bleeding brakes

[fjbiker84]

It shouldn't be this hard!!!  I got new seals installed in my left front caliper and bought a brake bleeding kit that advertised it was for cars or motorcycles.  Anyway, I'm sure I hooked it up correctly.  Can build good pressure in the brake bleeder, then open the valve on the caliper briefly, pull fluid thru, close the valve, repeat.  Have run enough brake fluid thru the system to fill the collection cup twice but still no pressure in the lever (actually there is enough pressure to push the caliper pistons out such that the brake pads have seated against the rotor).  But the brakes are still inoperable.  Is there something I'm missing?  I bled the caliper on the right side even though it was not worked on.

[Pat Conlon]

Start at the furthest bleeder from your m/c. That would be the left side anti dive, then the left caliper, then the right side anti dive, finally the right caliper.

You have the right tool. Those vacuum pumps are the bomb. I put some Teflon tape on the threads of the bleeders. Helps keep air bubbles from entering at the bleeder.

You should be getting pressure. Did you take the splash plate out at the bottom of the m/c reservoir and clean out the gunk below the plate?

[fjbiker84]

Thanks, Pat.  I'll try going in that sequence.  I have taken that splash plate out in the past and cleaned the reservoir but have to admit I didn't do that this time.  Will try that too.  Interestingly, I went down to Del Amo Motorsports (closest Yamaha dealership) today and talked to the service manager about my situation.  He said they wouldn't even try to work on a bike this old.  He said there was no telling what parts may be required and no longer available.  I started to argue the fact that the brakes worked fine before this work, the master cylinder had been rebuilt recently and the parts are readily available but decided to leave the conversation at that.  He did refer me to another bike shop (Hudson Motorcycles in Gardena) and I went over to talk to them. They were very helpful and offered to help me out if I couldn't resolve it myself. Not crazy about driving without front brakes but I guess if I'm careful it would be doable.

[Pat Conlon]

When you re-assembled the brake lines did you remember to use new crush washers?

Looking at your picture, I see 1 crush washer, but I don't see the other 2.
The double banjo needs 3 crush washers.
1 at the caliper, 1 between the two banjos, and 1 at the top of the banjo bolt.

Aluminum crush washers deform (crush) when first tightened. You should not re-use them.
I have heard of folks taking a butane torch and re-soften the aluminum washers so as to reuse them, but I have not done that. They're cheap. I use them once then throw them away.

[red]

FJbiker84,

You may still have an air bubble at the top of the brake line.  Do the bleeding again, as suggested above, but when finished, pull the brake handle and tie it hard against the hand-grip with bungee cord (or any cord) for the night.  In the morning, work the brake handle slowly, and you might want to watch inside the MC for air bubbles to come up.  Repeat as necessary, it may take several nights with the brake lever tied each night.  I will never understand why there is no bleeder at the top of the front brake line, on every bike made.

I have not used the pump set-up, but I use SpeedBleeders.  Once you get the caliper full and you have just a little braking action, they are a great help, with no pump needed.  They will not allow an empty caliper to fill up, though, so you would probably need a regular bleeder screw to get things started, for the first time.  I really like them, for replacing brake fluid normally, unassisted.

Cheers,
Red  

[copper]

Turn the handlebars to the left to level the master cylinder. If not the hose connection is higher than the bore and will hold air bubbke

[Alf]

Home made bleeding kit

[balky1]

You should have filled the empty calipers with brake fluid first with a syringe and then you would manage it by old method without any probs. I bled my clutch that way in under 5 mins while I read here a lot of people struggle with it.

[4everFJ]

Home made bleeding kit

Nice 

[FJ1100mjk]

[fjbiker84]

Thanks for the recommendations.  The washers are in place correctly but I'll admit that they are the same washers that were put on the bike when I replaced the brake lines 10 years ago.  So I need to replace those.  The fellow at Hudson Motorcycle mentioned the thing about trying to build pressure with the brake lever and then securing it to the handlebars over night.  Will try that too. 

[fjbiker84]

Just a few other observations:  I did try filling the caliper with a syringe prior to installation.  That was an idea I heard about (after giving up and taking the bike to a shop) several years ago when I ran into this same issue. I know the issue is with the caliper.  I have replaced the brake lines in the past and had no problems - rebuilt the brake master cylinder a while back and no problems there, too.  And I've installed new clutch slave and master cylinders seals several times and been able to get the system back up and running - no problem.  But several years ago after coming home with my rebuilt calipers I was never able to get pressure in the front brakes - same deal as now.  Ended up having to ride the bike - without front brakes - to a Yamaha dealer (I lived in a different part of LA) to get their help.  I don't know if other models have this same issue because I don't have any experience in that regard but it's my opinion that Yamaha didn't design the bleeder valve on this model entirely right.  For those of you who haven't rebuilt your caliper seals before - this step is a bitch!  I've added one more picture to show why I ran into this issue in the first place. The seal installed several years ago failed - bad seal has small tear in it compared to new.

