vvhy cant i bleed my brakes....
#1
#2
its not gonna be a stead stream coming out. also your sequence is a tad off to me.
here's what i do:
-make sure reservoir is topped off and leave cap off
-squeeze brake lever with one hand and crack bleeder open for one caliper
-when the lever goes does because the pressure is beng relieved make sure to be ready to snug the bleeder back down in time as soon as it the lever bottoms out.
- repeat that process a couple times for each side and you should be good and also more importantly, air bubble free.
here's what i do:
-make sure reservoir is topped off and leave cap off
-squeeze brake lever with one hand and crack bleeder open for one caliper
-when the lever goes does because the pressure is beng relieved make sure to be ready to snug the bleeder back down in time as soon as it the lever bottoms out.
- repeat that process a couple times for each side and you should be good and also more importantly, air bubble free.
#3
That's most likely because you allowed air to get back into the system, or you just have a lot of air in the system. When bleeding brakes, you must ensure the brake is compressed the entire time the bleeder screw is opened, or you will be sucking in air. Also make sure the master cylinder is topped off the whole time, though it will take several pumps to really drop it below the threshold, just be careful.
I use two 40lbs weights for my truck to keep the pedal down after I compressed the brake system, then I move to open the screw and close it quickly. The weight from the weights, will compress the pedal all the way when I release the bleeder screw. For the bike, I'd say you'd want to get one of them super thick huge rubber bands, like the one for broccoli at the grocery store, pump up the brakes till about the point a grown man would start to cringe from squeezing, hand clamp it then strap that band on there. Make sure it is tight! You should experiment a couple times before messing with the screw. Next release the bleeder screw about 1/4 turn, then close it quickly. You should witness the brake level close i guess you'll call it, but it should not have moved out. If it did, wrap that band a couple more times. You only open this screw enough to let it spit, then immediately close it. Rinse, and repeat until you do have a good spurt out. Should be just a quick spit, no stream like a good money shot from your favorite porno.
You may find some aquarium tubing to really help out, or you can buy a one man bleeder kit from your favorite parts store. It would have a hose to connect to the bleeder screw, and a bottle to put the tube into. Fill the bottle part way with clean brake fluid and put the tube into the bottle so the bottom of the tube is below the brake fluid. Next keep the bottle above the brake bleeder screw, you can figure this out, and do the same as above. This will give you a visual reference so you can watch for the ejecting fluid checking to see when bubbles stop flowing. Once done, move to the next brake. Always start with the brake furthest from the master cylinder, which my guess would be the rear, but that all depends on the setup of the master cylinder, slave cylinder if present, and the run of the lines. Most service manuals will give the proper bleeding procedure.
Apologies for continuing a tech issue in the wrong forum, but the answers back are more of a how to anyways... Don't crucify me please unless I'm gonna get a t-shirt
I use two 40lbs weights for my truck to keep the pedal down after I compressed the brake system, then I move to open the screw and close it quickly. The weight from the weights, will compress the pedal all the way when I release the bleeder screw. For the bike, I'd say you'd want to get one of them super thick huge rubber bands, like the one for broccoli at the grocery store, pump up the brakes till about the point a grown man would start to cringe from squeezing, hand clamp it then strap that band on there. Make sure it is tight! You should experiment a couple times before messing with the screw. Next release the bleeder screw about 1/4 turn, then close it quickly. You should witness the brake level close i guess you'll call it, but it should not have moved out. If it did, wrap that band a couple more times. You only open this screw enough to let it spit, then immediately close it. Rinse, and repeat until you do have a good spurt out. Should be just a quick spit, no stream like a good money shot from your favorite porno.
You may find some aquarium tubing to really help out, or you can buy a one man bleeder kit from your favorite parts store. It would have a hose to connect to the bleeder screw, and a bottle to put the tube into. Fill the bottle part way with clean brake fluid and put the tube into the bottle so the bottom of the tube is below the brake fluid. Next keep the bottle above the brake bleeder screw, you can figure this out, and do the same as above. This will give you a visual reference so you can watch for the ejecting fluid checking to see when bubbles stop flowing. Once done, move to the next brake. Always start with the brake furthest from the master cylinder, which my guess would be the rear, but that all depends on the setup of the master cylinder, slave cylinder if present, and the run of the lines. Most service manuals will give the proper bleeding procedure.
