kotetu

UPDATE: I've updated the bleeding section with links to 2 articles.

Hey guys! I finished my brake install in about 3 hours with a friend. Pretty good time, it was the first time I've done the full install. We did one side at a time, if you are competent, you may do one and have your friend do the other.

Here's a DIY, I suggest you verify EVERYTHING in my list BEFORE ATTEMPTING ANYTHING!!! I take no responsibility for you hurting or killing yourself or anyone else. As always, if you do this mod, you are responsible for the results. Please be safe!

If anyone notices that I have left anything out or made a mistake, please point it out immediately!!

Enjoy!

Aaron

Parts installed:
1995 Legend GS Sedan front calipers (including pad spring)
1995 Legend GS Sedan front caliper brackets (including pad retainers)
1995 Legend GS Sedan Brembo Blank rotors (28mm)
Goodridge Stainless steel braided front brake lines

Tools used:
10mm wrench
12mm socket
14mm socket
17mm socket
19mm socket
1/4 and 3/4 ratchet
rubber mallet
impact driver
2 pairs of plyers (for those hard to access places)
various extenders and adapters
6000 lbs jack
jack stands
heavy duty ZIP ties
clippers (for zip ties)
a couple of flat head screwdrivers
a few small blocks of wood (for clamping to the calipers during bleeding)
Plastic jar or pitcher (to catch brake fluid)
bag of rags (to keep it clean)

Install time:
3 hours, with friend.


Install procedure:
Preparations!
01) obtain all parts first!

02) make sure you have at least 2-3 hours of free time and a friend to help!

03) get a copy or printout of the appropriate pages of the Helms manual

04) gather all of the tools

05) Print out this DIY!!! =D :thumbup:

Break down!
06) loosen all 10 lugs on the front wheels

07) make sure parking break is up, car can be in or out of gear

08) jack up car (from the front) so the wheels are about 2-3 inches off of the ground

09) place jack stands behind front wheels, to support the jack and protect your life

10) double check all jacks and supports to make sure that everything is safe.

11) remove 10 lugs from front wheels, remove wheels (don't scratch your wheels!)
You will now see the rotor, single piston caliper, bracket, and behind these the dust shield, rubber brake line, and suspension.

12) loosen and remove caliper bolts (2 behind the rotor)

13) zip tie caliper up to one of the supports for the suspension (not the spring) - Make sure you get it out of the way of the rest of your work, you will get back to this later.

14) remove, and place in a safe location, your brake pads.

15) loosen and remove the bracket bolts (2 more behind the rotor)

16) remove the caliper bracket and put it in a box

17) Using the impact driver, carefully pound and remove the 2 screws holding the brake rotor onto the hub.

18) remove the old brake rotor

19) unbolt brakeline from brake caliper, taking care to use a rag to avoid spillage
19b - cut ziptie holding old brake caliper, be careful the fluid does not spill! (plug the hole)

20) place end of brake line into the jar you brought to catch the brake fluid -
let this drip here for a while, maybe 10 minutes.


Installation!
21) Install new Legend rotor taking care to align the screw holes. Don't use the impact driver to tighten the screws! wipe down rotor with a clean cloth.

22) Install legend caliper bracket

23) replace your brake pads in the bracket

24) mount the Legend caliper on the upper bolt only!

25) swing caliper upwards (to point the bleed bolt and nipple up

26) zip tie the caliper so it does not fall back down.

27) optional step Remove the rubber brake lines (2 bolts) and replace them with the Goodgridge (or other brand) Stainless steel lines,

28) Attach your brake lines to the Legend caliper, using the 2 washers from the old caliper.

At this point you should double check all of your work, make sure everything is snug, not tight, (though the brake line fittings should be tight). If you are doing one side at a time, now is the appropriate time to do the other side. You are now ready to bleed the brakes! congrats!

Bleeding!

For bleeding, make sure you bleed the ENTIRE system, front and back. I'm including two links to bleeding articles, so you have some background. Remember that you'll need to angle the calipers up.

29) Take those small blocks of wood and carefully wedge them into the calipers. you may need more than one block. I used 3, and zip tied them in place. Try to fill nearly the entire volume of the caliper. You don't want those pistons popping out!

30-32)Article 1 Article 2

33) Repeat as necessary!

34) remove the wood blocks from the calipers, and gently slide the calipers down over the pads. (This may be a little difficult to do, but if you filled most of the caliper with the wood block, it won't be too bad.)

35) Bolt the lower caliper bolt to the bracket, and tighten all bolts in the brake system that need tightening.
35a) Before mounting wheels, double check ALL of the brake bolts and screws! There are 2 screws in the rotor, 2 bolts on the caliper, 2 bolts on the bracket, and 1 bolt on the brake line.

