[def]

I'll throw my question in this forum as I figure this is where I can get some help.

I'm having some issues getting a proper bleed on a set-up w/ saint calipers and LX levers (brand new). I've got the front feeling like money, but I can't get the mush out of the back.....and I've tried every trick I know. (lever-to-caliper, caliper-to-lever, shimano bleeder, etc; all many times!!!)

I've never encountered this w/ any shimano set-up and I'm out of ideas. One thing that is unusual: the pinston in the master cyclinder takes a few seconds to return upon its first and second squeeze of the lever (<--this is difficult to describe). Once there is pressure in the system, it returns fine. I'm thinking this is my issue, but I'm hoping there is a way to bleed around this. Any ideas??

So, I ask any of the shimano nuts to come out of the woodwork and maybe offer me some advice. Thanks.

 

[SteezyWeezy]

take em to your shop, sounds funny, maybe a hole in the line, i have the exact same setup, lx with saint, rules

 

[Cave Dweller]

I find the same. I can get the front to feel so good, but the rear has a little mush and is never as good as the front.

I reckon it is the brake line flex, the rear has twice as much hose as the front.

 

[caputo1989]

fill the resovoure and put the caps back on. losen the bleed valve and pump fluid through. you will need to repeat several times. Then bleed the air out of the lines like normal.

 

[Boxxer]

Yea, sounds like something is wrong. I can bleed shims almost as fast as changing a tube, and it sounds like youre on the right track. Do you have the rear line routed in a way that air is trapped in it?(up/down loops can hold bubbles.)

 

[JohnnyC]

One thing that is unusual: the pinston in the master cyclinder takes a few seconds to return upon its first and second squeeze of the lever (<--this is difficult to describe). Once there is pressure in the system, it returns fine. I'm thinking this is my issue, but I'm hoping there is a way to bleed around this. Any ideas??

Wind the lever reach adjustment screw in until its sitting flush, I know this doesn't intentionally change the throw of the piston but it does help the piston return all the way. Bleed it through from bottom to top, close off the callier bleed nipple and pump the lever a few times. I've found sometimes you have to pull the lever back out the last couple of mm to get the piston fully returned. I used to bleed alot of shimanos and found this way worked really well


[edit]Do you suck air out of the calliper too? Pull back gently on the syringe at the calliper end to draw air out of the calliper too, often air gets stuck in the corners of the calliper and needs to be sucked out. Just be careful no to suck all the fluid out of the resovoir at the top, drawing more air into the system.

 

[JohnnyC]

I find the same. I can get the front to feel so good, but the rear has a little mush and is never as good as the front.

I reckon it is the brake line flex, the rear has twice as much hose as the front.

Yeah the rear lever of any brand of brake will always feel slightly mushier than the front. It shouldn't be a massive differernce but it will be slightly noticable. Some nice braided lines help quite a bit

 

[def]

Wind the lever reach adjustment screw in until its sitting flush, I know this doesn't intentionally change the throw of the piston but it does help the piston return all the way. Bleed it through from bottom to top, close off the callier bleed nipple and pump the lever a few times. I've found sometimes you have to pull the lever back out the last couple of mm to get the piston fully returned. I used to bleed alot of shimanos and found this way worked really well


[edit]Do you suck air out of the calliper too? Pull back gently on the syringe at the calliper end to draw air out of the calliper too, often air gets stuck in the corners of the calliper and needs to be sucked out. Just be careful no to suck all the fluid out of the resovoir at the top, drawing more air into the system.

Thanks for the lever hint. I think this may be where the issue is. Last bleed I was able to get 2-3 tiny bubbles out from behind the piston and I think this is where my air pocket is, I just can't get it out.

I haven't been backing off the syringe, but still removing a bit from the caliper. BAsically, using the open-squeeze-close-release method hopes taught me years ago.

 

[def]

Yeah the rear lever of any brand of brake will always feel slightly mushier than the front. It shouldn't be a massive differernce but it will be slightly noticable. Some nice braided lines help quite a bit

Its a big difference between front and rear. I had been thinking about some goodridge lines, but if my problem is in my lever I won't be treating the correct sympom. By the way, the lines are brand new w/ no kinks or whatnot.

