Inconsistent Squishy Brakes
- Thread starter nodakgus
- Start date
Gorecki
Member
I would think that it would be fairly hard but not entirely impossible. 'Contaminants' (brake dust, dirt, corrosion) working their way into the caliper between the piston and seal, sitting on the bleeder going into the system during a flush, heck even a little dirt falling into the system taking the cap off because of a speck of muds tucked away. I could see it happening.
HondaGalToo
Control Rider
The way I've heard of people doing it is to fill a syringe with brake fluid, get tubing and attach one end to the syringe and the other end on the caliper bleed nipple. Prime the tubing with brake fluid before attaching it to the caliper bleed nipple. Remove the reservior cap, and push fluid up by depressing the plunger on the syringe. Of course being careful not to push so much or so hard that you overflow the reservoir. Not possible with speed bleeders due to the check valve.
I guess the thought is to force bubbles up and out into the reservior. Never tried it myself.
Landshark
Control Rider
I agree. I also use the vertical hose method.
I think Joe did misinterpreted what I had posted. NEVER flush old dirty fluid backwards. If the fluid is clean and its and tiny air issue that often happens after new lines etc... I said let those tiny bubbles rise rather than trying to force them down. For me they become trapped in the master cylinder and are easily bleed from that bleeder.
Gee-sh pushing dirty fluid backward is like brushing your teeth with sand.
bigkaley
Control Rider
Alright, let me just start with the statement that this is MY routine and does not mean that it's "The Best" way, just what has worked for me.
First off, there have been 2 general types of brake service that I've done, one is basically cleaning calipers and replacing with NEW brake pads. The other involves some type of disassembly of the brake system and changing/ flushing of brake fluid.
Either way, the basic steps are the same. I don't use MityVac's or Speedbleeders, just the old fashioned "pump and bleed" method.
The following are the steps I take. I work on one side at a time leaving the other caliper attached to the bike. I usually start on the Left side first, mostly because if the bike has an OEM type "over the fender" piggyback line the steps would warrant starting on the left first. For Race Lines that both go directly to the master cylinder, I don't know that it would matter.
1-Loosen the brake pad pin bolts. If the caliper uses "R" type clips on the pad pins, you can just wait until step 4 to remove the "R" clips.
2-Loosen the brake caliper mounting bolts and remove the caliper from the rotor without pushing the brake pads apart and pushing the brake pistons back.
3-While holding the caliper with your hand, pump the brake lever to close the gap between the brake pads. This will expose an obvious line from where the brake dust/dirt has built up on the pistons. You don't have to close the pads completely, just until enough of each piston has been exposed.
4-Remove the brake pad pin bolts ( "R" clips), remove the brake pads, and remove the Anti-rattle spring plates if they're still in place
5-Now take your favorite toothbrush and grab something to clean the calipers/pistons with. I know this is another area where everyone has their own favorite cleaner, I just don't suggest using any common type brake/ contact cleaner. I use Suzuki Bike Wash (comes in a 32oz. Black spray bottle with Blue label) that I cut down 50/50 into another 32oz. bottle with water. Also grab another spray bottle of plain water. The Suzuki Bike Wash works really well and won't hurt anything if you get overspray on the bike. Wash/ clean the caliper, pistons, pad pins, Anti-rattle spring plates thoroughly and rinse with plain water. Use compressed air to blow them dry and hold them with a towel behind them to keep from blowing the water all over......unless you have a nosey person who keeps getting in the way and is driving you nuts, then don't use the towel....whoa, where'd that come from??
6-Now comes the slightly more difficult part, but not too tough. Pushing the pistons back in. I only use my fingers.....waiting for it.........YES I CAN FIT MY FINGERS IN THERE....
now back to the subject, if I'm changing/ flushing fluid, here's where I put a clear hose on the bleeder, crack it open, and when I'm pushing the pistons back in carefully, I'm pushing the dirty, old brake fluid out of the caliper through the bleeder into the container. After I get the pistons retracted fully, then close the bleeder. If I'm changing/ flushing fluid, I also use a large syringe to pull the old fluid out of the master cylinder reservoir and dispose of it. Then clean/ wipe out the reservoir and add some fresh NEW brake fluid.