[fjbiker84]

It worked!!  Early this morning I went down to the garage and pumped the brake lever several times and then tied it to the handlebar.  This afternoon I released the tie and checked for brake pressure in the lever - and I've got it!  Don't know why but this works.   

[chiz]

don't care what anybody says    bleeding hydraulics on a bike is a bleeding nightmare always has always will and no one has come up with a believable explanation why. Some folks might get lucky but generally its a bloody ordeal!
  I quake in my boots and cry whenever it has to be done hate it

[GS Jockey]

don't care what anybody says    bleeding hydraulics on a bike is a bleeding nightmare always has always will and no one has come up with a believable explanation why. Some folks might get lucky but generally its a bloody ordeal!
  I quake in my boots and cry whenever it has to be done hate it

That pretty well sums up the way I used to think about brake bleeding, I couldn't get it to work no matter how much I tried, following the way I'd seen others doing it. So I stopped and had a think. And a smoke, and a coffee. Several smokes and coffees in fact. And my thoughts ran thus:

What do we know about air in a system? It 'likes' to rise to the top. OK, so let it. I set the bars so that the reservoir was at its highest point, with the brake line running as close to vertical as I could get it, from calliper to M/C. I then left it for a while, over night in fact. I did not tie back the brake lever, no need to.

Next day, I started by ignoring the callipers initially, just worked on the master cylinder. I removed the master cylinder cover and rubber gasket, made sure the fluid was topped up, then slowly pulled back the lever, watching what happened in the reservoir.

Two holes in the bottom revealed the piston moving right to left in the cylinder. When the piston cleared the hole to the left, I think the smaller of the two, air bubbles came out of it. As the piston closed off the hole, the air bubbles stopped. So, I released the lever, smoothly as opposed to fast, and repeated. Again as the small hole was 'opened', air came out. This time I didn't continue until the hole was closed off, just waited until the air stopped coming out. It took maybe six or seven 'pumps' of the brake lever, and suddenly I had full brake pressure. Simple as that. If you have only 'partial' pressure at this point, then it's time to move to the calliper(s).

People I'd watched bleeding brakes in the past had fitted the plastic tube over the bleed nipple, opened the nipple then pumped the brake lever rapidly until the reservoir needed topping up, then closed the nipple. I tried this many times without success, which was when I stopped to think about it. As well as thinking about what air in a system likes to do, I thought about what was happening in the system as a whole.

OK. Open the bleed nipple, and pull back the lever. Fluid is forced through the hose, and out of the nipple. Release the lever... and what happens? Well at the reservoir end, fluid flows down in to the cylinder. But not straight away!. It can't flow in to the cylinder until the piston clears the small hole on its return stroke, by which time it has travelled backwards maybe 1/4 inch. During this 1/4 inch of travel, the pressure in the system is released, and in fact becomes 'negative', thus allowing the atmospheric pressure at the open end of the bleed tube to force air back along the tube, and back in to the nipple. So each time I pumped the lever, when I released it maybe half of the expelled air was being 'sucked' back in. I'd get there eventually, but it was hard work.

So I slowed the whole action down a bit:

• Open bleed nipple.
• Pull back lever, observing any air coming from nipple.
• CLOSE BLEED NIPPLE
• Release brake lever.

Repeat this until no more air is expelled from the nipple, always ensuring the reservoir doesn't empty. Once no air is coming out, close the nipple and pull in the lever. If you have a single calliper, you should find you now have full pressure. If you have a twin brake system, repeat this procedure on the second calliper.

Some of you may not agree with this method, or believe that it works. That's up to you. I just thought about it logically, and applied a method that should work according to that logic.  I first tried this method back in 2000, having had to strip, clean and re-build the front callipers on my first FJ. It worked then, and has worked first time every time since, including on my BMW R1100 GS with ABS brake system.

No 'Auto-Bleed' system of any kind was used, just a 10mm ring spanner on the bleed nipple, along with a length (maybe two feet) of clear plastic tube attached to nipple, and a receptacle to place the other end of the tube in to catch excess fluid.

Sorry this has taken a while to read, it took much longer to explain than to actually do. But if it helps folks like Chiz, it is worth being long winded.

*I do have to add that this thread was started by a member with the 'Anti-dive' system fitted, an 1100 or early 1200. I have never had the pleasure of working on such a system, and my method above would need adapting for this situation.

Looking at the set-up, I'd probably try starting by bleeding the right-hand caliper, followed by the right-hand anti-dive. Then move over to the left.

I have no idea if this would work!