Help Bleeding the rear brake

[Kevrg]

Hey everyone. I'm new to the forum and I've been looking around a lot for an answer to this, and I apologize if I missed it and am making a redundant post. My question is, when bleeding the rear brake, is it best to start from the bleeder valve in the back by the brake, or the one that comes up in the front underneath the fairing? I have an 88 so my rear brakes aren't tied in with the front, but there is still a bleeder valve located up front, but as far as I can tell, it doesn't link to anything. Any help would be appreciated. Thanks!

[KIC]

Unless the Previous Owner (PO) disconnected your front brakes from the rear, they are connected. I bled my rear, then the valve in the fairing area, and then the back again. This was also because I wanted to clean out the brake fluid.

 

Welcome to the forum. Join so you get all the benefits. It is worth many times more than the $12.00.

[Venturous Randy]

Unless the bleeder under the front fairing is blocked off, it should connect to the left front caliper. If so, it will need bleeding also as part of bleeding the rear brake.

When bleeding, especially the one under the fairing, be very careful that you do not get ANY brake fluid on any of the plastic as it will ruin it.

Also, when you fill the rear brake reservoir, make sure that when you are done that it is not too full. If it is too full, as the brakes heat up, it will start dragging to the point that it will stop you. You should always keep an 8mm wrench on the bike, especially after brake work.

What I have found that really helps me on the rear brake bleeding is to get one of the plastic turkey basters and pull the bulb off and the tip of the tube will screw down into the reservoir. It won't leak and you can see how much fluid you have so you do not pump the reservoir dry.

It also helps to have someone help you on the front left caliper.

RandyA

[Kevrg]

Thank you guys for the input! I thought I had read somewhere that after 86 they stopped linking the front and rear brakes but I must have read wrong. I will give everything a try, and hopefully be riding with both brakes by the end of the day. So I don't need to bleed the front brakes at all if they are working properly?

[KIC]

There are two purposes for bleeding, one to get the air out..but the other is to get the old fluid that might have water ( condensation) in the system. So bleeding and adding new fluid as you bleed, cleans your system.

[Kevrg]

So I bled the rear brake, from the rear, then I bled it from the front bleeder in front of the fairing, now my rear brake is locking up instead of not working at all. Any tips?

[BlueSky]

So I bled the rear brake, from the rear, then I bled it from the front bleeder in front of the fairing, now my rear brake is locking up instead of not working at all. Any tips?

 

Is the left front brake caliper working correctly? If it is you may have to rebuild the rear caliper. Make sure the master cylinder is not too full as informed from a previous post.

[ricksbike]

I just bled the brakes on my 92 vr and factory manual says front----rear--bleeder by steering head also it says to remove front bolt on rear caliper and tip it up an inch and a half--I did all this and had no issues.

[Kevrg]

The front left caliper was dragging pretty bad for a little while, so I went back and bled from the bleeder valve below the fairing again and then it stopped. When I bleed the rear brake it will work fine for the first couple pumps, but as soon as I give it one real good one, as if I were to slam on the brakes, it completely locks up on me. Maybe I need to the full bleeding process and do both the front brakes too? Really hoping I don't need to replace/rebuild a caliper. But from what I'm reading it's a pretty common problem. I really don't care for the brake systems on these bikes. Haha

[Razorback]

I a

 

 

Sent from my iPhone using Tapatalk

[dvuch1]

Did a you fiddle with the pedal adjustment at all in the rear?

[Kevrg]

I did. And now come to find out I have no fluid reaching the front caliper? I tried to do the whole system bleed today and the front left caliper has no fluid flowing out of it when I bleed it.

[dvuch1]

I had adjusted my pedal a bit too much as well and the rear brakes started locking up...re adjust. Then re bled the system as it sounds as though it may be air locked in front....you did the fairing bleeder as well...I think you mentioned that ..good luck

[greg_in_london]

Sometimes before posting I feel I need to check that we're all talking the same language. You DO mean that you can't move the bike because the rear wheel won't turn and not that the brakes now work and lock the rear wheel when you use them ?

 

Good - Assuming that's the case..

 

Is the wheel locking solid ? If the problem is that the pistons have seized in place and you have now moved them out and they have not returned I'd expect the brakes to drag heavily, but not lock the wheel. In that case the brake would drag heavily, but I'd expect you to be able to turn it if you try hard. That would mean it will be hard to take the caliper off, but if you did, then using a g-clamp or piston compressor to repeatedly push it in and then pump it out again might get it working again - or if it's really cruddy / rusty you might need to polish or replace the pistons and generally refurb it.

 

On the other hand, it could be that the fluid return drilling in the master cyclinder is blocked, or the piston is not able to travel the full distance (did you say you'd adjusted the pedal - does it move through the full stroke ?) so that return hole might not be getting uncovered and the brakes are not being allowed to release.

In this case I would expect the same to apply to the front brake too though.

If the drilling is blocked, pushing the piston back in the caliper might clean it out.

 

To complicate things, there is also a metering valve to the front, which should not cause problems, and a proportioning valve (PITA) that can throw up random minor problems, but I don't think I've heard of it stopping the pistons from returning.

 

So - I'd check the brake master cylinder rod has its full travel and then make sure the piston in the rear caliper moves freely.

[Kevrg]

The brake is not entirely locking. It does locks just enough that I can't move the wheel by hand, so I have to bleed it again and then it loosens back up. Even when it's loose it still sounds like it's dragging just a little. I will try repeatedly compressing the calipers next and see if I have any luck with that. Thanks a lot for the words of wisdom!

[stickhandle2]

When bleeding the brakes

 

Front right caliper, bleed this with the front brake lever, ensure that you always have fluid in the reservoir on the handle bar by the front brake lever.

 

Front Left Caliper, this is bled by depressing on the rear brake pedal, make sure that you have fluid all the time in the rear reservoir

 

Back brake, use the rear brake pedal again make sure the reservoir is full

 

Bleeder at the top of the steering neck (under the Fairing) this is bled by pressing on the rear brake, if you find there is nothing coming out of it, the air may need some help getting up to the bleeder, put some weight on the rear brake pedal and leave it for a few hours, the air will eventually make its way up to the bleeder.

 

My 86 was a bit of a pain when I first got it as there was lots of air in the system and the fluid was real dirty.

 

Good luck

[utadventure]

You must have air trapped in the lines still.

 

You need to bleed the rear caliper, then the left front and last the bleeder by the steering head.

 

Good luck!

 

Dave