removable. the bottom pin wasnt TRYIN to come loose.

U guys are saying both the upper and lower are removable????????

DAMN!

I reinstalled everything and the car is braking fine. Is it that big of a deal. THe old pads did not show abnormal signs of wear like the top was wearing faster than the bottom.

Goomz

iTrader: (1)

yes they are and should be removed and re greased while the brake job was commencing

cashoit

Aight cool man.

Like i sd, that bottom pin was NOT tryin to come loose.

Ima replace the bracket.

good looks

imports_only1

Wow....I must have forgotten this thread since it has been awhile. But I was able to find the culprit. It was one sliding pin on the left rear caliper bracket. That one pin was frozen. After I changed the bracket with some new pins and grease, bled the system, the brake pedal was back to normal. I never went back to that mechanic again. One stupid little pin caused so much headache and money.

Cashoit.....you might not have any problems now with one stuck sliding pin but eventually you will. I advise to you change it now to prevent future headaches and more money spent.

Goomz

iTrader: (1)

wait u can try to heat it up to get it out! dont buy a new bracket just yet.

cashoit

Yo man...its only 20 bucks per new bracket from Autozone. Im jus gonna replace the bracket. Be done with it.

Im tellin u goomz, that bish was stuck! Im not waste my time with it. Replace it and be done.

New brackets, new pins. No worries. Yup.

Goomz

iTrader: (1)

oh werd thats mint! i didnt know they were so cheap

Sniperuml

I have the sample problem desicribed above, I replaces all 4 rotors and pads, rear two calibers were frozen so I replaced those as well. The brake pedal becomes hard as a rock when the car is off, as soon as you turn it on it becomes soft. From reading the posts above, should I look to bleed the brake boster or take apart the front two calibers and grease the guide pins? Thank you for all of your help.

ColombianMax

iTrader: (7)

The brake booster does not get bled - its vacuum operated..

You must be referring to the Brake Master Cylinder. Check the guide pins first -make sure every single one (All 8 -2 per wheel) pushes in and out of the bracket where the caliper bolts up to.

MKRD.info

I have the same problem. I will post about what I find. But slide pins were rusty. I did break them out and lubed them, but now I am going to replace them instead.

Regarding extracting frozen or rusted guide pins, I wrote an article on that:

How to extract a rusted or frozen brake caliper guide pin

I will keep you updated about my progress

Achomie