7-Now install the NEW brake pads, cleaned brake pad pins, Anti-rattle spring plates (if used) and install the caliper onto the fork mount. Install the brake caliper mounting bolts only finger tight, and also DON'T pump the brake lever.
8-Now go to the other side and repeat.
9-After both sides are done, calipers are installed with finger tightened bolts and reservoir is at least 1/2 full of fresh fluid......DON'T PUMP THE LEVER YET.... use the wooden handle of a hammer to tap from each caliper up the lines to the master cylinder and the banjo bolts. Watch the reservoir for any bubbles.
10-Now pump the brake lever to get pressure. Also at this point, bleed/ flush each side with your favorite method until you have clean/ clear fluid.
11-When you're finished flushing/ bleeding don't fill the reservoir. Just so it isn't too low.
Now here's my last step- I go back to the left caliper, loosen and take off the caliper mounting bolts one last time, lift the caliper off the mount but keeping it on the rotor. Then gently twist the caliper both ways to use the rotor to push the pads all the way back and the pistons all the way retracted. Do it gently and make sure that just the lid without the diaphragm/ bladder is loosely on the reservoir while you're twisting the caliper and forcing the fluid back up. Hopefully here is where you're catching any bubbles. Now install/ torque the caliper/ mounting bolts. Go to the other caliper and do the same thing again. Then install/ torque. Tap all the lines and banjo bolts with the hammer handle again before pumping the lever. Watch the reservoir for any bubbles.
Pump the lever to get pressure. Don't let the reservoir get too low. Fill the reservoir no more than 2/3 full with fresh NEW brake fluid when installing NEW brake pads.
Again, this is just my system that has worked for me. If it helps, great.
First off, there have been 2 general types of brake service that I've done, one is basically cleaning calipers and replacing with NEW brake pads. The other involves some type of disassembly of the brake system and changing/ flushing of brake fluid.
Either way, the basic steps are the same. I don't use MityVac's or Speedbleeders, just the old fashioned "pump and bleed" method.
The following are the steps I take. I work on one side at a time leaving the other caliper attached to the bike. I usually start on the Left side first, mostly because if the bike has an OEM type "over the fender" piggyback line the steps would warrant starting on the left first. For Race Lines that both go directly to the master cylinder, I don't know that it would matter.
1-Loosen the brake pad pin bolts. If the caliper uses "R" type clips on the pad pins, you can just wait until step 4 to remove the "R" clips.
2-Loosen the brake caliper mounting bolts and remove the caliper from the rotor without pushing the brake pads apart and pushing the brake pistons back.
3-While holding the caliper with your hand, pump the brake lever to close the gap between the brake pads. This will expose an obvious line from where the brake dust/dirt has built up on the pistons. You don't have to close the pads completely, just until enough of each piston has been exposed.
4-Remove the brake pad pin bolts ( "R" clips), remove the brake pads, and remove the Anti-rattle spring plates if they're still in place
5-Now take your favorite toothbrush and grab something to clean the calipers/pistons with. I know this is another area where everyone has their own favorite cleaner, I just don't suggest using any common type brake/ contact cleaner. I use Suzuki Bike Wash (comes in a 32oz. Black spray bottle with Blue label) that I cut down 50/50 into another 32oz. bottle with water. Also grab another spray bottle of plain water. The Suzuki Bike Wash works really well and won't hurt anything if you get overspray on the bike. Wash/ clean the caliper, pistons, pad pins, Anti-rattle spring plates thoroughly and rinse with plain water. Use compressed air to blow them dry and hold them with a towel behind them to keep from blowing the water all over......unless you have a nosey person who keeps getting in the way and is driving you nuts, then don't use the towel....whoa, where'd that come from??
