bleeding rear brakes - the wrong way around!

[Noggin]

Ok, I'm kak-handed, so am going to struggle to bleed brakes.

I've been told that using a syringe and bleeding them from the caliper end would be easier/better

Does that sound right?

Any hints? I have a big syringe, brake fluid and time. Just need some advice before I head off to actually attempt it !!

Only going to attempt the rear as the front worked fine (last time out!!)

[A_morti]

Some bikes can be a pig to bleed the rear brake, e.g. if the caliper is lower than the spindle then you may have high/low loops in the hose. I think that's the case with your Monster? If so then it's definitely a good idea to try reverse bleeding.

Depends how long it was since the caliper was rebuilt and how involved you want to get, but if you're doing fluid anyway then it would be a missed opportunity if you didn't remove the caliper off the bike, pump the pistons out, clean everything, remove the old dirty fluid residues etc., and put it back together nice n clean, ready for another winter's service.

If I do remember right and you have an old Monster, you may need an 11mm spanner to open the bleed nipple. Worth checking before you actually go to do the job, just in case you don't have one around already!

[Supermofo]

Advice on brakes. Sorry none as I've the mechanical ability of a mentally challenged hamster

Advice for Noggin. Call an ambulance for standby as you're bound to end up with the bike on your head or something

[Noggin]

Some bikes can be a pig to bleed the rear brake, e.g. if the caliper is lower than the spindle then you may have high/low loops in the hose. I think that's the case with your Monster? If so then it's definitely a good idea to try reverse bleeding.

Depends how long it was since the caliper was rebuilt and how involved you want to get, but if you're doing fluid anyway then it would be a missed opportunity if you didn't remove the caliper off the bike, pump the pistons out, clean everything, remove the old dirty fluid residues etc., and put it back together nice n clean, ready for another winter's service.

Thank you. Demannu did the brakes but a couple of years ago now and I did ride in November the first year I had it here!! So I might try that. Might be a bit above my skill level, but I'll have a look!!

[Noggin]

Advice on brakes. Sorry none as I've the mechanical ability of a mentally challenged hamster

Advice for Noggin. Call an ambulance for standby as you're bound to end up with the bike on your head or something

TBF, I think they are always on standby when I'm here!!

[A_morti]

Nicked your image.

If you try to bleed that "normally" by pumping fluid from the reservoir through the caliper, gravity says the caliper body will drain of fluid and fill with air instead, so yes reverse bleeding is a good option. Or if you wanted to do it normally, take the caliper off the bike and keep it above the hose such that the bleed nipple is the highest point, while bleeding. Not as hard as it sounds if you have assistant. You may find it can be zip tied or even bolted to the exhaust hanger for that purpose, then you could do it without a helper.

Those caliers are pretty good quality, the pistons are aluminium so cannot rust. Even so it doesn't hurt to give it a spruce up while you're in there.

[JackyJoll]

Have you already tried doing it the normal sort of way?

[A_morti]

btw - DIN7984 is the standard for low headed Allen bolts, just in case you wanted to give that a bit of a shine. I did that before on the bolts of a Mito front caliper, fitted on a Grom!
No clue what exact size you need, sorry. Was ages ago.
https://www.ebay.co.uk/itm/363471817731

[dern]

I would just follow the procedure outlined in this video...

If your brake system is full of fluid and your goal is to service them them you're not bleeding air out of the system, you're changing the fluid. I assume that that's your intention. If you find you are bleeding air out of the system then there's something wrong with the system and you need to get that fixed. There's no way that air can get in to the system even if the fluid is old unless a seal or something has gone and then you're likely to have fluid coming out of somewhere.

I can't see any benefit to reverse bleeding unless your system was empty and you can't shift the air out of it. One downside of reverse bleeding is that it will frequently pull air past the bleed nipple making you believe that there's air in the system, which there probably isn't. You can mitigate this by taking the bleed nipple out and wrapping ptfe tape around the thread near the nut (not on the point sealing end) and then reinstalling it. However by doing this you'll definitely introduce some air and you'll need to bleed that out.

Doing the rear is good practice for doing the front but I wouldn't not to the front. Brake fluid will degrade over time and your brakes will always work fine the time before the time that they don't work fine for the first time. I change mine every year, most people change it every two. I just don't like to see darker fluid in the reservoirs.

[dern]

If you try to bleed that "normally" by pumping fluid from the reservoir through the caliper, gravity says the caliper body will drain of fluid and fill with air instead, so yes reverse bleeding is a good option. Or if you wanted to do it normally, take the caliper off the bike and keep it above the hose such that the bleed nipple is the highest point, while bleeding.

That's not true as the pressure you're applying to the fluid through the lever pushes the fluid out and it can't be replaced by air if you close the bleed nipple while applying pressure. If you stop applying pressure and then close the nipple then there's a possibility that air can get in.

