Bleeding Brakes. Disconnect the battery?

[CanuckQx4]

Hey guys, Iam in the process of getting my qx4 on the road after quite some time sitting. I am looking to do a brake fluid flush from it before this weekend. After reading some threads here and what I interpret from the FSM the battery needs to be disconnected before doing the bleed?

My truck is a 2wd so I dont have a load sensing valve, but I do have abs. Ive never done a bleed on an abs car before, do you still simply bleed at the 4 corners or is there more points to the bleed.

Thanks guys! Looking forward to putting the Qx4 back on the road and fixing the little problems that Im sure to have. Just did poly bushings in all the trailing arms this past week!

[Towncivilian]

I've bled twice without disconnecting the battery, I wouldn't bother. Just bleed in the correct order (LR -> RR -> LF -> LR). Our 2WD models don't have a load sensing valve, else we'd bleed that first.

[CanuckQx4]

Ok thanks, just need the girlfriend to be around to be the assistant I suppose.

I also remember another problem with this cars brake pedal, in the extreme cold, there was a slight air leak audible from inside the car, but went away when pushing the pedal, and only happened in the cold. I just remembered this by looking at my past posts.

Could this be indicative of a brake booster failing?

its not so cold out just yet and I havent had any seat time in the car, but i expect this problem to show its head shortly, just curious what I should inspect/replace

[Towncivilian]

The brake booster check valve could be sealing improperly in the cold weather. It might be worth replacing it with a new OEM part due to its age, plus inspection of the brake booster hoses is a good idea as well.

[Slumpert]

bleed in the correct order (LR -> RR -> LF -> LR)

How many LR wheels do you have? /Smile

[Towncivilian]

Ha, of course I meant this, assuming driver's side is left:

Left rear brake
Right rear brake
Left front brake
Right front brake

[CanuckQx4]

The brake booster check valve could be sealing improperly in the cold weather. It might be worth replacing it with a new OEM part due to its age, plus inspection of the brake booster hoses is a good idea as well.

Ive been trying to find a good diagram to see exactly what part could be even leaking air/vacuum that is relative to the brake pedal being pushed but didnt have any luck.

On my back with my face in the pedal assembly its hard to see anything that would cause the small, yet very audible leak.

[Towncivilian]

The brake booster valve is part of the brake booster vacuum tubing in the engine bay. Look on BR-25 of the FSM for a diagram.

[CanuckQx4]

What year car FSM are you referencing from Town, BR25 in the 2001 Qx4 fsm for me is about squeezing the front brake caliper, no brake pedal diagram. Just trying to see what youre seeing

[Chuck Tribolet]

At least for the PF, there are two different 2001 FSMs. One is for the 2001, the other for 2001 + 2001.5.

Chuck

[Towncivilian]

2001.5 is the one I keep on my phone which is where I looked up the page I mentioned. Sorry, I should've specified, I assumed the page number would be the same between the two FSMs.

[CanuckQx4]

No its cool I appreciate your guys expertise! Just trying to see what you see. I dont see a 2001.5 on Nicoclub FSMS so I'll do some scouring to try and find one elsewhere

[Towncivilian]

http://www.nicoclub.com/FSM/Pathfinder/ ... athfinder/