moto4 Posted January 30, 2012 Share Posted January 30, 2012 Rebuilt front and back brakes, added new stainless lines and blead brakes. Now I have no brakes. Started up the bike and rode it 20 feet to activate the abs and it did, but still no brakes what did I do wrong. 1997 R1100RT Link to comment
dirtrider Posted January 30, 2012 Share Posted January 30, 2012 Evening Moto4 Did you lift the fuel tank & bleed the fittings on the ABS controller? If you allowed the system to completely drain of fluid you probably have air trapped in the top of the ABS controller. You might also have to wedge the brake caliper pistons all the way in to decrease the air pockets behind the pistons in the calipers (or ride the bike a bit after the initial bleeding then re-bleed the calipers again) . Link to comment
OoPEZoO Posted January 30, 2012 Share Posted January 30, 2012 yup......what D.R. said. It takes a lot of work to bleed the brakes after you drain them completely. This might help. LINK Link to comment
moto4 Posted January 30, 2012 Author Share Posted January 30, 2012 Yes took tank off And bled the ABS I'm sure the system was completely empty when I started to put every thing back together. Link to comment
Selden Posted January 30, 2012 Share Posted January 30, 2012 Rebuilt front and back brakes, added new stainless lines and blead brakes. Now I have no brakes. Started up the bike and rode it 20 feet to activate the abs and it did, but still no brakes what did I do wrong. 1997 R1100RT HOW did you bleed the new brake lines? I replaced the brake lines on my 1999 RT about 10 days ago; using a cheap Harbor Freight vacuum brake bleeder, I sucked about 2 oz of fresh brake fluid through each brake caliper, and never touched the ABS reservoir. Based on feel, I am confident that there is absolutely no air in the system. I did have to clear an ABS fault (lights flashing alternately on power on), although I don't know that it was related to the new lines. After clearing the ABS fault, I got the familiar ka-chang sound of the ABS activating, a few feet after rolling forward. Link to comment
dirtrider Posted January 30, 2012 Share Posted January 30, 2012 Evening Moto4 Well you probably still have air trapped in the system yet. Probably some in the banjo fitting at the front master cylinder, some in the front pipe junction block, some behind the caliper pistons, some probably re-appeared in the ABS controller. You will more than likely need to move large amounts of fluid through the system to displaced the air as well a individually bleed at the front master cylinder & banjo fitting. Worst case you might have to reverse bleed or vacuum bleed ( but personally I don't like vacuum bleeding the early ABS systems) If you can get some brakes then ride the bike the air will eventually work it's way into the larger cavities. Link to comment
Selden Posted January 31, 2012 Share Posted January 31, 2012 Worst case you might have to reverse bleed or vacuum bleed ( but personally I don't like vacuum bleeding the early ABS systems). Inquisitive minds want to know why...? I'm not sure if 1999 qualifies as "early" or not. Link to comment
dirtrider Posted January 31, 2012 Share Posted January 31, 2012 Evening Selden The later 1150 I-ABS system was rated for partial vacuum bleeding, the earlier ABS-2 wasn't. BMW at one time recommended to not use vacuum to bleed the early ABS-2 systems so I took that to mean the controller could be damaged. I'm not sure if it will but the warning was enough for me to not do it. Link to comment
Selden Posted January 31, 2012 Share Posted January 31, 2012 As always, thanks for the clarification. Link to comment
AndyS Posted January 31, 2012 Share Posted January 31, 2012 Hi Moto4, it can take huge amounts of bleeding to get these things to clear trapped air. Drop a clean coin into the master cylinder such that it covers the fluid return port. This will stop the 'fountain' squirt when you release the lever. Make sure you remove the coin on completion. So with no appologies for repeatin some of what DR has said, get hold of a large container of new fluid and just keep cycling around each bleed point starting at the ABS unit, then RH calliper, then left hand calliper. Each time you bleed each outlet check that the fluid doesn't get low in the master cylinder. Can you see fluid coming out? Have you done anything else to the master cylinder? Sometimes the seal on the piston in the master cylinder can get a little damaged due to it travelling further into its bore than it has been used to, and in doing so can get damaged due to corrosion at part of the bore. This doesn't happen too often, but just bear it in mind. Link to comment
Selden Posted January 31, 2012 Share Posted January 31, 2012 Drop a clean coin into the master cylinder such that it covers the fluid return port. This will stop the 'fountain' squirt when you release the lever. Make sure you remove the coin on completion. Brilliant! I'm not going to stop removing plastic parts to a far distance, and covering everything up with newspaper and a large sheet of film, but geysering has been the number one frustration when changing the front brake fluid. Link to comment
