[moon]

ey op,
Having dismantled the front caliper ('91 TA) & stripped it down & cleaned it up & put it back together again & refitted it & all that, It's a right b*tch to bleed. I do know how to bleed brakes (in theory) & I've got a proper wee gadget pipe thing with a non return valve in the end immerged in the liquid, but I dont seem to be able to get all the air out. If I do it by pumping the lever, holding it in & releasing the blees nipple, I get no signs of air (except that the lever is all spongy). If I do it using the special pipe thingy there's loads of air, but there seems to be no end to it...

can any one think of something I might be missing? or doing wrong?

Ta

Moon

 

[Whealie]

Did it on my @ recently. If you have drained out the system and are filling from scratch it simply takes a long time. Just when you really think it cannot be working the lever starts to stiffen and you get those last few bubbles out. That last stage happens quite quickly but it does seem like very little is happening for quite a while. I had my son sitting on the bike doing the lever and he got sore fingers it took so long.

 

[Xander]

Did it on my @ recently. If you have drained out the system and are filling from scratch it simply takes a long time. Just when you really think it cannot be working the lever starts to stiffen and you get those last few bubbles out. That last stage happens quite quickly but it does seem like very little is happening for quite a while. I had my son sitting on the bike doing the lever and he got sore fingers it took so long.

that sound right to me... it takes a long time..

you are keeping the master cylinder full right? once it gets too low you just sucked more air in...

patience young jedi ..get there you will...

 

[Wee Jack]

patience young jedi ..get there you will...

LOL

 

[snapper]

Get a mityvac! I got one from Hein Gericke online I think for about £35 (41 now). Now takes about 2 mins to bleed fully. Can't reccomend it enough!

http://www.hein-gericke.com/uk/product_info.php/products_id/1708

You just attach it's conncter to the bleed nipple, pump to create a vacum and release the valve, it just draws fluid through from the MC res so you just keep topping it up as it draws through, easy as, even on your own.

 

[moon]

Get a mityvac! I got one from Hein Gericke online I think for about £35 (41 now). Now takes about 2 mins to bleed fully. Can't reccomend it enough!

http://www.hein-gericke.com/uk/product_info.php/products_id/1708

You just attach it's conncter to the bleed nipple, pump to create a vacum and release the valve, it just draws fluid through from the MC res so you just keep topping it up as it draws through, easy as, even on your own.

I've had the bike 6 years, this is the first time I've bled the brakes meself so 40£ odd ain't very cost effective if there's another way of doing it.

BUT, thanks for the idea cos at work I've got a peice of kit that is more or less a bigger version of that & it may just do the job.

 

[Whealie]

£1.50 bit of plastic hose and a small glass jar once you've eaten all the jam. And the smallest bottle of brake fluid cos it don't take much.
The one thing you need a lot of is patience.
To put it in context, my cylinders were stuck in, so I used the brakes to ease one side out, cleaned them and put in new seals and refitted them, Bled the brakes and then did the other side and repeated the whole exercise, bleeding the brakes again.
It helps have children young enough to do as they told but old enough to actually help. They can just sit there and do the pump, pump, pump, squeeeeeeeeze on the brakes while you sit there holding a spanner in one hand and the glass jar and tube in the other.

 

[Slimie]

£1.50 bit of plastic hose and a small glass jar once you've eaten all the jam. And the smallest bottle of brake fluid cos it don't take much.
The one thing you need a lot of is patience.
To put it in context, my cylinders were stuck in, so I used the brakes to ease one side out, cleaned them and put in new seals and refitted them, Bled the brakes and then did the other side and repeated the whole exercise, bleeding the brakes again.
It helps have children young enough to do as they told but old enough to actually help. They can just sit there and do the pump, pump, pump, squeeeeeeeeze on the brakes while you sit there holding a spanner in one hand and the glass jar and tube in the other.

That's a window of about twenty minutes nowadays, I suspect!!

I'm still bleeding the brakes on a bike, over and over again - so far I've pumped through two 150ml bottles and it's still soft.

