aallbbeerrttttt

i recently purchased a 1990 240sx SE with ABS i believe

the brake pedal feels REALLY soft, i can push it all the way down to where it stops and i get very little braking power

i checked the fluid and i filled it up till max, and it's still the same

now i'm thinking it can be either a faulty master cylinder or needs new pads

also, not sure if related, but sometimes when i'm driving or engine braking, i hear metal hitting something, sounds like a loose heatshield, but my friend says it's coming from both sides, so i think it's something with the brakes

i'm going to take the pads out and see how bad they are, and if they're still good, i hope i can conclude it to the master cylinder being faulty

Levi SPL S14

Try bleeding the system. The brake lines are 16 years old they are old and worn, perfect time to replace with SS.

Check the pad first. You dont need to pull off the caliper to see the pads. Just pull off the wheel and wha la. Replace if necessary.

It could either be a loose heat sheild on the ex. manifold or the one under the car. Check the bolts, they will be rusted have a can of PB Blaster ready.

You really dont need to take them out. Dont work harder if its not needed.

Levi

l2aine

^ agreed if it's really squishy it's pointless to check pads because worn pads will do something else OTHER THAN make the pedal feel like you're describing.

aallbbeerrttttt

me and my friend's are gonna bleed the brake lines when the weather gets better..it's raining non-stop here and i dont have a garage to work in

just wondering, how do i check the pads without taking off the caliper? i always thought i had to take off the wheel and take off one bolt on the caliper, then swing it up and take out the pads..if there's a technique where i dont have to take it apart, LEMME KNOW haha

nsn240

^just look at them... you can see the pad/rotor very easily...

aallbbeerrttttt

well i was driving it today, and i found out if i pumped the brake pedal 2-3 times, i can get pretty good pressure onto the pads/rotors..so now i'm thinking it's air in the brake lines and i need to bleed them

anyone got a tutorial or DIY on how to do so? i never done it before, and i'm probably gonna do it with another friend

aallbbeerrttttt

i tried bleeding the brakes today and no good, the brake pedal wouldn't even pressure up when the bleeder valve was closed

no matter how many times i pump the brake with the keys out of the ignition, the brake pedal doesn't get firm, i'm 100% positive that the brake pedal should be firm when the car is off and the brake pedal is pumped 2-4 times, but it's not doing it at all, it feels the same once i release

so now i'm thinking 2 things, bad brake master cylinder or brake booster

what do you guys think i should do, how would i be able to test the BMC or the BB to see which is the real thing that's messed up

do you think it could be something else also?

twofourtyesex

are you bleeding correctly?

remember, always start with the wheel furthest from the master cylinder, (rear passenger). then go to rear drivers side, then front passenger, then front drivers side.

have your buddy pump the pedal, all the way in all the way out, like 5 times, then release the pressure on the bleeder. be sure to repeat the

"pump, release pressure, tighten bleeder, pump" cycle enough times on each wheel until the pressure release sprays only liquid, NO AIR CAN COME OUT! maybe this helps, maybe not but i tried. good luck anyway.

aallbbeerrttttt

yea we used the proper procedure to bleed the brakes, and with the car off and key out of ignition, the brake pedal doesn't firm up when pumped multiple times and it sinks all the way into the floor time after time, i'm not brake guru, but to me, that sounds like a broken master cylinder

we started bleeding from the passenger rear wheel, but there was so much air coming out and it still wasn't pressuring up, something was definetely wrong

it's ok, i ordered a new brake master cylinder, front/rear pads, front/rear rotors, plugs, wires, oil filter, oil, drain plug, and air filter

i'm going to put all this stuff in at my friend's shop and he has these speed bleeder things that you put on the bleeder valve, supposedly it's a one man job and it doesn't allow any air in at all, if all else fails, there's a midas next to his shop, i'll just pay for the job done right

twofourtyesex

well it seems like your all set. i would say the master cylinder also, but i am not a brake guru either. good luck.

Ron Smith

Any leaking brake cylinders? If not, agree it is probably brake master cylinder. Worse yet, brake booster. Master is fairly cheap.