| Author | Message | ||
     Mrsandman |
Need some pointers on this one. Yesterday I was trying to bleed my rear brake on my 99 X1, just after changing out the pads. Easy right! Well i've done it a million cars and used the same process. Un bolt caliper, twist off bleed screw, drain fluid by compressing cylinder, new brakes in bolt back on and start bleeding the system. Problem 1: Rear brake pedal felt like there was no fluid even in the system, which it did. No fluid came out with bleed valve open all while stomping on the rear pedal. nothing like you would imagine for a standard car. Problem 2: With my white flag waiving in the air, I call my older brother over who like me has tinkered with cars and bikes his whole life. He brought over a "HAND SQUEEZE VACUUM PUMP" for brakes. Ahhh this will work. So with the bleeder valve cracked open with teflon tape on the threads and master cylinder lid off we start sucking out a mixture of air and Dot 5. It looked promising. but it didn't work. Again the pedal has alot of play in it. Some how, some way we got it to a point where we can have a little rebound in the pedal but feel mostly like air. 4 hours go by and nothing. So I need some desperate help or ideas on this one folks, anybody please. Thanks. | ||
| Jramsey |
Reverse bleed with a syringe, 10 second job. After you do once it you'll never pump a lever again. | ||
| Desertguy |
Bleed master cyl. 1st, then caliper. Solved. | ||
| Jramsey |
Here's a pic of what I use, available at local farm store or veterinary clinic for about 3 bucks. Holds 60 cc.  When I said 10 seconds I wasn't bull shittin' either. | ||
| Azrael_cervale |
How exactly do you reverse bleed with the syringe? This sounds like genius. | ||
| Hybridmomentspass |
Mrs - may not be your problem, but i just had a problem bleeding my rear brake two weeks ago - check the bleeder valve. Apparently I'd overtightened mine while bleeding and it messed it up. Put a valve in from my dirtbike and it bled in no time and works perfectly. Then someone took a file to the 'bad' valve, we put it back in the dirtbike and it works great. Hope I helped at least a tad | ||
| Jramsey |
"How exactly do you reverse bleed with the syringe?" Teflon tape on the bleeder screw threads,open bleeder screw 1/4-1/3 turn. Slip hose from syringe over bleeder screw and inject fluid till bubbles quit appearing in reservoir and close the bleeder screw. Took me longer to type this than it takes to do it. | ||
| Natexlh1000 |
I tried to help my friend bleed his M2 rear brakes (his resovoir cap popped off somehow!) We bought one of those vacuum bleeders and wrestled with it for about an hour and a half with no luck. We finally gave up and brought it to the dealer. They fixed it for like 15 minutes of labor which made us both feel like tools. I guess the vacuum bleeders aren't the way to go? I never did find out what we were doing wrong. We pulled about a pint of fluid through the system and bubbles never stopped coming out! | ||
| Leftcoastal |
I have used my 'Mityvac' over and over with mediocre, if any, results everytime. I've got a couple syringes to try out next time. I'm thinking the vacuum sucks air through the bleeder screw threads, as I get the same results with constant air bubbles no matter how long you work at it. Maybe it's one of those head-slap things - put some teflon tape on the threads just like James said and it'll work like a charm, only with the vacuum tool instead of the syringe. | ||
| Lager |
The problem started when you drained the fluid from the caliper and the lines. No reason to do that when changing pads. next time, just push the caliper back in. replace the pads and pump the pedal till the pads seat against the rotor. Getting back to your procedure and why you couldnt get a firm pedal is because you introduced air into the system.Motor cycles , as compared to automobiles displace very little fluid during, even a full stroke of the cylinder. This means that during your bleeding procedure of ,press,release of the bleeder, might work on an automobile ? The little fluid the MC actually pushes,wont actually clear the lines of air. Air rises to the top of the brake line. The time it takes you to rest the pedal, the air bubble came back to where it was. Jramsey brought up a good idea. You will have to pressurize the system to purge all the air.You can do it two ways, from the caliper or the reservoir.His way is easiest. Next time, for anyone that is listening ? No need to dump fluid to change pads, just compress the piston back, pliers work well. Then if you want to replace fluid, then do the press and release method using the bleeder screw while filling the reservoir as you go. Hope all this helps. | ||
| Jramsey |
I Like the OP have always bleed brakes from the m/c down(several hundred if not thousand's race cars and motorcycles). I had heard of reverse bleeding in the past but didn't think much of it since I never had a problem bleeding brakes. Last month I mounted a set of tires on a '05 Sportster and the rear brake was $hit when done , spent 3+ hours trying to bleed in the normal fashion...........zip.. nada nothing, pumped my brains out no rear brake. Took the caliper apart first then the m/c, everything perfect tried to use Mity Vac. to no avail. Googled Sportster rear brake bleeding and everything said reverse bleed because the master is below the caliper and the hard line that the brake switch is located at the highest point in the system. I used the syringe method and it filled the system (completely dry) in the time it took me to squeeze the syringe half way. Rock hard pedal.....first time. | ||
| Lager |
Good point Jramsey. While the X1's master cylinder and the caliper are at about the same height, it still has that same high mounted brake light switch problem the Sports has. Good suggestion Jramsey !! | ||
| Chad22 |
hopefully you didnt do what i did. pusged the piston back without opening the bleeder and pinching the line, i toasted my rear mater doing that. | ||
| Buellized |
Hi. I've have friend with an S1 that we tried to bleed the rear brakes on for many hours, but didn't manage to build up any pressure at all! We tried traditional bleeding, syringe and even took of the caliper off and elevated it to avoid air getting trapped, but nothing helped!  And that is when he tried something completely different that worked instantly!  He filled the syringe and pushed the brake fluid down the little hole in the reservoir! He was out riding 10 minutes after he came up with the idea... | ||
| Kalali |
So was the line clogged or something or piston stuck? | ||
| Purpony |
i use this to bleed all by brakes- http://www.harborfreight.com/air-vacuum-pump-with- r134a-and-r12-connectors-96677.html the catch can inline between the caliper and vacuum pump i originally got from this kit- http://www.harborfreight.com/mityvac-vacuum-pump-3 9522.html BUT, i was at CarQuest the other day and noticed they sell just the catch can for a couple bucks. I just hook the vacuum pump up to my compressor and turn it on. Pulls the fluid right through. I can do an car or bike all by myself in mins. |