I've tried tying the caliper up high to get the bubbles to rise and I've tried zip tying the lever to the bars so that the air can get out that way.

Now I plan ahead to take into account the slightly longer stopping distance!!

Keep trying, unless you have a leak you will get there in the end.

-Simon

 

[Jenna]

check all the joints, make sure that the banjo's that should have copper washers have got them and that they are sitting properly. If you do want to invest in a mity then I will back up that they do work well ( been using one for 15 years!), however if your tight then a plastic pipe in a jam jar still works (but if you add a bit of rubber pipe with a ball bearing in it on the end it works better as you have back pressure! )... some systems take forever to bleed and if your sure its assembled right it may well be a try, try and try again situation.

 

[DaveS]

Nobodys mentioned the elastic band trick yet!
Leave the master cylinder cover very slightly off.
Using an elastic band hold the lever open and leave it overnight.
Come back in the morning to find all the air gone.

If that fails try moving the caliper about as air is obviously trapped somewhere and you need to dislodge it somehow.

 

[moon]

try, try and try again situation.

Hummm that's an interesting concept, at work when one of the boats stops working my technique has always been "if at first you don't succeed, HIT IT WITH A BIGGER HAMMER!"

:evil4:

 

[Grader]

Most important thing is to minimise areas where air can get trapped and bypassed by the bleeding process, the biggest being behind the pistons.

To avoid this I G clamp all the pistons (all 4) as far into the caliper as they will go before attempting to bleed, this makes a huge difference in the speed of the bleeding process.

I also fitted speed bleeder nipples that have non return valves built in that mean that at the start of the bleeding process you can just stick a bit of clear pipe on and pump away. I finish off by doing the release-squeeze-tighten-release-repeat process just to be sure.

 

[Slimie]

Nobodys mentioned the elastic band trick yet!
Leave the master cylinder cover very slightly off.
Using an elastic band hold the lever open and leave it overnight.
Come back in the morning to find all the air gone.

If that fails try moving the caliper about as air is obviously trapped somewhere and you need to dislodge it somehow.

Ahem...

I've tried tying the caliper up high to get the bubbles to rise and I've tried zip tying the lever to the bars so that the air can get out that way.

:-D :-D :-D

Sorry Dave!!

 

[barftone]

Nothin worse than bleeding nipples!! Get a mityvac and stop messing around. Good tool that will last for years.

 

[sbikerbud]

when i did the brakes on my VFR i found i had the same troubles as the original poster.

I found that if I bled it as much as i could (lever would still be "soggy") then took the caliper off the fork leg, let it pump the pistons till they were virtually fully out.

Left the caliper to sit on a bucket with the brake hose straight for a while.(an hour or so....until i could move my fingers again )

Then tied the lever back, and used a G clamp to slowly push the pistons back in (watch the fluid level because it will all spill over the top of the res' )

The amount of fluid behind the pistons was enough to push any remaining bubbles back up the pipe to the reservoir.

Lever was "solid" after that.

 

[Guest]

Try doing the front brakes on a GPz900. Damn thing has 6 bleed nipples just for the front system!!! (2 on the callipers, two on the anti-dives and 2 on the unions between the brakes/anti-dives)

Kymmy

 

[moon]

thanks for the tips boys & girls, I thought i'd try the easiest first, opened the master cylinder, pumped a few times & bungied the lever back to the bar. Left it 24 hours, &...miracle of miracles, it seems to have worked, I can't decide if there's still a little "give" in the lever or not, but it's certainly no worse than before I started messing...

:thumbup: I'll have to go & try it on the road this afternoon.

 

[Slimie]

Woo Hoo!!

That is all.

-Simon

 

[moon]

Nope , not all, although it seemed to have done the trick, whilst riding it's obvious that there's still air in there somewhere. Have re bled using a homemade kit & it's better but not 100%

What's the top bleed by the master cylinder for? bleed that first or last?

I may well have another go this evening.