Q45/J30 brake how to install

[rustest86]

First, why do this over better pads and/or drilled/slotted rotors or 300zx brakes? 300zx brakes will not clear the stock wheels so unless new wheels are also in your budget those are out of the question.

Here's the cost list and tool list.

TOOLS:jack and jack stands1/2" ratchat13/16 socket19mm socket17mm socket14mm socket12mm socket10mm wrench4" angle grinder

COST:$44 used Q45 calipers, pads, and rotors ( i used a digital caliper and measured the rotors and pad so i knew i was getting good ones.)$0.00 machine work on rotors ( they owed me a favor )$56 new rear rotors, pads, and brake fluid$59 new passenger side rear caliper

TOLTAL:$159 for big brake upgrade and new rears for me

of course costs will vary with your area junkyards or if you use new calipers, rotors, and pads. and machine work.

Side by side comparisons of stock vs Q45:

as you can see there are 2 pistons vs the stock 1, the pads have slightly more contact area, and the rotors are thicker. this all translates into more clamping force along with more contact area which also transfers heat better to the rotor and having thicker rotors means more thermal capacity to withstand brake fad and boiling the fluid.

before you can even start the install, the rotors, OEM or aftermarket, need to be milled down 8mm off of the OUTSIDE diameter. this is done so that the rotor clears the caliper and caliper bracket.

to start installing the brakes, first start by lifting the car up and supporting it. next you need to "load" the suspension by jacking up the lower control arm untill the car just starts to lift off of you supports. next remove all the old brake hardware. i left the caliper connected so to not loose any fluid and prevent a mess. when you get everything tore down you should end up with this, now there are 2 options here you can do like me and remove the dust shield completely, or try trimming to clear everything. the only bad thing about trimming is the rotor sit sooo close that there is the posibility of it rubbing.

next you will need a grinder and grind on the lower control arm.

before grinding:

after grinding:

now to the people that question structual integrity about grinding on the control arm, you only need to take off a maximum of 1/16" of material. just enough to clear the rotor. this is also the reason of "LOADING" the suspension so that the control arm is at its closest to the rotor. you will need to grind and check often from full lock to full lock for proper clearances.

after this is done the caliper bracket can be bolted on, use the maxima bolts NOT the Q45/J30 as they are longer and will rub the rotor.

Next the inside pad can be installed, but the outside pad needs to be modified to clear the hub. your pad should look like this: you need to grind the lower part with the circle opening to the contor of the pad material. you do not need to grind ANY pad material, just the steel backing. and youll want to end up with this: now bolt the caliper on and bleed the system then move to the other side. i the end it sould look like this:

when i did this i also did new rear pads and rotors to complete the install, which was a good idea as i had 2 frozen slide pins, a bad caliper, and i was missing a clip that held the e-brake cable to the bracket.

DRIVING IMPRESSIONS:OMFG!!!!!!! this thing stops better than my 300zx brake equiped 240sx. my stopping distances dropped by at least 75ft under heavy braking. i also never felt any brake fad when i was bedding in the new brakes. there is more petal movement, but i like it as its easier to modulate them and keep them from locking them up. i also completely flushed the brake system and filled it with DOT-4 fluid. if you could get it i would use DOT 5.1 for a higher boiling point but DOT-4 is good for daily/spirited driving.

also to those who might "NEED" more, you could couple this with drilled/slotted rotors and hawk pads.

if you have any questions post em up and ill answer them.

[tigersharkdude]

MOD needs to sticky this. nice write up, wanna do this for me

[rustest86]

Thanks. I added a cost list and tool list.

[jltibbs]

Job well done!

You get a custom title for doing a write up, just let me know what you want and we'll get it taken care of!

***EDIT***

I added this to the how to's, which is in the sticky's, and I added your cost/tool info to the OP.

[rustest86]

thanks....... you can edit how ever you see fit. it took alittle longer than i expected because of the crappy weather and the family dutys durring the week.i also had to have the rotors milled twice as i went by what i had read and did 4mm the first time, it cleared the caliper bracket but not the caliper. but 8mm is perfect and theres still about 8-10mm between the pad and the outside edge of the rotor. i know i didnt list what year my car is, but its a 99 SE w/o ABS. i dont know if that matters to some people but anyway its listed now.

as far as custom title do "the silver bullet"thanks again

[Brandon8965]

does it matter the year on the q45 or are they all the same size?

[rustest86]

any year q45 or j30 they all had the same brakes

[Brandon8965]

very nice... thanks for posting my next project lol

[rustest86]

glad to help, deff worth it if you can get the parts cheap enough

[Brandon8965]

i have drilled and slotted brembo's on my max now with ebc red stuff.. do ya think i'll be able to find anything comparable?

