After treating my bike to a proper clean, both my Saint brakes levers are now full on floppy,so pretty sure the hydraulic pistons in the levers are both fekked. I didn’t realise Fenwicks was so lethal, usually I just use a little soapy water. The pistons were very sticky too, but I’ve freed them up.

I’m looking up how to overhaul Saints, seems a bit tricky but worth a go. They were 100% fine before, even though they are 5 years old and been through a lot.

One suggestion was to soak them in diesel or petrol…?

Assuming I balls this up, can you use an XT lever with a 4 piston Saint caliper? Seems that the lever might not push enough fluid and its stroke would be very different?

Thanks

It’s hard to see how cleaning it could have affected the brakes unless you blasted it with a pressure washer. Bearings and brake levers aren’t designed to be blasted with high-pressure so that tends to blow dirt past the seals and wrecks things. If this is what happened, it’s not the cleaner that you used, it’s the careless use of a pressure washer.

One suggestion was to soak them in diesel or petrol…?

I would not put petrol near brake cylinders. Hot soapy water would be my first choice, followed by hot fresh water.

AFAIK, all Shimano levers are cross-compatible, it’s just a matter of getting the correct hose fittings. Getting more power from 4-pots generally involves having a larger piston area with the same size master cylinder. They don’t use a larger master cylinder, that would defeat the purpose.

Nope, no pressure washer involved. No bearings either.

I too really can’t see that cleaning them with Fenwicks is the root of the issue. 🤔🤔

I remember 18 months back that a mate got his bike out of the garage after putting it away the night before and everything worked. Before the end of the road he only had one working brake (same symptoms as you).
They weren’t Saints but where Shimano

If yours are 5 years old, maybe they’ve just decided thats it and unfortunately failed both at the same time.. and it just happens to be convenient for you to point the finger at a brand of cleaner without any real evidence

Did you turn it upside down to wash it? If there is air in the master cylinder reservoir that can get into the master cylinder when you turn the bike over or lay it on its side. If that’s what’s happened, bleeding and topping up the fluid should probably fix it.

Yeah – I know this sounds weird, but for both brakes to have the same issue simultaneously (Carlos!) then I am looking for a cause, something different that has happened since I last rode it. Sorry – this wasnt supposed to be an anti-Fenwicks rant, more surprised and looking for advice. I’ve never let GT85 get near my brake levers and wondered if Fenwicks might have the same issues?

These brakes have been faultless for 5 years (according to Strava – around 15k km and over 500k metres of descending). Highly improbable they would both choose to pack in on the same day and in identical fashion.

We’re not just talking ‘sticky’ , but full on stuck. Anyway, regardless of the cause, any other views on whether a standard XT or SLX level will do the job if I keep the Saint callipers.

thols2 – yes, I often invert the bike without issue. I cant bleed the brakes as the reservoir is blocked off by the stuck master cylinder piston. But even if there is air in there, the levers shouldnt be floppy, the plunger (?) should have retracted and pushed them back out.

Might be the hot weather – if there is air in the cylinder and it’s expanded.
Try bleeding from the caliper.

I wondered about that, but the bike was stored in a fairly cool shed. They won’t bleed from the caliper as the lever end is totally sealed off. Can’t even draw on the bleed port with a syringe. Weird one.

Sh*tmano can be affected differently. I’ve got a box filled with old shimano levers have failed for different reasons. The last set were off a DH bike that had little use- both failed at the same time after being sat for a while despite being bled frequently. Just bought some Zee levers, this sorted it. Till the next time.

Where did you get the Zee levers, that’s probably a relatively cheap solution for me

You haven’t actually described what’s wrong with your brake levers – or your brakes. First you said “they went full on floppy”, then you said “They were stuck on”, and then you said “the lever end is totally sealed off”.

Brakes aren’t that complicated; it’s a piston at one end with some seals and something to push on it, a cable, then an open bath caliper at the other end with two bigger pistons that press on the pads. You have broken one of the above, or you have air trapped that’s preventing the above from working.

Sadly I got drawn in here by your absurd title, but here I am.

Fenwick’s cleaner killed my Saint brake levers

Sorry – this wasnt supposed to be an anti-Fenwicks rant,

Just as well you cleared that up then because that’s how it looks 🤷‍♂️

There’s not much to dismantling the lever and checking, youtube have a few videos up about this, you can then remove the piston, check it and make sure no grit or rubbish has got in, then bleed it from the caliper.

If it’s just spongy, then best thing to buy is one of the little shimano funnels, screw it in and just bleed it over a little while to get any air up and out the system.

I’ve had hoses clog up on old Saints, similar to the above, couldn’t push fluid through. Had to dismantle them, the blockage was around where hose joins caliper, blew out all the parts with a compressor and got them going again, but they didn’t last much longer, I think the blockage was bits of seal that had started to break down internally. They started to leak soon after and levers needed replacing.

You could try hope brakes instead? You would have to put up with completely ineffective brakes of course, but they can be rebuilt, so I’ve heard.

Wow, STW posse went full STW on that one. Chill time everyone, it’s hot out.

You can run XT or XTR levers with Saint calipers, we are running both on a couple of bikes with no problems

The pistons were very sticky too, but I’ve freed them up.

What exactly did you do to free up your sticky pistons? Anything you could do to “fix” this would seem, to my ham fisted brain, to be infinitely more likely to end up shagging your brakes than just giving them a good wash.

If you disconnect the brake hose you can push back the sticky master cylinder piston. (2mm allen key or similiar)

Shimano master cylinders are not designed to be serviced, but you can take them apart with a bit of care. If they seals are swollen from some kind of solvent the problem is sourcing new seals.

You haven’t actually described what’s wrong with your brake levers – or your brakes. First you said “they went full on floppy”, then you said “They were stuck on”, and then you said “the lever end is totally sealed off”.

Sounds like the piston is stuck down the bore in the master cylinder, as those shimano brakes use a linkage this gives a floppy brake lever, with the brake stuck on.

To me is sounds like the master cylinder seals have swollen and won’t let the piston return. If they are the levers I’m thinking of there is no “direct” connection between the master cylinder and the lever i.e pulling the lever back out doesn’t actually pull the piston.
I’ve had a few do this when they’ve been gunked up – I’m pretty sure I replaced my XT lever with a Deore one a few years ago with no issues