Apologies for continuing a tech issue in the wrong forum, but the answers back are more of a how to anyways... Don't crucify me please unless I'm gonna get a t-shirt
Last edited by entity-unknown; 04-10-2009 at 07:21 PM.
#4
1. Open reservoir.
2. Attach closed end wrench to bleeder screw.
3. Attach tubing to the nipple (lol) and the tube end into partially filled jar.
4. Loosen the bleeder screw & pump the brake.
5. When the reservoir level nears the bottom, close bleeder screw & fill reservoir.
6. Repeat steps 4 & 5 until brake fluid changes color.
7. Once you're satisfied with that particular caliper, pump the brake once last time and hold it down while simultaneously tightening the bleeder screw. Proceed to the next one.
8. Once you’re done with either the front or back, fill reservoir to specified level and secure the cover.
9. Check brake system prior to operation of the bike.
10. Marvel in glory of your mechanical accomplishment and bask to the fact that you saved some money.
2. Attach closed end wrench to bleeder screw.
3. Attach tubing to the nipple (lol) and the tube end into partially filled jar.
4. Loosen the bleeder screw & pump the brake.
5. When the reservoir level nears the bottom, close bleeder screw & fill reservoir.
6. Repeat steps 4 & 5 until brake fluid changes color.
7. Once you're satisfied with that particular caliper, pump the brake once last time and hold it down while simultaneously tightening the bleeder screw. Proceed to the next one.
8. Once you’re done with either the front or back, fill reservoir to specified level and secure the cover.
9. Check brake system prior to operation of the bike.
10. Marvel in glory of your mechanical accomplishment and bask to the fact that you saved some money.
#5
Hmmm your making me think that i bled mine wrong incognito
Here's what I did
Took cap off and topped off fluid
Pumped brake lever and held brake lever in
Loosen bleeder screw to let air/fluid out keeping brake lever held in
Tighten bleeder screw with brake lever still in
Once bleeder screw is tight, release brake lever
Repeated
Is that the wrong way to do it?
Here's what I did
Took cap off and topped off fluid
Pumped brake lever and held brake lever in
Loosen bleeder screw to let air/fluid out keeping brake lever held in
Tighten bleeder screw with brake lever still in
Once bleeder screw is tight, release brake lever
Repeated
Is that the wrong way to do it?
#6
Sounds right. If you take your system apart and put it back together (with new crush washers) you will have allot of air because your lines are empty. If that is the case, put the banjo bolts to just over finger tight and do not torque them to spec. Bleed fluid from the banjo bolt at the lever and each caliper, smacking the lines and calipers with a screwdriver or something to stir up the bubbles. Once bubbles stop coming out of the banjo bolts torque them down, then move onto the bleeder nipples.
I switched to a radial MC and if the MC is empty of fluid it wont punp. You have to get it working with fluid in it then you will have feel in the lever.
I switched to a radial MC and if the MC is empty of fluid it wont punp. You have to get it working with fluid in it then you will have feel in the lever.
#7
Is that the wrong way to do it?
#8
That's intriguing... "The book" has always said to hold the pedal in... I wouldn't be surprised of operation since these things are designed to work no matter what excluding a major leak.
But looking at the system in at least my truck you have the master cylinder which has a nice size spring type piston inside which has two pistons connected by a long shaft. One for front, one for rear. In between the separation inside the tube which makes up the body of the master cylinder, there are two port holes out the side which connects to the front and rear brake lines. These holes are position where they'd sit in the end of travel, but still be in the beginning of each section of the piston assembly.
The piston assembly moves forward and backwards by pressure applied through the power booster. The forward motion through presssure applied by the power booster compresses the piston assembly moving it forward which forces the fluid and makes something give, since fluid can't be compressed unlike air. What gives is the weakest point which in a working brake system is the caliper piston, which compresses the brake pad, and slows down your fun.
Now after it's applied it must return which it will via a large spring in the piston assembly. This is now going to draw back in your weakest link aka caliper cylinder so it doesn't keep the pad pressed to the rotor which will cause premature wear.
Now we open a bleeder screw, which is the new weakest link and pushes fluid out. Upon releasing the brake, it must return, and something must return with it. In this case it would be air coming back into the bleeder screw. One thing with bleeder screws is the ball. This will help in preventing suction of air back in the system, which may be your saving grace. The observation of fluid not going back into the tube is a good one and if that's what you're seeing then you should be ok. Perhaps these things are better than "The Book" describes, but I'll stick with my personal assurance since having a fault brake system at any speed sucks and normally there's only one way to figure that out....