[lino]

Nothing feels better than new brakes. Well done .

[rustest86]

i would think if you did this swap with bone stock parts you prob wouldnt gain anything but resistance to brake fad. now if you did this swap with some drill & sloted rotors and good pads........... that would have dash/steering wheel eater writen all over it

im gonna start looking into what we could use for the rears that would equal out the bias without modding the brake system itself, ya know bolt on stuff.

[Brandon8965]

nice.... meanwhile ima try and find these calipers and rotors for less than the 400 i keep seeing lol

[rustest86]

400???? what the hell man thats stupid high. your looking for q45/j30 calipers right? not 300zx.

you need to hit up some junkyards thats what i did....... if you have one around go to pull-a part their cheap as hell. i only paid $44 for the complete set.

[Brandon8965]

ha yea i was lookin at auto parts stores for new stuff just to see how ridiculous it could get and.. well i found it haha but yea there's a pull-a-part in my home town ima try and get a hold of..

question.. are the break boosters the same, like are the q45 calipers being used to their full potential by our boosters?

[rustest86]

see theres where you are confused.... the booster only does exactly what it says, it helps boost what ever amount of petal effort you put in, aka power brakes. what you are talking about would be the master cylinder. i can tell you that my 99 se has a 15/16 bore master cylinder. i think the q45 is bigger, how much so? i dont know, but if it is it wont be big enough to make that much difference. now say if you had installed 300zx calipers then i would say yes you need to upgrade the master cylinder also. and so far i havent been able to find a master cylinder that is setup the same as my 4 line non abs one that has a bigger bore.

my car does have slightly more petal movement than before but i still cant bottom it out without locking up the tires. and i find the extra modulation made it easier to control the braking and not lock the wheels up so its something i wouldnt worry about unless you add more than a couple brake pistons into the system.

also most abs cars do already have bigger master cylinders because of the extar crap in the system. and only use 2 lines which make it easier to just grab the q45 or j30 ones which are also 2 line if you have an abs maxima.

on my 240 when i did the 300zx calipers i ran the stock 7/8 master cylinder for awhile and it worked but it felt like mushy gm brakes. i currently have a 17/16 from a 300zx on it, now the petal is hard but, even harder to modulate. so im thinking ill get an abs 240sx 15/16 or an 300zx 1" master cylinder for it to fix it...... so you can get too big also.

[Brandon8965]

ha tis what i meant my bad but yea i don't hav abs.. and i have alot more petal movement than my previous volvo.. but then again my volvo's brakes were tha shizz

[Brandon8965]

o and how do you go about removing the brake dust shield?

[rustest86]

4" angle ginder...... lol made quick work of it......... there like $17 at harbor freight. i bought mine awhile back for a different project so i didnt list it in the cost.

[Brandon8965]

haha nice.... so there's no other way to take it off?

[rustest86]

you could use tin snips or a air die grinder, but at any rate it has to be cut.

[Brandon8965]

ha well these tin snips will be goin to use after all then

[rustest86]

have fun but you still need some sort of grinder to take care of the control arm and brake pad.

[Brandon8965]

ha well dang.. they're not too crazily expensive tho so it's all good

[Brandon8965]

ok i have all new calipers and rotors and such and everything's connected correctly, well as i know to, and it's been bled and everything and there is absolutely NO pressure happening at all... any suggestions?

[turbocat]

i had similar situation, when i was bleeding the brakes on my 98 max, i had the wife in the car pushing down the brake pedal, she pushed the pedal all the way to the floor, must have damaged the o-rings inside the master cylinder, I could not get the brakes to bleed, installed a new master cylinder, and put a block of wood under the brake pedal so wife couldn't depress pedal to far, then bleed brakes just fine, removed block of wood when done bleeding brakes, hope this will help.

[tater02]

great find man. How did you mill down 8mm off of the OUTSIDE diameter? What rear rotors and calipers did you use? Also, will this project work on a 2002 nissan maxima se; not sure if the caliper and bracket bolt patterns are the same for your max as they are on mine.

[tigersharkdude]

the A32-A33 both have 5x114.3 bolt pattern. Im not sure if this would work on a A33 because I dont know if the suspension components are different.

[VQ35er]

Try bolting the q45 caliper to the maxima caliper bracket. It bolts up and you don't have to shave the stock rotors.

[tater02]

VQ35er, what year maxima did you try the Q45 calipers on, and which stock rotor did you use that does not need shaved: maxima or Q45. Also, which is a better caliper Q45 or J30....J30 stopped production in 1997. Do you think the technology and performance of a 1997 J30 caliper are comparable to a 2003-06 Q45 caliper?