Pathfinder brakes are soft! Whats up?

[TuffguyF4i]

I did a front brake job on my Pathfinder. In order to get the pads back in, i had to bleed off a small mount of brake fluid. They just would not go back in. So, no problem, just re bleed. Well i rebled ALL of the brakes and even used a vacum bleeder, and still cannot get them to really hold good pressure. The truck does stop fine, but the pedal feel is not what it used to be. I also feel like i could not skid the tires even if i tried. The nipples are at the high spot on the caliper, so fluid will not drain out letting air in,,looks like a good design.

My friend is a mechanic, so we had the truck on a lift and the process we used was this.

-bleed the front (hand)

-bleed the back (speed bleeder)

-bleed the front again (speed bleeder)

-crack the fittings at the master cyclinder under pressure...no air.

-adjust the play in the back brakes,,they where fine.

We went through about 1 quart of fluid, which was all the truck had in it.

We where getting ZERO air bubbles. Is it possible a gasket was damaged in the master cylinder? I have never taken one apart, so i'm speaking from ignorance.

No leaks found anywhere. Checked the whole system.

Thanks for any help.

Dave

[Furbird]

You're supposed to go back to front. I would suggest having a brake flush done, where they use a machine that sucks the fluid out. It eliminates air bubbles and also replaces all the fluid with new stuff. I had this done on my van and it made a world of difference just with the fluid swap.

[redxxrdr]

Rule of thumb is to bleed the wheel most distant from the master cylinder first, then work closer.

You said pads, so is the Pathfinder 4 wheel disk? Poorly adjusted rear drums will do the same thing.

Is there any possibility that the master cylinder was run dry during bleeding? I did that on my F150 once and could not get it to purge. I had to take the master

off and bench bleed it first then reinstall to get all the bubbles out. Possible, but doubtful that the master cylinder seals are leaking. That is as long as the proper

brake fluid was used. ( don't ask how I know that one ).

If all else fails, find a local shop with a power bleeder and get them to do it. The cost involved is minimal if this is a primary driver.

[Zero Knievel]

I did a clutch job where it just took a while to get used to the new feel, but it worked fine. Some systems need time for the pressure to build up to what it was before you flushed the system.

[TuffguyF4i]

You're supposed to go back to front. I would suggest having a brake flush done, where they use a machine that sucks the fluid out. It eliminates air bubbles and also replaces all the fluid with new stuff. I had this done on my van and it made a world of difference just with the fluid swap.

I understand that. The reason i went front, then back, is because the front was the only section opened and only opened for a second. This started as a pad swap and turned into a brake job.

Zero..

I did this job about 1 month ago...hoping it would get better and it hasn't. Looks like i'll have to get a real pro to look at it and bring back my pedal feel!

[jon haney]

Did you use new Nissan brake pads?

I put some cheap pads on my wife's Altima one time and got the same spongy feel you described, and I never touched the fluid. After 10K of fading, stinking, dusting, and squeaking, I replaced with Genuine Nissan pads and it was like a whole new car.

[TuffguyF4i]

Did you use new Nissan brake pads?

I put some cheap pads on my wife's Altima one time and got the same spongy feel you described, and I never touched the fluid. After 10K of fading, stinking, dusting, and squeaking, I replaced with Genuine Nissan pads and it was like a whole new car.

No i didn't....i used some pads that where about $40 from autozone. Not the cheapest, not the most expensive.

Thats interesting though...strange.

[Zero Knievel]

Manufacturer pads don't mean squat...or they shouldn't. Nissan (etc.) does not make them, they have someone make them to their specs. It is possible to get aftermarket pads that don't conform to OEM specs, which is why you take your originals and compare them to what you are buying....just in case.

If your brakes work as well or better than before, I'd say it's in your head. If you notice no improvement, then I'd say do a total system flush. It's not rocket science, and that should get all air out of the system. I can't see how a properly done flush won't get all the air out of the system. Double check your brake pads to ensure they are put in correctly and that they match the OEM ones. It is possible you bought the right pads (marked on box) but the contents were not right (seen that happen too).

FWIW, is there any chance you got air into the master cylinder? With brakes, it shouldn't be hard to fix that problem, but I had this happen to the clutch (which had it's master cylinder mounted at an angle), and getting that air bubble out was a total bitch.

[97xxca]

If your brake pedal feels like it travels down after initial stop, the master cylinder might be bypassing internally.

IF the pedal stays up then you have air in the system.

[TuffguyF4i]

If your brake pedal feels like it travels down after initial stop, the master cylinder might be bypassing internally.

IF the pedal stays up then you have air in the system.

I should have clarified initially,,,thank you.

The pedal goes down farther than it should. With the car running (power assist) i can't build pressure. The pedal yields resistance but not what it used to.

That is what led me to believe i had some sort of internal master cyl. leak.

My wife was initially helping me do the first bleed before i took it to my friends garage. I think she might have gotten really on the brake pedal and put it right to the floor a few times. I have heard that itself can damage some seals since its a bit of an over travel situation. But i don't have anything to back that up.