1991 240sx - loud banging after z32 brake conversion and 5 lug swap

[vvaffle]

I just finished my z32 brake conversion and 5 lug swap, including the rear emergency brakes and 17/16" MC. I bled the brakes and they feel fine but on heavy braking there is a very loud banging noise. The frequency of the noise is relative to my speed.

I can't figure out where it's coming from, it feels like it's from the front cause my feet vibrate, but it sounds like it's coming from the back. Anyone have any idea what it could be? It's quite worrying.

here are the parts I used:-front 5 lug conversion hubs,-300zx rear hubs, emergency brake assemblies and brand new z32 2+2 e-brake lines.-all 4 remanufactured 30mm aluminum calipers, brembo blank rotors and Hawk HPS pads-z32 NA rims with a 1/4inch spacer in front.

any ideas?

[vvaffle]

quick update and in case anyone searches: after the full break in procedure, the noise is significantly reduced. It's barely audible at all. The break in procedure I used is as follows:-10 hard stops from 60mph to 10mph.-5 minutes of going 50mph with as little braking as possible to let them cool-10 hard stops from 80mph to 30mph.-5 minutes of going 50mph with as little braking as possible.

[94_240sx]

Did you use e-brake cable extensions or not?

[positron1]

Any word on what that could be yet? I'm intrigued!

[94_240sx]

Any word on what that could be yet? I'm intrigued!

Same here. positronone, got the info on extension in the other thread. Thanks.

[positron1]

I just saw that, good info man, finally get to see those cables side by side too. I was getting confused for some time with R33 this and 2+2 that. You cleared that up well.

[vvaffle]

i didnt use the extensions. i just drilled into the floorpan to connect the front most mounting mount of the cable to the car. from the i just went straight to the wheels. I can take a picture if that doesnt make sense.

[jaxiss]

Did you ever figure out exactly what caused this noise? I'm about to start swaping my 92' coupe the same way. Maybe wheels barley hitting the caliper, or maybe the car has a factor abs setup thats not happy now?I'de like to know. Banging from the brakes shouldn't happen at all, and deffinitly not work its self out

[vvaffle]

Im fairly certain that it has something to do with the emergency brakes that I put on. the pads weren't in the best shape and weren't fully attached to their backing plates. on a good note, i cant hear the noise at all now and while my emergency brake is not great, it does stop me from rolling down a hill.

[94_240sx]

positronone,Do you remember these 2 different anchor bolts? He might have used smaller ones and it's causing this problem because there's a little play.

vvaffle,Can you tell us which one you used?
Modified by 94_240sx at 6:40 AM 11/23/2007

[positron1]

You know, I was thinking the same thing yes.

[vvaffle]

I'd have to take it apart to figure out what mine looks like, however the whole rear setup, e-brakes, and hubs is off the same 1991 300zx.

except the calipers are remanufactured aluminum calipers

[94_240sx]

I'd have to take it apart to figure out what mine looks like, however the whole rear setup, e-brakes, and hubs is off the same 1991 300zx.

except the calipers are remanufactured aluminum calipers

You got the wrong ones, so there might be a play. Sorry, I'm not 100% sure on it though, but only 1990 z32 came with thicker anchor bolts. You should double check and make sure there's no play. Check this thread.

zer...age=3

[positron1]

94_240's thread rocks as far as answering questions about the Z32 setups. It answered all my concerns when I was doing research before doing this conversion.

[vvaffle]

thanks for the suggestion. ill take it apart as soon as i have a day off work and its not freezing outside. im just not sure where the play would be since that anchor bolt goes through a 300zx hub. the only thing thats not off a 300 is the spindle.

[94_240sx]

im just not sure where the play would be since that anchor bolt goes through a 300zx hub. the only thing thats not off a 300 is the spindle.

Again, check the thread. This is page 2.zer...age=2

There's a gap like this...

So, anchor bolt moves left and right and you hear banging noise when it hits a backing plate. That's what we are thinking.

[jaxiss]

i justs did this same swap to my 92 coupe last night. as it turned out the 91 turbo 300zx i sourced my rear parts from had the same equipment pictured here. fortunatly i got the complete uprights with hubs and i actually cut the part of the hub that backs the e brake anchor off and put it in along with. this seems to work but havn't test driven yet because my agency power brake lines don't fit at the caliper right.