so I went to replace my front brake pads, no problem right? All went well...the pistons compressed back with out difficulty and pads swapped out in little time....but wait....there is more.......no compression at the lever or movement at the pistons....
no big deal, right? I removed the caliper and the new brake pads....pulled the pistons and found sand? in the piston cups....
(http://i1250.photobucket.com/albums/hh528/Derek_Grochowski/IMG_20120528_153314.jpg)
new seals, pistons and about 8 ounces of fluid/bleeding later....I still do not have a firm lever.....
Does anyone have any ideas or suggestions?
I would have bought a new caliper off of ebay (adidas and I have done this with success) as you can get a newer caliper with pretty fresh pads to boot. Now that it's off and your troubleshooting, pull the brake line from the caliper and see if you are getting fluid moving at all. It could be that your master cylinder has a problem. If worst comes to worst, pick up a hand pump and hook it to your bleeder to clear the lines and suck out air.
thanks for the input...after a thorough inspection of the brake system i found that the brake line is cracked and leaking. it cracked at the upper bracket where it attaches to the fork assembly....Replacement on the way....
after much summer distraction....I put the new break line on and while i was at it, i replaced the piston cup set on the master.....STILL SOFT BREAKS......no air in the line after bleeding 2 pints through the system....
recap:
new pads
new caliper seals and pistons
new line & banjo washers
new master piston cup set
DOT 3/4 break fluid
I have grease around the bleeder threads and i am using clear line to see air expelled from the bleeder valve.
Tomorrow, I will purchase speed bleeders, but I am doubtful they will help as I am not getting any air as it is...
any suggestions
Get a hand held pressure pump from harbor freight that you can stick on the bleeder, pump it up, then crack it open. I'm betting there is an air bubble blocking an open channel.
Sometimes air can get trapped in behind the pistons when they are mounted on the bike. maybe if you take the caliper off and fill it with brake fluid thru the brake hose bolt with it pointing upwards and bolt the hose back on it would get rid of the bubble? that's what happened with my street magic anyways.
I haven't actually had the brakes off my gs to see what they are like.
Like he said above, try taking the caliper off the bike and maybe try tapping it with the handle of a screwdriver while turning it upside down.......I have had stubborn air bubbles in wierd places before that were resolved by doing this.......Can't hurt to try it.
Quote from: Dizzledan on June 21, 2012, 07:03:31 PM
Get a hand held pressure pump from harbor freight that you can stick on the bleeder, pump it up, then crack it open. I'm betting there is an air bubble blocking an open channel.
I am not familiar with this method, can you elaborate?
Quote from: daski-emt on June 22, 2012, 06:01:35 AM
Quote from: Dizzledan on June 21, 2012, 07:03:31 PM
Get a hand held pressure pump from harbor freight that you can stick on the bleeder, pump it up, then crack it open. I'm betting there is an air bubble blocking an open channel.
I am not familiar with this method, can you elaborate?
Harbor Freight bleeder puts a vacuum on the bleeder, so when you crack it open, the fluid is literally sucked out, instead of pushed out by squeezing the lever.......the vacuum bleeder system is sometimes able to pull air bubbles out that are very stubborn.
So how mamy times should it take to "suck" the air out? Or to complete a bleeding?
Quote from: Dizzledan on June 21, 2012, 07:03:31 PM
Get a hand held pressure pump from harbor freight that you can stick on the bleeder, pump it up, then crack it open. I'm betting there is an air bubble blocking an open channel.
+1
You can also get them at many autoparts stores. Works wonders for this
The first time I put pressure on a new stainless steel line that wouldn't bleed, the lever was stiff. I kept going for good measure, but really 1 is all you need if the line is all ready full.
I got one, and it 7 times pulling down to -25in/mer to get a good feel on the break lever, I would like it more stiff but it stops well as it is...am i trying to over achieve or could there be an issue?