300zx brake swap issue, bolts too long

[Koukiii]

Hello guys,

I'm having a problem that I haven't heard about in various 300zx brake swap threads. I also searched and couldn't find anything on the issue.

CAR: 97' 240SX AUTO

Bought 300zx 30mm aluminum calipers that came with slotted rotors and the caliper bolts. Using the supplied caliper bolts with washer, the bolt threads through the entire caliper and comes out the back and hits the backside of the rotor.

I then tried using my stock caliper bolts which are shorter than the supplied bolts but they still are too long and I run into the same issue.

Only thing I noticed now away from the car is I put the caliper on with the bleeder screw facing down and read its supposed to be up. Even though I mounted the caliper on the wrong side I still see myself running into the same issue.

Seems my only option is to cut the bolt down for clearance but having never heard of this problem I want to make sure I'm not doing anything wrong.

Any ideas please let me know. She's my DD and I'm screwed until I can get the brakes working.

Thanks!

[russianphil18]

mounting the caliper upside down is bad for bleeding but other than that it should mount the same so thats not ur problem

you can find the correct length bolt to buy but it doesnt sound right that its too long. can you attach a picture?

I am about to head home for lunch and i have my caliper bolts off the car right now anyway so i will measure the length of mine which work fine

[Koukiii]

mounting the caliper upside down is bad for bleeding but other than that it should mount the same so thats not ur problem

you can find the correct length bolt to buy but it doesnt sound right that its too long. can you attach a picture?

I am about to head home for lunch and i have my caliper bolts off the car right now anyway so i will measure the length of mine which work fine

Hey man thanks for the reply and help on the matter!

I unfortunately don't have a picture with me as I am at work. I would assume the extra thickness of the rotor is what is causing the problem.

Using my stock bolts and washers, it just barely scratches the rotor but that's only hand tight. torqued down would make it hit a little more.

I went to a couple different places and they didn't have the bolts I needed.

[russianphil18]

i have gts-t calipers on an s13 these are my bolts. it all fit up right, with the 30mm thick rotors. mine are just a bit bigger in diameter than yours

http://i.imgur.com/TcF7qWZ.jpg

http://i.imgur.com/cxWIzi9.jpg

[Koukiii]

i have gts-t calipers on an s13 these are my bolts. it all fit up right, with the 30mm thick rotors. mine are just a bit bigger in diameter than yours

http://i.imgur.com/TcF7qWZ.jpg

http://i.imgur.com/cxWIzi9.jpg

Thanks for the pics homie I will compare when I get home and see whats up.

[schrapnel85]

This problem happened to me as well...I ended up using some washers and worked for me. Good luck

[loosesocksdiff]

what he said ^^^^ use two washers

[Koukiii]

Well its good to hear I'm not alone as I was doubting my install as easy as it's supposed to be... I wasn't fond of the double washer fix so I threaded the bolts through the caliper off the car and cut them down a few threads with a thin blade grinder.

I did this so upon removal from caliper, the caliper threads would clean up the cut bolt's threads. This solved the problem but of course when going to bleed the system the rear driver caliper bleeder screw is seized to the caliper and stripped on the flare nut wrench I was using to take it off.

DD still down :(

[russianphil18]

weld a nut to it and impact it off. then of course replace the bleed screw

and next time you cut a bolt i would suggest buying a nut instead of using the aluminum caliper to clean the threads. anyway good luck man, i hate having stuck bleeder screws

[zombiewolf513]

If you cut down a bolt, you should thread a dye onto the bolt first, so you can chase the threads on the end you cut when you take the dye off

[russianphil18]

most people dont have dyes laying around as theyre expensive, and I wouldnt want to leave the die on the bolt while grinding. its just as easy to chase the threads after the bolts been cut.

with a die you always want to use oil but if your cutting the bolt with a power tool then ur have a chance of igniting the oil...so better to use oil and a die after the cutting process...

anyway glad you got the bolt done and enjoy those brakes they make a world of difference

[Koukiii]

Thanks guys for the help! I like the idea of welding the nut onto the bleeder, I'll have to try that.

Got desperate and bled the front brakes only to see how it would work since the rears should still have fluid in them. Turned out ok. Pedal is squishy till half way but works fine past that. I'm sure that's a combo of stock BMC and unbled rears.

Rear brakes were warm after a short drive so I figure they are somewhat working. Front brakes lock up the wheels If I want them to. Sadly the setup isn't better than stock yet. Looks F'in great though lol.

I'm gonna save up some cash so I can finish the swap properly with z32 BMC, rear stainless lines, and maybe even reman'ed rear calipers so everything is fresh.

thanks again!

[russianphil18]

i got a BM57 from autozone round $50 after core exchange

you may be lucky and get the third fitting already in there (you care if you dont have abs). If you dont have the fitting let me know i machined a few inserts that work and convert the inverse flare to a flare without any modification. I will post it on the market place in a month or so whenever my account is old enough to post there.

im sad to hear that the brakes dont feel much better than stock :/

[zombiewolf513]

most people dont have dyes laying around as theyre expensive, and I wouldnt want to leave the die on the bolt while grinding. its just as easy to chase the threads after the bolts been cut.

with a die you always want to use oil but if your cutting the bolt with a power tool then ur have a chance of igniting the oil...so better to use oil and a die after the cutting process...

anyway glad you got the bolt done and enjoy those brakes they make a world of difference

Tap and die sets are common. And if he doesnt have one then who cares?

Unless the bolt were corroded as fuck, you probably wouldnt even need oil to begin with.

Putting the die on first shouldnt remove much if any material, and the point of the die going on first is to get rid of the chance of mashing or crossthreading the bolt by attempting to start the threading tool on the freshly hacked up end.

[russianphil18]

oil isnt for the bolt....oil is for the die. it protects it and lengthens the life of it. my point is that a steel nut is cheaper than a die and will chase the threads perfectly.

[Sileighty_85]

its a good thing the mount bolts thread in to a steel insert on the caliper....

[Koukiii]

its a good thing the mount bolts thread in to a steel insert on the caliper....

Only reason I did it like that. Cut steel bolt vs aluminum threads would be a nono

[zombiewolf513]

oil isnt for the bolt....oil is for the die. it protects it and lengthens the life of it. my point is that a steel nut is cheaper than a die and will chase the threads perfectly.

If youre threading a blank rod then oil yes, chasing two threads not as much. A steel nut might work too, its a matter of using what youve got and creatively solving the problem.