36) mount your two front wheels

37) test the car in a parking lot. test it a LOT. at slow speeds. Don't exceed 15 miles per hour. Remove the wheels and triple check the brake bolts!

If your car performed well, take it up to traffic speeds of 25-35 miles per hour and try some gradual stops. If you have done everything right, the braking should feel better than it did before you began. Run the car for a day or two, TAKING IT EASY!!!, and then you may want to bleed the brakes again, just to be safe.

You are DONE!! Congradulations and enjoy your new twin piston braking system!!!

If you have problems with the brakes, if they feel loose or unresponsive, then you still have air in the system. Go back to step 30, and bleed them again. Remember that while you are bleeding you need to build up brake pressure with the brake bleed bolt TIGHT. Once most of the air is out of the system, it will start to feel quite good!

Good luck guys! Remember to take is slow and cautious, and be safe! Your brakes are your life, be patient with the install and it will work out.


One of these days I WILL get pics!

MugenPoweredLude

i was thinking about doing this...just could never find a write up..now i have one....just dont forget the pics

good write up!

FAQ!!!

__________________
-Anthony- PSN/Xbox Live GT: Evoking1230
2005 EVO VIII-SOLD/R.I.P.
2000 Honda Prelude SH - Gone But Not Forgotten

blk97ludeSH

nice! lol you should have called me over! .. anyways.. i need to see it somtime..

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Bryan

natcc99

This is great!!!
Everyone is doing really fantastic write-ups!!
i love this site!

thanks!...very well done.
you didn't include any pictures, but from reading your instructions...you almost don't need any pictures!
(plus, it also helps that I have changed my brakes before)

this is definiately a FAQ.

when you get a chance, add some pictures to complete the write-up.


so, how does the car feel?!!?!
It sounds like you only did the front....any problem with brake balance?

are the brake pads the same size as the preludes or bigger?

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natcc99 photo album

kotetu

Yah next time I will give you a buzz.

I had a couple of problems this morning, a couple of shims came loose and I am gonna have to ditch them.

I lost a bracket bolt that I must not have tightened enough. Gonna get a new one for $0.50 from honda

The SS brake lines were pinched because the lines attach upside down on the caliper.
Basically I can either get longer SS brake lines, or rotate the calipers L to R, R to L. I am a bit worried about uneven pad wear, so I am gonna check the pads every couple of weeks.

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kotetu

Pictures will be added in a couple of days. Gonna take the wheels off again and take pics of the relevant areas.

The car felt really good yesterday. I posted some problems that appeared today. EVEN with the problems I mentioned, the brakes squeeze quite well, and I stop very quickly. Overall the feeling is much better.

Slowing from around 85 to 55 in a short distance (damn freeways) felt completely stable, at least as good as stock, and this has all of the problems mentioned below! I'm very impressed.

As for brake balance, I couldn't really say. I haven't tried cornering anywhere yet, and in straight lines there isn't much of a chance of locking up the rear brakes.

I reused my pads from the 5th gen prelude calipers. They fit perfectly. I do recommend getting NEW pads though, as my shims are falling off.

71dsp

Goodridge lines will fit, you just can't use the guides cast into the Legend's caliper body. I had Legend calipers on my 5Gen for a few months before I sold them. Mounting them upside down is the correct procedure, as the differential bore requires this. Don't be tempted to turn them around the other way! Not only will you have bad pad wear (very tapered), you'll greatly decrease the efficiency of the brakes.

Just play around with the mounting angle of the brake lines. You should be able to find a spot that works. I did, and I had no problems whatsoever. You are using 5Gen Prelude lines, right?

natcc99

sounds cool...glad everything is work out well.
you just have to fix a few minor details and you're all set.

have you seen the guy who put NSX front calipers on his 4th gen?!?!
I'll see if I can find it and post it up.


upgrading just the front brakes bother me just a little.
we have very heavy cars and it understeers easily especially how I have the Base S model with no ATTS.
My fear is upgrading the front brakes will only put more weight on the front and might be more likely to loose traction.

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natcc99 photo album

natcc99

here's the NSX caliper installation that I mentioned

http://www.superhonda.com/forum/show...hreadid=143969

$1400 a pair

http://www.cardomain.com/id/boostlee

kotetu

Thanks, I'll give that a try. That would be a good time to retake some pics too!

japnoyboi

Wow..nice write up. How come you did this? Are the legend calipers supposed to be better?

