Brakes...

ONLY for ADVANCED technical discussion about the 240sx!
Crunkrich
Posts: 1584
Joined: Wed Jan 18, 2006 3:35 pm
Car: 1992 Nissan 240SX (R.I.P.)
2000 Cherokee Sport 4x4
Contact:

Post

I jus finished changin the back brakes (rotors pads calipers) last night and I can't get the brakes bled properly for the life of me, or so it seems. I bled all four brakes and was getting solid fluid no air bubbles so I don't know what the problem is.

When pumping the brakes, the pedal is hard when the car is off, but when the car is on and the booster gets vacuum its a soft pedal. The car stops, but doesnt come close to locking the brakes up. Possibility that the brake master is shot?

p.s. I changed the fronts about 3 months ago (rotors pads calipers) and didnt have a single problem with it


User avatar
ricebike
Posts: 3381
Joined: Sat Feb 15, 2003 7:03 pm
Car: 1989 240sx se 5spd (donated to my brother in law)
2002 Quest
2005 Altima
Location: CNJ

Post

this just happened after u fiddled w/ the rear brakes???

retrace your steps...

put the car up on jackstands... hmm, start the vehicle n put it in neutral... spin the wheels by hand & have someone step on the brake pedal... to see if the rear tires stop spinning...

idk what else to tell u; check the one-way vaccuum valve on the hose before the booster?

but, r u sure you've bled the system of air??? i know when i had no helper in bleeding my front brakes after i changed them out w/ new hoses n calipers, i did this trick called gravity-bleeding & it worked for my non-ABS equipped car

User avatar
jdm_master_X
Posts: 3518
Joined: Sat Jul 23, 2005 6:22 pm
Car: 92 Nissan 180SX LHD!...LaWL
Contact:

Post

are you bleeding the system in the correct order?

the order is typically the wheel furthest away from the BMC. in this case, its RR, LR, RF, LF.

i would check if your booster is filled with fluid. that means the seal from the master is shot. time to rebuild, replace, or upgrade to a z31 or z32.

Crunkrich
Posts: 1584
Joined: Wed Jan 18, 2006 3:35 pm
Car: 1992 Nissan 240SX (R.I.P.)
2000 Cherokee Sport 4x4
Contact:

Post

I've been bleeding the brakes correctly, and the booster has always had enough fluid in it, except once which I think was the time it allowed sediment to get into the cylinder itself.

My buddy is hookin me up with a spare booster, hopefully that will solve the problem. I'll update this in the next day or so when I know whats goin on, thanks for the help so far.

User avatar
jdm_master_X
Posts: 3518
Joined: Sat Jul 23, 2005 6:22 pm
Car: 92 Nissan 180SX LHD!...LaWL
Contact:

Post

Crunkrich wrote:I've been bleeding the brakes correctly, and the booster has always had enough fluid in it, except once which I think was the time it allowed sediment to get into the cylinder itself.

My buddy is hookin me up with a spare booster, hopefully that will solve the problem. I'll update this in the next day or so when I know whats goin on, thanks for the help so far.
the booster shouldnt be filled with fluid. only the master cylinder should be filled.

Crunkrich
Posts: 1584
Joined: Wed Jan 18, 2006 3:35 pm
Car: 1992 Nissan 240SX (R.I.P.)
2000 Cherokee Sport 4x4
Contact:

Post

jdm_master_X wrote:
the booster shouldnt be filled with fluid. only the master cylinder should be filled.
typo, oops


Return to “240SX Technical Forum”