But looking at the system in at least my truck you have the master cylinder which has a nice size spring type piston inside which has two pistons connected by a long shaft. One for front, one for rear. In between the separation inside the tube which makes up the body of the master cylinder, there are two port holes out the side which connects to the front and rear brake lines. These holes are position where they'd sit in the end of travel, but still be in the beginning of each section of the piston assembly.
The piston assembly moves forward and backwards by pressure applied through the power booster. The forward motion through presssure applied by the power booster compresses the piston assembly moving it forward which forces the fluid and makes something give, since fluid can't be compressed unlike air. What gives is the weakest point which in a working brake system is the caliper piston, which compresses the brake pad, and slows down your fun.
Now after it's applied it must return which it will via a large spring in the piston assembly. This is now going to draw back in your weakest link aka caliper cylinder so it doesn't keep the pad pressed to the rotor which will cause premature wear.
Now we open a bleeder screw, which is the new weakest link and pushes fluid out. Upon releasing the brake, it must return, and something must return with it. In this case it would be air coming back into the bleeder screw. One thing with bleeder screws is the ball. This will help in preventing suction of air back in the system, which may be your saving grace. The observation of fluid not going back into the tube is a good one and if that's what you're seeing then you should be ok. Perhaps these things are better than "The Book" describes, but I'll stick with my personal assurance since having a fault brake system at any speed sucks and normally there's only one way to figure that out....
Last edited by entity-unknown; 04-11-2009 at 03:11 PM.
#9
Yeah, I don't know about all that. A buddy of mine showed me how to do it like 20 years ago and I've always done it like that. Not that I'm disagreeing with you; obviously you know what you’re talking about. Guess I always felt that my method was one of the various ways brakes were done.
I've done brakes on a Cadillac, Chevy S10, Saturns(2), Subarus(2), and a Grand Caravan. Now had I observed the fluid/air being drawn back into the caliper, I'd use the open/close method, but from my experience, I've always noticed that the used brake fluid will drain from the nipple, and the brake line will draw from the reservoir, rather than suck it back in. BTW, I've always used clear nylon tubing with glass jars, cause I like to watch the little bubbles & stuff go through.
So what I do is, tell whoever is helping me to start pumping the brake (all the way out and to the floor). I'll open the bleeder and watch as the used fluid makes its way through the tube and into the jar. Once I feel the reservoir is running dry, I'll say, "press & hold", tighten the bleeder screw and refill the reservoir (and repeat).
You guys are starting to freak me out man ~ it's like my world is turning upside down, lol.
I've done brakes on a Cadillac, Chevy S10, Saturns(2), Subarus(2), and a Grand Caravan. Now had I observed the fluid/air being drawn back into the caliper, I'd use the open/close method, but from my experience, I've always noticed that the used brake fluid will drain from the nipple, and the brake line will draw from the reservoir, rather than suck it back in. BTW, I've always used clear nylon tubing with glass jars, cause I like to watch the little bubbles & stuff go through.
So what I do is, tell whoever is helping me to start pumping the brake (all the way out and to the floor). I'll open the bleeder and watch as the used fluid makes its way through the tube and into the jar. Once I feel the reservoir is running dry, I'll say, "press & hold", tighten the bleeder screw and refill the reservoir (and repeat).
You guys are starting to freak me out man ~ it's like my world is turning upside down, lol.
#10
So I asked around work and it appears like everyone uses the open/close method. I asked if anyone ever partially filled the waste container (the one the tube goes into) prior to bleeding, and no one did. So I'm wondering if that's the reason why the expelled fluid is not being siphoned back into the caliper (when I do it), because I do put brake fluid into that container beforehand.
...and entity-unknown, I didn't mean to blow-off your explanation there, it makes perfect sense; it's your basic hydraulic system setup. I've always thought that the master cylinder operated like a one-way valve. I’ve never replaced one, just calipers and a brake booster, so I don't know what they look like inside.
...and entity-unknown, I didn't mean to blow-off your explanation there, it makes perfect sense; it's your basic hydraulic system setup. I've always thought that the master cylinder operated like a one-way valve. I’ve never replaced one, just calipers and a brake booster, so I don't know what they look like inside.