MugenPoweredLude

anything with dual pistons are better than stock

__________________
-Anthony- PSN/Xbox Live GT: Evoking1230
2005 EVO VIII-SOLD/R.I.P.
2000 Honda Prelude SH - Gone But Not Forgotten

MC_HondaRacing

What's the reason for changing to the Legend rotors? Are they larger, thicker, anything else?

kotetu

They are 28mm vs 23mm on the stock prelude rotors. They cool more efficiently and have a higher thermal capacity as well.

Also, using the legend rotor, bracket, and caliper, I don't have to use some kind of shim to keep the pads from falling out of the caliper.

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kotetu

Hey I found some Brembo documentation for why the smaller piston is the leading piston:
"The Brembo front calliper is a four-piston fixed calliper design with twin pistons on each side of the calliper, each pair dedicated to a pad. This advanced design features a smaller 40mm piston diameter at the front of the calliper to reduce the force on the leading edge of the brake pad. A 44mm piston in the rear of the calliper then exerts extra force on the pad to compensate for the tendency of the pad’s leading edge to bite into the rotor. This radically improves brake life and performance. "

*editing out the junk*

The brake line carries a certain pressure in the line itself. When that pressure is applied to the pistons, it is exactly the same inside the piston reservoir. But when you apply the same amount of PSI to different sized pistons, you get different *force*, hence the smaller piston *applies less force to the pad* because of it's smaller surface area.

Does this make sense? *now the brembo quote makes perfect sense to me*

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kotetu

This diagram I drew brings to mind several questions:

Which is the "front" of the caliper?
which side is the "leading" edge?
should the small piston be at the front or rear of the caliper?

The "front" of the caliper is the same as the FRONT of the car, but the "leading" edge of the caliper is the side towards the REAR of the car.

This means to reduce pad wear, the trailing piston must exert more pressure to reduce the 'biting' of the leading piston on the pad. The leading piston bites because of it's position at the edge of the 'incoming' rotor surface.

So, to increase the pressure on the the trailing piston, we should make it the *larger* piston.

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71dsp

No. The pressure on both pistons is exactly the same. They are in the same hydraulic "bath" and there is no restriction between the two pistons, so the pressure (measured in PSI) is exactly the same. So, since the smaller piston has a smaller surface area the force (measured in lbs) is smaller.

Your thinking is just a tad flawed. You're correct that the pressure in the brake lines will equal the pressure inside the caliper. However, the piston applies force to the brake pads. The force applied by the larger piston will be higher than the smaller piston because of the larger surface area. To measure the force, just multiply the pressure (in PSI) times the surface area (in square inches) of the piston. You will see that a higher surface area yields a higher force.

71dsp

I have never used "front" or "rear" when referring to the orientation of the caliper. Usually one refers to the leading edge of the pad and whether or not the caliper is leading or trailing. Also, you can extend the idea of leading edge to the caliper itself.

A leading caliper is a caliper that is mounted in front of the axle. A trailing caliper is a caliper that is mounted behind the axle. So, calipers are usually referred to as RHT, RHL, LHT, LHL (i.e. right hand trailing, right hand leading, left hand trailing, left hand leading).

In your diagram, both calipers are leading.

In my mind, I would say the leading "edge" of the caliper would be the "front" of the caliper, which is just opposite of what you're thinking, which can cause much confusion!

The leading edge of a brake pad is the edge that is in contact first with the rotor, as the rotor spins in the forward direction. In your diagram, the yellow piston is closer to the leading edge on the left wheel, and the blue piston is closer to the leading edge on the right wheel.

The smaller piston should "lead" the larger piston, i.e. the smaller piston should be closer to the leading edge than the larger piston.

Using your orientation of "front" and "rear", this makes sense, but be very careful when talking about "front" or "rear". I would keep things in terms of trailing and leading pistons (edges, or whatever). The reason why I say that is if you made the calipers trailing, the "front" of the calipers is now the "rear", and everything gets reversed.

Not correct for the reasons mentioned above.

kotetu

thanks for clearing that up! I knew something seemed weird. But then again it was 4AM

I kept taking PSI and square inches (area of pistons) and still got PSI instead of force in lbs!

So the larger piston applies a higher force to the rotor.... which means it should be the trailing piston right? In that case, the diagram on the left should be correct?

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71dsp

Yes, the diagram on the left is correct.

One other thing to note, the total area of the pistons on the Legend caliper is slightly higher than the total area of the piston on the stock Prelude caliper (IIRC), so that will shift your brake bias forward some.

Take a look at the Feb. 2001 Grassroots Motorsports magazine article "Pulp Friction" it describes brake operation (with formulas and such) very well. I found it to be an excellent article. While it doesn't necessarily address differential bore multi-piston calipers, it does explain how brakes work.