bobsmith
9th December 2006, 10:39
I've just gone and cleaned my brake parts out and put some new grease on them a few days ago and went to bleed them. Now the rear brake was easy enough, but when I went to do the front one, I kept on pumping the brakes but they just wouldn't pressurise (read: it felt spongy and it didn't go away when the brake pads moved all the way to the and they were in the right position) no matter how much pumping and bleeding I did.
I wasted several hours doing this, did some search on google and here and found out that problem is most like air bubbles stuck just below the master cylinder.
Now all the posts suggested that I would need a pressure bleeder to force the brake fluid from the bottom to get the air out and should take it to the shop but of course being stubborn I couldn't do that. (besides the fact that I've got no money...)
So here's what I did and fixed my problem within 15 minutes (wish I thought of this earlier) If you're having trouble of no air bubbles coming out from the calipers (ie only brake fluid coming out suggesting that the calipers are bleed of air) but the brakes still feel spongy here is what you can do:
1. First bleed the brake as much as you can.
2. When you've bleed the brake so that the slave cylinders (the brake caliper) is full of brake fluid (you can tell by when you're bleeding that only brake fluid is coming out) get a G-clamp and start pushing the pistons back.
3. Hopefully that should force the brake fluid up the line to the master cylinder and should get that airbubble out. Becareful that you don't spray yourself with brake fluid as you do this (picture you croutching down pushing the pistons back then the air bubbles come out the top and you had too much brake fluid in the master cylinder and it goes all over the place... not fun)
4. Now pump the brake and let the pistons out a bit then press them back again and repeat this a few times until the pistons come out [insert a word that I can't think of here... (well?) ] with the pumping of the brake lever (before you start pushing the pistons back to bleed the line and the master cylinder you'll see that pumping of the lever doesn't push the pistons out as well as it should, well now it should push them out quite easily)
5. you're done, reassemble the brake caliper then bleed the brake as per normal.
Now I've written this with my limited knowledge of how the brake systems work and from my experience with the brake bleeding nightmare. Take into account that I've only bleed 4 brakes before if anyone can suggest a correction to these please let us know!
I wrote this because I wasted 6 hours and almost a whole bottle of brake fluid trying the bleed the front brakes, hopefully this should save some time for another person with similar problems.
I wasted several hours doing this, did some search on google and here and found out that problem is most like air bubbles stuck just below the master cylinder.
Now all the posts suggested that I would need a pressure bleeder to force the brake fluid from the bottom to get the air out and should take it to the shop but of course being stubborn I couldn't do that. (besides the fact that I've got no money...)
So here's what I did and fixed my problem within 15 minutes (wish I thought of this earlier) If you're having trouble of no air bubbles coming out from the calipers (ie only brake fluid coming out suggesting that the calipers are bleed of air) but the brakes still feel spongy here is what you can do:
1. First bleed the brake as much as you can.
2. When you've bleed the brake so that the slave cylinders (the brake caliper) is full of brake fluid (you can tell by when you're bleeding that only brake fluid is coming out) get a G-clamp and start pushing the pistons back.
3. Hopefully that should force the brake fluid up the line to the master cylinder and should get that airbubble out. Becareful that you don't spray yourself with brake fluid as you do this (picture you croutching down pushing the pistons back then the air bubbles come out the top and you had too much brake fluid in the master cylinder and it goes all over the place... not fun)
4. Now pump the brake and let the pistons out a bit then press them back again and repeat this a few times until the pistons come out [insert a word that I can't think of here... (well?) ] with the pumping of the brake lever (before you start pushing the pistons back to bleed the line and the master cylinder you'll see that pumping of the lever doesn't push the pistons out as well as it should, well now it should push them out quite easily)
5. you're done, reassemble the brake caliper then bleed the brake as per normal.
Now I've written this with my limited knowledge of how the brake systems work and from my experience with the brake bleeding nightmare. Take into account that I've only bleed 4 brakes before if anyone can suggest a correction to these please let us know!
I wrote this because I wasted 6 hours and almost a whole bottle of brake fluid trying the bleed the front brakes, hopefully this should save some time for another person with similar problems.