Brake pedal feel weird

[jetstream87]

So lately I been noticing that when I press on the brake on a stop light the pedal is pretty firm but then I can feel it go in more and more in, times I slam on the brake to stop the car from rolling. This been going on for the past few days in which I added some brake fluid and still the same thing. I notice this morning that I have to press lightly on the brake in order to make the pedal firm again. What can be this problem?

[smj999smj]

If you're adding fluid consistently, there is likely a leak somewhere in the system. If you are not losing fluid, then it sounds like your brake master cylinder is failing. The thing to do would be to thoroughly check your brake system for leaks, including taking off the rear drums to inspect the wheel cylinders, hoses, calipers and metal lines. It's a good time to adjust your rear brakes shoes while you are there. If all of this looks good, then I would replace the master cylinder. If you are doing it yourself, make sure you reference the factory service manual for the proper bleeding procedure, because not all Nissans are bled from the furthest to the closest, in order. Rockauto.com is usually a good place to get parts for a great price and they have a great selection.

[jetstream87]

If you're adding fluid consistently, there is likely a leak somewhere in the system. If you are not losing fluid, then it sounds like your brake master cylinder is failing. The thing to do would be to thoroughly check your brake system for leaks, including taking off the rear drums to inspect the wheel cylinders, hoses, calipers and metal lines. It's a good time to adjust your rear brakes shoes while you are there. If all of this looks good, then I would replace the master cylinder. If you are doing it yourself, make sure you reference the factory service manual for the proper bleeding procedure, because not all Nissans are bled from the furthest to the closest, in order. Rockauto.com is usually a good place to get parts for a great price and they have a great selection.

Came to figure out that it is not a leak in which I have the master cylinder pump on its way. There are times where it brakes good and other it will not. I was researching on how to bench bleed the master cylinder in which some actually say that if you bleed it properly you do not have to bleed the system since all the air is out. I am going to do a homemade bleed system in which I hope that the bleeding valve is a 1/4" to connect the tube.

[smj999smj]

You need to bench bleed the master cylinder before you connect it to the brake lines of the vehicle. Afterwards, the entire brake system should be bled at the wheels following the manufacturer's bleeding procedure. This is because once you disconnect and reconnect the brake lines from the master cylinder, there is the potential to get some air into the brake lines. Also, it is a good idea to flush the old fluid out of the lines, anyway, to rid the system of any moisture that may be in the fluid due to normal condensation.

[jetstream87]

You need to bench bleed the master cylinder before you connect it to the brake lines of the vehicle. Afterwards, the entire brake system should be bled at the wheels following the manufacturer's bleeding procedure. This is because once you disconnect and reconnect the brake lines from the master cylinder, there is the potential to get some air into the brake lines. Also, it is a good idea to flush the old fluid out of the lines, anyway, to rid the system of any moisture that may be in the fluid due to normal condensation.

I am going to do that now that since I rather have new fluid in the system and not old. From what I came to research the patter is Rear Left, Rear Right, Front Left, then Front Right.

[smj999smj]

According to the Nissan service manual for my 2006 Pathfinder, it's as follows:

-Rear Right
-Front Left
-Rear Left
-Front Right

That's for a US model with left-hand drive. If you have right-hand drive, it may not apply.

[jetstream87]

According to the Nissan service manual for my 2006 Pathfinder, it's as follows:

-Rear Right
-Front Left
-Rear Left
-Front Right

That's for a US model with left-hand drive. If you have right-hand drive, it may not apply.

I came across the service manual and it does indicate the pattern I mentioned above (US model) looking forward on changing the pump and bleeding the system, hopefully it stops raining here in California

[smj999smj]

According to the Nissan service manual for my 2006 Pathfinder, it's as follows:

-Rear Right
-Front Left
-Rear Left
-Front Right

That's for a US model with left-hand drive. If you have right-hand drive, it may not apply.

I came across the service manual and it does indicate the pattern I mentioned above (US model) looking forward on changing the pump and bleeding the system, hopefully it stops raining here in California

Yes, you're right. I forgot I was posting in the R50 section and not the R51!