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View Full Version : BRAKES ARE SPOUNGY



motaboy
Mon Mar 26th, 2007, 08:04 AM
I RECENTELY DID A BRAKE JOB ON MY 05 ZX-10R, I SWAPPED OUT THE STOCK PADS FOR EBC HH, I USED MOTUL DOT4 RACE BRAKE FLUID AND THE BIKE HAS GALFER BRAIDED LINES FRONT AND REAR. AFTER BLEEDING THE BRAKES WITH TWO BOTTLES OF FLUID USING A VACCUM ASSIST, THE FLUID LOOK FREE OF AIR BUT WHEN I RIDE THERE IS STILL A LOT A PLAY IN THE LEVER AND PEDAL. I DID THE SAME THING ON MY 03 636 AND THE BRAKES ARE MUCH STRONGER AND THE FEEL IS MUCH BETTER. ANY IDEAS BEFORE I RE-BLEED THE ENTIRE SYSTEM.

THANKS,
MOTABOY

Bassil Duwaik
Mon Mar 26th, 2007, 08:15 AM
Take it easy on them the first 100mi. till you break them in

~Barn~
Mon Mar 26th, 2007, 08:27 AM
:wtf: Um... I don't think he's talking about bedding in the pads there Duwaik.

Anyway.... Something obviously isn't quite right if they're feeling that way. The last thing that kind of upgrade should display, is play in the lever, the spongy feel, etc. Just like with your 636, they should feel extra stout and have minimal lever travel.

I'm thinking the re-bleed idea might be your answer. G'luck with it.

Lurch
Mon Mar 26th, 2007, 08:31 AM
:imwithstupid:

I think a re-bleed is also in order. Don't use the vacuum and see if this gets you where you need.

Lurch

bluedogok
Mon Mar 26th, 2007, 08:49 AM
I have not had much luck using the Mity-Vac for bleeding, it's great for sucking the old fluid out of the system though. I always use the traditional method of the bleeder screws. If there is slight sponginess, one trick is to strap the front brake lever to the handlebar and leave it over night. That has helped some with the spongy Triumph brakes. If it is bad enough, use the bleeder screw method.

The_Jackel
Mon Mar 26th, 2007, 10:32 AM
If there is trapped air in the system a vacuum aka mighty vac will not get the air out most of the time. You have to use pressure to get the air out, the cheapest best way to do that is a speed bleeder. I like motion pro alot and there like 15bucks and its worth its weight in gold!! If not just get a buddy to help you and unscrew the bleeder a half turn to bleed.

The GECCO
Mon Mar 26th, 2007, 11:09 AM
The vacuum pumps aren't that great for a final bleed. Here's a trick that might help - remove both calipers from their mounts. Take the cap off of the reservoir. Push both brake pads to one side of the caliper and, using a screwdriver against the metal backing of the pad, slowly push ALL of the pistons all the way back into the caliper. Do NOT use any tool against the friction surface of the brake pad. Carefully watch the reservoir to make sure that it doesn't overflow. Use the mighty vac to suck some fluid out if necessary. Sometimes when you push one piston in, others will come back out instead of sending the fluid back into the reservoir, so make sure all of the pistons in both calipers end up all the way back in the calipers at the same time.

Once this is done re-install the calipers. Slowly pump the brake lever until the pads touch the rotors. Watch your reservoir level to make sure you don't run it dry and suck air into the system. You may have to repeat this whole process, but once usually gets it done.

The idea behind this is that any air that is in the calipers or lines gets flushed upwards towards the reservoir and then only fluid is replaced when the brakes are pumped back up. I do this just about everytime I change tires on the racebike (ie once per weekend) and it really helps keep things firmed up.