# soft brake pedal x-trail T30



## nurseryman (Sep 12, 2018)

I have a soft brake pedal with the engine running, Have already replaced all pads and disc`s plus changed fluid. It has been mentioned that the ABS should need bleeding? How is this done please ?


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## rogoman (Dec 16, 2004)

You probably have air in the hydraulic system. This bleeding procedure was taken out of the FSM; it's a two person operation:

Bleeding Brake System

CAUTION:
●
While bleeding, pay attention to master cylinder fluid level.
●
Turn ignition switch OFF and disconnect electrical connectors of ABS actuator and electric unit
(control unit), VDC/TCS/ABS control unit or battery cable at negative terminal before working.
1. Connect a vinyl tube to rear right brake caliper bleed valve.
2. Fully depress brake pedal 4 or 5 times.
3. With brake pedal depressed, loosen bleed valve to bleed air in brake line, and then tighten it immediately.
4. Repeat steps 2 and 3 until all of the air is out of the brake line.
5. Tighten the bleed valve to the specified torque. Refer to front disc brake: BR-25, "Components" , rear disc
brake: BR-31, "Components" .
6. From step 1 to 5, with master cylinder reservoir tank filled at least half way, bleed air from brake hydraulic
line bleed valves in the following order:
Rear right brake→Front left brake→Rear left brake→Front right brake


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## quadraria10 (Jul 6, 2010)

Hi Rogoman,
A quick question about that sequence. I was under the impression you went from the furthest from the master cylinder to the nearest --so that the sequence would be Rear right, rear left, front right , front left. Now I am confused as we would bleeding the furthest the far right, and next the closest the front left, then the second furthest the rear left followed by the second closest the front right. Why would the manual suggest the order they do???


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## quadraria10 (Jul 6, 2010)

May as well answer my own question-- The sequence I mentioned earlier is for vehicles without a diagonal braking system.
From Quora
"Diagonal braking is another name to the x-split braking system (upto my knowledge). In this system the master cylinder has two outlets which are connected to two brake lines carrying brake fluid. One of these lines connects the brake callipers or drums of the front left and rear right wheels, while the other one connects the front right and the rear left tyre. As it connects wheels in diagonal position and brake lines somewhat form an X, they are called as X split brake system or Diagonal brake system. The advantage of this over the normal front rear split system is that whenever if one brake line fails you still have one of your brakes on the driving wheel working. Where else in front rear split suppose you have a front wheel drive system and front rear split brake line. Now if the front brake line fails you cannot handle the drive wheels.


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## rogoman (Dec 16, 2004)

While paging thru the various FSMs for different Nissan models/years, I noticed how the bleeding sequence varies for various models/years from what I posted here to the one you mentioned. The majority of master cylinders have two outlets, some older ones have three. What is probably the important factor in the bleeding sequence is the design of the ABS unit; some are rather complex. With the increasing complexity of brake system designs, it's best to follow the FSM documentation for a said model/year vehicle.


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