Resolved: Saint Brake Levers Leaking

[Kever]

So my 2010 Saint levers have started leaking mineral oil and I don't know why or where it's coming from. This is also happening with one of my friends saint brakes. I've recently put the "heavy mineral oil" laxative that you get in the drug store in my brakes, could this be causing the leakage? Any difference between that mineral oil and the pink shimano stuff? Any remedy for the lever leakage? The reservoir is topped up to the brim, and the brakes perform well (ie. consistent lever pull, good power). Also the brake fluid is pretty discoloured, I think it's time for a flush. Anyone know where to buy thin surgical tubing?

[treorwg]

Shimano's instructions say not to use drugstore mineral oil, but don't say why. It could be additives they use, or maybe a difference in the viscosity.

If you flush with the Shimano stuff, that might fix it. Let us know either way if you don't mind, I'm curious now.

As a bonus, the Shimano fluid comes with a piece of tubing.

[Spinach]

ha.
By the sound of it, you don't have a bleed kit...either way, I strongly recommend taking it to your bike shop of choice. You could be in need of some new seals, and it definitely sound's like you're in need of a proper bleed.....

[Kever]

Originally Posted by treorwg

Shimano's instructions say not to use drugstore mineral oil, but don't say why. It could be additives they use, or maybe a difference in the viscosity.

If you flush with the Shimano stuff, that might fix it. Let us know either way if you don't mind, I'm curious now.

As a bonus, the Shimano fluid comes with a piece of tubing.

Thanks for the info dude. I'll try bleeding it and posting up with results.

[Kever]

Originally Posted by Spinach

ha.
By the sound of it, you don't have a bleed kit...either way, I strongly recommend taking it to your bike shop of choice. You could be in need of some new seals, and it definitely sound's like you're in need of a proper bleed.....

I can bleed a brake just as well as a bike shop, and I won't have to spend $60. If I need new seals then it will probably be cheaper just to buy a new brake. But I won't buy a new brake because it will be much cheaper just to keep the reservoir topped off.

[C.Lee]

Originally Posted by Kever

I can bleed a brake just as well as a bike shop, and I won't have to spend $60. If I need new seals then it will probably be cheaper just to buy a new brake. But I won't buy a new brake because it will be much cheaper just to keep the reservoir topped off.

with those saints, you dont really need shimano bleed kit with aluminum clamp and such. Just a small mineral oil bottle to top off the reservoir and wrench to unscrew the bleed nipple and drain bottle.

[leggatt]

If it is leaking from the reservoir cap, you can get a new gasket cheap enough. I doubt the seals are wrecked, but I would flush the system with the Shimano fluid. It is a much lighter weight and the brakes will perform way better with the correct mineral oil.

[Timmigrant]

I know of some other guys that have had issues with the main piston seals degrading and mineral oil leaking out of the master cylinder on those Saints.

[zofmg]

I used the cheap mineral oil from the pharmacy as well because shimano's stuff is a money grab. Bled the brakes, worked well for months until the past couple days, I then looked at my pads and they were just about dead. No leakage though.

I think your issue is that you're flooding the system because as the pads wear the more leverage you loose on the leaver(that's what the adjustment knob is for), as you keep adding mineral oil to the system the more pressure is pushing the seals out to keep the pads closer to the rotor and risks damaging the seals.

^I know this because a friend of mine had the same issue with his formula one's and blew them up at whistler... Anyway, my guess is that you're having the same issue (except for the fact that he used formula branded brake fluid )

Check pad life, bleed it, constantly check for air bubbles (flicking the lines with your finger helps) close er up and you should be set.

Go to Canadian tire and visit the plumbing section and you should find one, pick up some brake cleaner, or alcohol, and spray down the calliper.

Cheers, good luck.

[Kever]

Thanks for the tips, I'll post up how it goes.

[Kever]

Originally Posted by zofmg

I used the cheap mineral oil from the pharmacy as well because shimano's stuff is a money grab. Bled the brakes, worked well for months until the past couple days, I then looked at my pads and they were just about dead. No leakage though.

I think your issue is that you're flooding the system because as the pads wear the more leverage you loose on the leaver(that's what the adjustment knob is for), as you keep adding mineral oil to the system the more pressure is pushing the seals out to keep the pads closer to the rotor and risks damaging the seals.

^I know this because a friend of mine had the same issue with his formula one's and blew them up at whistler... Anyway, my guess is that you're having the same issue (except for the fact that he used formula branded brake fluid )

Check pad life, bleed it, constantly check for air bubbles (flicking the lines with your finger helps) close er up and you should be set.

Go to Canadian tire and visit the plumbing section and you should find one, pick up some brake cleaner, or alcohol, and spray down the calliper.

Cheers, good luck.

I think I might have flooded the system. The pads wore down, I added fluid, then I spread the pistons and put new pads in without opening the reservoir. Doh. Hopefully no seal damage.

[Kever]

So my levers were leaking from the reservoirs because there was too much fluid in them. Next time I will open the reservoir before changing pads. I tried bleeding with drug store mineral oil but it was too thick and the engagement point was different every squeeze. I rebled with shimano oil which is super thin (and super expensive) and the brakes work great. You could probably get away with drug store mineral oil if you can find one that's thin enough. That being said, I'm sure shimano uses a specific viscosity to maximize performance so you're probably better off going with that.

[heckler13]

I've been using magura mineral oil with my shimano brakes for a long time with no issues because its cheaper (at least here in the states).