I just turned my rotors and upgraded my brake pads to semi-metallic ones from the Autozone. Now, my brake pads feels spongy. The mechanic who turned the front rotors' told thickness is within specs. I don't think that I got air in the brake lines when I pushed brake piston in. One mechanic told me that I may have expanding lines which may cause the problem. The other told me that I may need a new master brake cylinder because I have 108k on my 97 max. I also read post by a member that said that if you push brake pedal all the way to the floor, it may cause a piston in the master brake cylinder to get in the rough area and thus get damaged. A few days before that I replaced my valve cover and exhaust manifold gaskets, but I don't think it has anything to do with it. I checked my brake booster it seems to work fine. Does a combination of a turned front rotors and new brake pads cause such problem.

Thanks

 

did you put the pads on yourself?? Is this the first time you experienced this?
the pads might not be seated on right with the caliper. check to see if your lines have a leak. You might need to re-bleed the lines. If your master cylinder were to go bad (which they tend to do over time but not that often) you would of noticed it before you had the rotors turned and the new pads on...

 

I changed my brake pads several times before. Never before had such a problem. Blead the line 2 times. Still have the same problem. I do not see any leaks comming from the lines. Pads seem to be properly placed. Very strange!

 

Bleed the brake system and it will be much better

 

highly doubt it is the master cylinder. one way to tell if it is the master cylinder is to press the brake and hold. if the pedal drops to the floor (even slowly) you know your master cylinder is shot. It is prob time for a line change anf fluid flush.

 

^^^^^ i agree new lines n flush

 

I would do the easiest and cheapest first and get a one-man bleeder kit from autozone for 6 bucks and bleed the brakes.

 

or how about you not go to all that trouble and first try to pump the brakes with the car off....Most people forget that step after they are finished. So the piston can be pushed back out.

 

get stainless steel brake lines.....and flush your system! might as well put some dot4 brake fluid for withstanding higher braking temperatures. but yea, if you just now had changed the brakes, let them brake in, also pump em up if you havent....to let the piston push back out

 

If he had time to feel it and call 2 mechanics it wont "pump up" anymore than it already is. if you have to step on the brake more than about 3 times to get the piston where it should be, there is a problem.

 

SPONGY = Air In Lines

Bleed em dont think id jump on ordering master cylinders or ss brakelines right away lol

 

I already blead my lines on each side 2 times. I may possibly have 2 stuck pistons because my front rotors still look freshly turned and not shiny after 2 weeks of driving. But I don't think it would cause my pedal to be spongy. When my car is not running, the brake pedal feels solid. Is it possible that I may have over pushed my brake pistons in thus damaging them?

 

But if the car is running then it wont effect that. the car needs to be off so you can manual pump brake fluid in to push out the piston.

 

I doubt you damaged them but if the car has over 100K on the original brake calipers you may consider changing them with rebuilt ones, especially if you plan on keeping the car for a while.

 

what kind of brake fluid did you use??

 

get some SS lines and flush out ya brake system. Put some fresh fluid in there.

 

The problem is you only bleed two lines. You need to bleed all of them properly starting from the right rear, left rear, front right, then front left. Use a vacuum pump bleeder. Use a whole Liter of fresh fluid. This should do the job. If it doesn't do the job check your sliding pins and your caliper to see if they are frozen.

 

My friend, a mechanic, bled the lines in the order that you described. I had a frozen caliper in the rear once, boy was rotor glowing. I don't think a frozen caliper will make my brakes spongy, it didn't last time. I'll try to replace my master brake cyl. on Fri. I'll also drain old and put in all new DOT4 fluid in the system. I'll just be extra careful not 2 scratch the new M.B.C., so i can take it back 2 auto zone if it wasn't it.

 

i have always bleed them cross ways/X pattern (right front, left rear, right rear, left front). I know that with abs it is like that to properly bleed the lines right., but i just have always been doing my brakes that way. is there any known difference bleeding the brakes without abs via front, front, back back?

also....i have heard about this not sure how "lagit" (yes i know old 90's term bein thrown out) it is....but adding dot4 can cause brake lines to corrode/rubber to break down alot quicker when mixed with existing dot3 in the brake lines, or any residue? IF you are switching to dot4 you will need to remove all brake fluid in lines and resevoir? I understand the concept that clean/new fluid is well clean/new fluid....but lets face it there are some ppl who would rather take the short route for quick gains, than the longer route with pure investment purpposes.

Like i said someone told me this, so dont bust my ***** on this one guys.

 

I guess I'll stick with DOT3.
I was also told that DOT3 fluid is hygroscopic and that DOT is not.

 

Stainless lines make a huge difference in pedal feel, well wort the the cost. I had my mechanic install them and do a complete system flush with no problems. Sometimes its worth paying someone to do things right.

 

Well, I installed new master brake cylinder. Did not solve the proble. Installed Magnum steel reinforced brake lines. Blead brakes 3 times, still have spongy brakes that do not lock up. I have no idea guys what can be happening.

 

One of your slide pins cold be sticking also.

 

this was a problem on brakes i just did that felt spongy. i put in new pins and lubed them with hi-temp caliper grease and the problem went away. so check all of the pins to find the problem. good luck

 

A while back I had pins that seized on my rear caliper. It caused my caliper to go up in smoke every time I drove. Once I re-lubed the pins everything went back to normal. I will take my caliper apart and re-lube the pins. But I don't think that seized pins on one wheel would affect all four wheels. I gave my good friend, who is an ASE cert. mechanic, a full schematic diagram of maxima brake system and hopefully he will find what's wrong with it. I bled my lines like 5 times now.