6-Now comes the slightly more difficult part, but not too tough. Pushing the pistons back in. I only use my fingers.....waiting for it.........YES I CAN FIT MY FINGERS IN THERE....
now back to the subject, if I'm changing/ flushing fluid, here's where I put a clear hose on the bleeder, crack it open, and when I'm pushing the pistons back in carefully, I'm pushing the dirty, old brake fluid out of the caliper through the bleeder into the container. After I get the pistons retracted fully, then close the bleeder. If I'm changing/ flushing fluid, I also use a large syringe to pull the old fluid out of the master cylinder reservoir and dispose of it. Then clean/ wipe out the reservoir and add some fresh NEW brake fluid.7-Now install the NEW brake pads, cleaned brake pad pins, Anti-rattle spring plates (if used) and install the caliper onto the fork mount. Install the brake caliper mounting bolts only finger tight, and also DON'T pump the brake lever.
8-Now go to the other side and repeat.
9-After both sides are done, calipers are installed with finger tightened bolts and reservoir is at least 1/2 full of fresh fluid......DON'T PUMP THE LEVER YET.... use the wooden handle of a hammer to tap from each caliper up the lines to the master cylinder and the banjo bolts. Watch the reservoir for any bubbles.
10-Now pump the brake lever to get pressure. Also at this point, bleed/ flush each side with your favorite method until you have clean/ clear fluid.
11-When you're finished flushing/ bleeding don't fill the reservoir. Just so it isn't too low.
Now here's my last step- I go back to the left caliper, loosen and take off the caliper mounting bolts one last time, lift the caliper off the mount but keeping it on the rotor. Then gently twist the caliper both ways to use the rotor to push the pads all the way back and the pistons all the way retracted. Do it gently and make sure that just the lid without the diaphragm/ bladder is loosely on the reservoir while you're twisting the caliper and forcing the fluid back up. Hopefully here is where you're catching any bubbles. Now install/ torque the caliper/ mounting bolts. Go to the other caliper and do the same thing again. Then install/ torque. Tap all the lines and banjo bolts with the hammer handle again before pumping the lever. Watch the reservoir for any bubbles.
Pump the lever to get pressure. Don't let the reservoir get too low. Fill the reservoir no more than 2/3 full with fresh NEW brake fluid when installing NEW brake pads.
Again, this is just my system that has worked for me. If it helps, great.
Matt
New Member
my favorite easy way to really check if a rotor is true is the following.
put the bike on a front stand (fork or stem doesn't matter)
look at the rotor, hold the tip of a small screw driver very lightly, but very steady against the rotor. use the fork / fender to stead your hand. I typically use a dial indicator w/ magentic base to get an actual measurement but common sense and the screwdriver work well.
spin the wheel. if the rotor moves away / towards the screw driver, it's bent. the other issue is it could be warped (dished, etc). you can only see that after taking it off and placing it on something flat.
my bet is still one is bent and the screwdriver trick will show you in about 10 seconds.
nodakgus
Member
Progress
Changed the brake fluid and ruled that out. I pulled the fender and calipers and spun the wheel fast several times and it appears to me that the entire wheel has a slight wobble. Last winter I did change out my tires while the bike was in the house. I am thinking I did not get the wheel correctly installed. Started to take off the wheel when the dinner bell rang so I will pick this up tomorrow morning. My gut instinct is that this has to be the problem. If not, I have a couple of ebay sellers bookmarked for a couple of used rotors. I don't have the time to ship the rotors out somewhere to get them straightened.
Changed the brake fluid and ruled that out. I pulled the fender and calipers and spun the wheel fast several times and it appears to me that the entire wheel has a slight wobble. Last winter I did change out my tires while the bike was in the house. I am thinking I did not get the wheel correctly installed. Started to take off the wheel when the dinner bell rang so I will pick this up tomorrow morning. My gut instinct is that this has to be the problem. If not, I have a couple of ebay sellers bookmarked for a couple of used rotors. I don't have the time to ship the rotors out somewhere to get them straightened.
HondaGalToo
Control Rider
Spacers in your wheel? Installed on the correct sides?