No Rear Brakes!

[grant1856]

I have no rear brakes. NO pressure at all. I checked the level of the fluid and it is OK. I tried bleeding them but the fuid did not come out at all. What is happening? The plunger is going up and the foot lever is going down. What should I check? Is there a common thing I should look for? The bike only has 20,000 miles and the front brakes are totally fine.

[HobbyMan]

Simple process: Clean and reassemble the rear MC. Did you put a new rebuild kit in it? Take the MC off and squeeze it by hand. Put your finger over the output hole to feel if there is any pressure at all. Did this happen suddenly or did you gradually loose breaking?

[mro]

only has 20,000 miles

and is 27 years old.
How long has the brake fluid been in there?
If after cleaning the MC brakes still not there, there are rebuild kits available.

If you find any "sludge" in the MC, most likely is in the caliper too.


mro

[grant1856]

Caliper question.

If it is in the caliper is that a problem? Can it be flushed or will I need to rebuild/replace?

[TopCatGr58]

Hey Grant,

IF there's lots of spooge and such in the MC, and in the brake lines, then there may also be a fair amount in the caliper! This Thread shows a front Special Caliper, but the construction is the same for the rear, can show you what you're looking at and that you can clean and rebuild it without necessarily needing a caliper rebuild kit. The O-rings are pretty tough, and usually just clean up easily and go right back in! Good Luck!
T.C.

[frogdink]

the exact same thing hapened to me all i had to do was take the rear caliper off and compress it with a clamp, with the bleeder screw open. but it all back together and then i was able to bleed them.

[grant1856]

Rear Brakes

I took it apart and cleaned it but now the piston won't go back in. Any ideas?

[frogdink]

make sure bleeder screw is all thw way open, cap is off of resivoir and you use a clamp...did you try all of that?

[grant1856]

Brakes

The resevior is completely off the bike and not connected to the caliper. I am going to replace the ring inside and te dust cover because they look to be beaten u a bit. That might be my problem.

[Hammerhead1st]

I have a standard, not sure if the brakes are the same...but on MY bike, I had to bleed the rear brake by making a CIRCUIT...a closed loop where the fluid continuously moves around in a circle.

I had to actually fill a bottle with fluid, run a hose off the bleeder into the bottle, leave the bleeder open , and allow the fluid to both push air out of the system, and also to suck fluid back into the caliper. Kind of a reverse bleeding technique. Once I got pressure on the pedal, I then bled the line out the normal way.

As for your spooge issue, TAKE YOUR TIME!! If you do it wrong you'll be in there again in 3 days. That just sucks. I used carb cleaner to get a lot of the crap out of my system, then flushed it all clean with 4 MC's full of brake fluid before refilling one final time. Of course...I'm on an unemployed person's budget, so I gotta use what I have on hand.

The important thing is to READ all of the info you can find in the tech tips about bleeding and rebuilding brakes. I've found the tech tips to be extremely helpful.

Hopefully, I havent wasted all this time typing...am hoping your brake system is similar to mine. Good luck!

[John]

Bleeding tip

I have found, especially on a Special, that the highest point in the front brake system is the banjo bolt that attaches the the brake hose to the M/C. I have also found that just cracking this joint loose and bleeding there first isn't always enough to get that last little bubble out of the banjo bolt. I usually reverse bleed, but even that method wasn't successful. My solution was, with the help of SWMBO, was first to remove the caliper from it's mount, and compress the caliper piston, ever so slightly, after removing the M/C from the bars and rotating it 90 begrees from horizontal. By doing this, the last of the trapped air is forced past the plunger and into the reservior, where it finally escapes the fluid. The difference was like having all new brake components again. My front brakes had never worked so well I guess, after experiencing the difference.
A trick for bleeding the rear is to remove the clamps attaching the brake hose to the swingarm, and the torque plate, and then remove the caliper from it's mount, and hold it up as high as the hose will allow. Now tap on the side of the hose to disloge any trapped air and let it rise to the caliper. Hold the caliper so that the bleeder screw is the highest point. Now crack the bleeder , and gently, slowly press the brake lever. Any trapped air should bleed out using this method.

[egsols]

Nothing has worked so far. I used the vaccuum pump, looked like all air was gone but first pull felt soft with next two or three pulls on lever nice and firm. The difference between the first pull and the following ones noticable.

I figure maybe the front right caliper was sucking air so I swapped in a single banjo at the splitter and rebled with just the left caliper. The lever became firm in no time. I then removed the left from the system, drained all fluid and retried with just the right side. Again I got a firm lever.

I then thought maybe the double banjo was the problem so I moved to the left caliper to avoid having it at the splitter. I then ran the right side line over the fender and rebled. Still getting a soft pull on the first try.

Any ideas?

[DiverRay]

You still have air SOMEPLACE in the system. Try putting it all back together but keep the splitter and MC off the bike. Put the MC on a 2X4, the splitter on a 4X4, and just tap lines starting at the MC. after a few minutes, put some pressure on the lever, and crack one of the bleeders. Do the same with the other, wait one hour and repeat.
That should allow all the air to migrate UP to the calipers, and give you a good feel on the lever.

[egsols]

Thanks Ray,

Not a bad idea, only problem is the splitter on the special is a bugger to get on and off. Maybe I'll pull the calipers and hang them as high as I can and leave the MC as low as I can.

At this time I'll try just about anything.

Ernie

[AlanB]

Hi egsols,

Problem may not be air...... If the pistons have been out, or even pushed all the way back, then the seals can take a grip of the pistons, and "flex" to allow the piston to squeeze the pad to the disc, then pull it back slightly when the pressure is released.

The symptoms are that the first pump is "soft", further pumps feel firm, but it returns to "soft" if left a moment......... Almost exactly the same as air in the system..........

Answer is to pump it up until "hard", and either clamp the lever in that position ( elastic cord? ratchet strap?) for a couple of hours, or just get your biggest buddy (I mean largest, not favourite!) to give it a "proper" squeeze. either method should put the piston and seal back towhere they should be.

The "pull-back" effect is always there; it is why disc brakes don't need return springs,while drum brakes do, but the effect can be exaggerated when pistons have moved a long way.

I avoid the problem by using a touch of proper brake grease on seals and pistons when building brakes.......everything just slides neatly into place.

AlanB