dirtrider Posted January 31, 2012 Share Posted January 31, 2012 Morning Selden A coin works good as Andy mentioned. I have found a utility knife blade seems to work a bit better as they fit nicely into the contours of the master cylinder reservoir bottom. The utility knife blade is also magnetic so it is simple to remove afterward with a small pocket magnet. With a nonmagnetic coin you need to use a needle nose pliers or dig around with a screwdriver blade to remove. Link to comment
jjg3 Posted January 31, 2012 Share Posted January 31, 2012 I have found a utility knife blade seems to work a bit better as they fit nicely into the contours of the master cylinder reservoir bottom. The utility knife blade is also magnetic so it is simple to remove afterward with a small pocket magnet. Genius! Link to comment
dan cata Posted January 31, 2012 Share Posted January 31, 2012 Drop a clean coin into the master cylinder such that it covers the fluid return port. This will stop the 'fountain' squirt when you release the lever. Make sure you remove the coin on completion. Brilliant! I'm not going to stop removing plastic parts to a far distance, and covering everything up with newspaper and a large sheet of film, but geysering has been the number one frustration when changing the front brake fluid. There was a thread on this some time ago, someone asked what's with the coin inside, he found it while trying to change the fluid As I remember, the previous owner left the coin in there I have seen a GoldWing, made in 85', it had a part that does the con job inside the fluid reservoir. I was impressed with such a technology, afteral, it was made in 1985... Dan. Link to comment
Galactic Greyhound Posted January 31, 2012 Share Posted January 31, 2012 Hi Moto4, it can take huge amounts of bleeding to get these things to clear trapped air. Drop a clean coin into the master cylinder such that it covers the fluid return port. This will stop the 'fountain' squirt when you release the lever. Make sure you remove the coin on completion. So with no appologies for repeatin some of what DR has said, get hold of a large container of new fluid and just keep cycling around each bleed point starting at the ABS unit, then RH calliper, then left hand calliper. Each time you bleed each outlet check that the fluid doesn't get low in the master cylinder. Can you see fluid coming out? Have you done anything else to the master cylinder? Sometimes the seal on the piston in the master cylinder can get a little damaged due to it travelling further into its bore than it has been used to, and in doing so can get damaged due to corrosion at part of the bore. This doesn't happen too often, but just bear it in mind. Before you drop the coin in, are you seeing the 'Fountain squirt' from the master cylinder return port? If not, the tiny return port may be blocked making it impossible to bleed the brakes. The return port is the very tiny hole (approx 0.5mm dia) to the rear of the inlet port at the bottom of the reservoir - use a guitar string or very fine needle to clear it. See this link for info on the m/c return port: http://laudeman.com/bmw_r850r/front_master_cylinder.html If you will be bleeding vast quantities of fluid to try and prime a system, you can connect a long plastic tube from the bleed nipple back into the reservoir to save keep topping it up which should help prime a lot quicker. Once primed, leave overnight for any micro bubbles to settle out and then bleed normally. If there is still pressure but too much lever travel, zip-tieing the lever in the fully operated position and leaving overnight sometimes helps in clearing trapped air bubbles. Link to comment
philbytx Posted January 31, 2012 Share Posted January 31, 2012 Suffering from CRS and all that, I just cover my master cylinder with a lint-free rag..... Link to comment
racer7 Posted February 1, 2012 Share Posted February 1, 2012 The original mistake here was letting the system "go dry" for simply doing a caliper rebuild and replacing lines. A better idea would have been to plug the disconnected lines to prevent air from needlessly getting into the entire system. Try it the next time you do a major entry into a brake system and see for yourself how much effort it can save. (Many ABS systems on cars and bikes have nasty little places that tend to trap air and sometimes bleeding them fully requires ignoring the factory manual and cracking fittings in the right spot to get the air out- but that's a bit different subject. Life is much simpler if you just keep air from getting there in the first place) Rubber plugs/nipples for this use are readily available at parts stores- many look like the rubber top of an eye dropper- but you can use whatever will stop fluid flow. Link to comment
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