brake bleeding problems

[Snackman508]

i took my calipers off to paint them. when i put them back on i swapped some brake pads that i had with more life on as well. i bled them all out. but they will not engage until i have it to the floor, before as soon as i would hit the peddle they would start to grab now, its mushy. its an s14 with 300zx brakes and the 240 master cylinder. rebled every thing 3 times now and no difference. pulled all the the lines and plugged the holes on the MC and the peddle would not move i im thinking its not a bad MC. could i have air in the calipers or some thing. help

[compactfean]

sounds like you still have air in the lines or calipers. Id tap yhe calipers with a wrench to get the air to the top and rebleed. I noticed that the 300zx brakes are harder to bleed than the 240 brakes....just take your time and bleed bleed bleed again.

[nando]

might also be you let to much fluid out of the master cylinder and there is still air in it. you might have to bench bleed the MC

[Warped161]

You may also want to get some speed bleeders, makes life a whole lot easier. they dont let air back in when you lift your foot off the brake pedal.

[moso]

pedal hight is determined by how fast the calipers fill, if your rear brakes are not adjusted correctly they will take forever to contact. cycle the parking brake to adjust. re-bleed.

[compactfean]

pedal hight is determined by how fast the calipers fill, if your rear brakes are not adjusted correctly they will take forever to contact. cycle the parking brake to adjust. re-bleed.

Z32 brakes are cable driven for ebrake that run the ebrake shoes...they have no affect on the hydrolic system.

[spank044]

i swapped some brake pads that i had with more life on as well.

I am willing to say that your problem may be the pads. You have groves in the pads you took off, groves in the rotors, and groves in the pads you put on then. These groves are fairly fine, but in the terms of contact area they are huge. Now if the crests and valleys on the rotor do not line up with the crests and valleys on the pads you put on then you have a very small amount of contact surface. Did you rough up the rotor or flat sand the pads before putting them back together. If not the pads have no way to break in on the rotors. Try pulling the rotors back off and hit them with a 80 grit pad on a grinder, just enough to knock down the high spots and put a swirl pattern on them. Then put a piece of sand paper on something flat and do figure eights with the pad until the glaze is gone. Reassemble and do 30 mph firm stops about ten times.

[compactfean]

^ what? He has a low mushy pedal....what are you talking about? Anyways, are your calipers backwards? bleeders should be on top....ive seen that before, where bleeders where on the bottom from the calipers being switched....either way......low mushy pedal Is a fluid related problem.

[spank044]

low mushy pedal Is a fluid related problem.

Most of the time yes, but not always. I am going on the OP knowing how to bleed brakes and he said the master is good until he has the lines hooked up. If the rotors and shoes on the rear are glazed and not seating properly the slip between them feels like a mushy pedal. Also if the park brake cable is over adjusted the brakes won't feel right. I've had customer vehicles come to me before with mushy, low pedals, high solid pedals, and variations in between. They usually have one common factor, the owner installed new shoes/ pads their self and did not break the glaze or groves from the old pads/ shoes. Then when they install the new pads they never seat/ break in properly and then glaze the pads or else the pads glaze on the high spots and never touch the low spots. That's why you shouldn't just install pads without prep work on the rotors. So I was just giving an alternate possibility to his problem, but since you know everything about hydraulic brakes I will humbly bow down and worship the very ground you walk on compactfean. Also I don't believe the Z32 brakes can be installed backwards because of the mounting position on the bracket.

[SilviablhS14]

I had the same problem once...turned out that I had the calipers on upside down. Make sure that the bleeders are on the top and not the bottom.

[spank044]

I had the same problem once...turned out that I had the calipers on upside down. Make sure that the bleeders are on the top and not the bottom.

So the Z32 brakes can be installed on the incorrect side?

[compactfean]

Yes and they will even still say nissan the correct way...only difference when the're backwards is the location of the bleeder. Also the z32 brakes do not have drums in the back so there isnt any adjustment that can be made to help unlike a shoe style rear brake, that by adjusting shoes closer to the drum, making the wheel cylinders work less will stiffen pedal hight. The z32 ebrake is %100 a stand alone unit. Meaning there is nothing that touch the regular braking system exept for the rotor. This is not your lever and plunger style ebrake where the cable goes to the caliper (oem 240sx calipers are like this)

So with there being absolutely nothing to be able to adjust on the REGULAR z32 brakes, 2 completely uneven surfaces are not going to make his pedal go all the way to the floor before grabbing. Bow to me or not....i asked you what you where talking about, you explained but still would not make any sense because we are talking about pedal hight, uneven surfaces,yes, can give you a "mushy" pedal until the 2 surfaces mate, even a pulsating pedal. Not a pedal to the floor.

[spank044]

2 completely uneven surfaces are not going to make his pedal go all the way to the floor before grabbing. Bow to me or not....i asked you what you where talking about, you explained but still would not make any sense because we are talking about pedal hight, uneven surfaces,yes, can give you a "mushy" pedal until the 2 surfaces mate, even a pulsating pedal. Not a pedal to the floor.

It certainly can. Neither of us know the exact condition of the pedal or the height of the pedal. When he stated originally that in order for them to grab he has to have the pedal all the way down. I took that as pushing as hard as he could before they locked up, that is how I perceived it. From that point of view the surfaces could be slipping on two glazed faces and require full pedal travel to cause them to lock up. We don't know what kind of pressure is required to push the pedal to the floor or the exact amount of travel. So you need to stop correcting me on someone else's problem, let the OP fill in the missing details since you don't know the circumstances. I understand how the Z32 brakes work, I was unsure of the mounting.

[compactfean]

I gotcha, well see what happens.

[Promise Land]

I did them upside down the first time and had the same "mushy" results.