 

[spoke80]

Its a big difference between front and rear. I had been thinking about some goodridge lines, but if my problem is in my lever I won't be treating the correct sympom. By the way, the lines are brand new w/ no kinks or whatnot.

sounds like someone sold you some bunk gear

 

[manhattanprjkt83]

I found the trick to bleed shimano is to fill the lever with the caliper closed. Pull in the lever and while it is pulled open the caliper once the fluid with preasure on it pushes out close the caliper with the lever still depressed.

It will suck in the fluid lost while forcing out any air. I used this meathod last weekend and my brakes are rocks. Took me about 4 bleeds to get my saints where i wanted them but once they are in place they are really reliable.

 

[dante]

bleeding saints?

 

[OGRipper]

^^Hahahaha, nice one Dante!

Lots of good tips, here are a couple I didn't see yet:

If they are new old stock that came with complete, you might benefit from flushing out all of the fluid and replacing it with new stuff.

Another trick is to hang the bike with the caliper on the bottom and the lever on top for a day or so, to let air bubbles rise up to the lever. Keep at it, there is probably nothing mysterious going on and eventually you'll get it.

 

[in the trees]

Was the brake bled while mounted on the bike? I had to remove a Hayes rear brake once because after repeated bleeds it still felt like **** - air trapped in the lines as it was routed along the frame. Removed it from the bike, and the problem was fixed with the next bleed. Might be worth a shot.

toby

 

[davep]

I find that it helps to 'tap' the caliper and lines with the handle of a screwdriver sometimes to get little micro-bubbles to move up the hose. With my hopes, I have also had some air trapped behind the master cyl piston and find that a few quick lever snaps with the caliper closed seems to knock the bubbles loose.

In general when doing the bleeding from the top down (squeeze, open, close, release, repeat) I find it imperative to squeeze the lever HARD and crack the bleed nipple in a very quick motion, then repeat immediately a few times....the idea is fluid velocity..the faster the fluid is moving, the more it will scour out any air and push it down and out..repeating is needed to keep any bubbles from moving back up before they are eliminated.

If your piston reamins sticky, remove it and lube the seal/o-ring with some silicone grease..avail at most hardware/plumbing stores.

 

[Cave Dweller]

Yeh, johhny C it's not a big deal but i can feel it. I also think that the newer shimano resin lines that came with my saints are not as good as the older resin lines i have on my xt 4 pots. My xt 4 pots feel firmer then my saints and they get the same bleeding treatment.

I find that it helps to 'tap' the caliper and lines with the handle of a screwdriver sometimes to get little micro-bubbles to move up the hose. With my hopes, I have also had some air trapped behind the master cyl piston and find that a few quick lever snaps with the caliper closed seems to knock the bubbles loose.

I dont know about the rest of you, but when i bleed my brakes a set will take me about 2-3 hours.

Pushing fluid in is piss easy and takes all of 10 mins with a big syringe at the brake end, the long bit is doing what dave says and tapping the lines to get ALL air bubbles out and squeezing the brake lever a billion times. I just grab a beer and watch some TV while doing it. Those guys that say they can do it in a couple of minutes must do a fairly crappy bleed and i wouldnt let you near my bike

 

[kidwoo]

There's not much difference between my front and rears. I've got complete sets on 3 bikes and a rear on my dj and they're all just as crisp and strong as each other.

The only thing I've had to deal with is a bad bleed so I can't offer any opinions on piston replacement. Relying on the longer hose argument to justify a drastically differently behaving rear brake just doesn't jive with the ones I've got. There's got to be something else going on.

 

[def]

sounds like someone sold you some bunk gear

I know where he sleeps.



Thanks for the suggestions. I gave it another go this evening w/ the same results. The lever feels okay w/ the yellow block in there, but then all to mush w/ the wheel and rotor fitted (I've checked the fit w/ the rotor too - and its perfectly straight and plumb). I guess I'm down to finding a schematic (sp?) and tearing apart the lever or trying to warranty an unused part not from the original owner.

I had the fear I've lost my touch, so I set up the dork bike tonight and rebuilt a mutt set of old hayes from my parts supply.....both bleed out perfectly w/ only one try.