[DefTrap]

With brake bleeding, after you've taken parts of the system apart for cleaning (and you should), the worst bit is priming the system (as in getting enough fluid in the lines so that you can start to bleed it). I always put a longish bit of clear house (you will see why this may be important) on the bleed nipple and suck the fluid through til it starts to flow reasonably consistently. If there's no leaks in the system, you won't have to suck much. If you have to suck so much that there's any chance of inhaling it, just stop.
If you get this far then I find the least effort is to now throw one of those dead cheap orange non-return hoses (cheap and cheerful and they just work) on and bleed from there. https://www.ebay.co.uk/itm/371718568796 ... R5ar15zNYg

[dern]

You can often clean enough of the pistons by pushing them out far enough for the clean bit to be exposed. If you do that you don't have to refill from scratch and you don't risk damaging the seals. The time this wasn't good enough usually meant the seals had gone and the result was that the pistons were corroded. We all do things differently though.

The non-return hoses are great... I've lost loads of them in the garage

[DefTrap]

I always split the calipers and take the seals out for a good old clean. I've tried the cheaty way but it just doesn't give the same level of satisfaction, and you can tell if you test the caliper without the pads in that some of the piston movement is still slightly compromised. But that's just me, I don't find the full strip that much harder or more time consuming.

[Noggin]

Have you already tried doing it the normal sort of way?

Nope. Haven't done anything yet!! Just thought I'd get some info before I got all brave and actually tried!! LOL

If you try to bleed that "normally" by pumping fluid from the reservoir through the caliper, gravity says the caliper body will drain of fluid and fill with air instead, so yes reverse bleeding is a good option. Or if you wanted to do it normally, take the caliper off the bike and keep it above the hose such that the bleed nipple is the highest point, while bleeding. Not as hard as it sounds if you have assistant. You may find it can be zip tied or even bolted to the exhaust hanger for that purpose, then you could do it without a helper.

Those caliers are pretty good quality, the pistons are aluminium so cannot rust. Even so it doesn't hurt to give it a spruce up while you're in there.

I doubt I can find a helper so was looking for an 'easy' way (relatively easy) to do this solo and figured that the reverse method with the syringe might be the easiest way?

Will go and have a proper look later and see if I can get the courage to actually do it!

That's not true as the pressure you're applying to the fluid through the lever pushes the fluid out and it can't be replaced by air if you close the bleed nipple while applying pressure. If you stop applying pressure and then close the nipple then there's a possibility that air can get in.

Solo and spazzy I might have issues!! Helper with two good hands and I might manage!!



The reason I want to try this is just because the rear brake is worse than shit!! And, despite everyone saying "they are all like that" I figure that whilst I wait on the insurance, I might as well make an attempt to see if I can make the brake a bit better to give me a little more confidence on the very downhill bit of any trip out!!

[A_morti]

If the brake isn't working well right now, just changing the fluid likely won't fix it. Take the caliper off and apart for a good clean, maybe a piston is dirty and bind up or there's corrosion or dirt in a seal groove behind the seal pushing it against the piston and stopping it all moving nicely.

You may also have got chain lube on the disc and/or pads. I had that on the front of my FZ, and the brake hardly worked. A good scrub with dish soap and a stiff brush got a lot of dirt off the pads and the disc, and after that it worked fine again.

Anything with a Brembo rear brake from the era has potential to be shit due to undersize caliper/oversize master cylinder, meaning it bleeds up firm, but takes an elephant standing on it to get much pressure built up. If that's the case on yours, only parts swapping will fix it. Maybe the bike-specific forums/groups know which parts are good?

[Noggin]

If the brake isn't working well right now, just changing the fluid likely won't fix it. Take the caliper off and apart for a good clean, maybe a piston is dirty and bind up or there's corrosion or dirt in a seal groove behind the seal pushing it against the piston and stopping it all moving nicely.

You may also have got chain lube on the disc and/or pads. I had that on the front of my FZ, and the brake hardly worked. A good scrub with dish soap and a stiff brush got a lot of dirt off the pads and the disc, and after that it worked fine again.

Anything with a Brembo rear brake from the era has potential to be shit due to undersize caliper/oversize master cylinder, meaning it bleeds up firm, but takes an elephant standing on it to get much pressure built up. If that's the case on yours, only parts swapping will fix it. Maybe the bike-specific forums/groups know which parts are good?

I could get it to think about working by pumping it for the first few kms, but it was never particularly 'good' - to the point that I wouldn't ride it to the valley if it was raining as I didn't have enough rear brake to feel comfortable riding downhill!! (Well, downmountain!) - Everything else about it I would be fine, but wet mountain road and very little to zero rear brake was not confidence inducing!!

Maybe I should leave it and just look to change it when I have it french registered and can afford to look for an upgraded system!!


I've never had a bike with bad brakes! And this isn't the oldest I've had!! But apparently the Monster rear brake is just bad I was just hoping that bleeding it would help. But maybe not

[dern]

Solo and spazzy I might have issues!! Helper with two good hands and I might manage!!



The reason I want to try this is just because the rear brake is worse than shit!! And, despite everyone saying "they are all like that" I figure that whilst I wait on the insurance, I might as well make an attempt to see if I can make the brake a bit better to give me a little more confidence on the very downhill bit of any trip out!!

The great thing about a bike is that you can reach the caliper and the lever at the same time, it's way easier than a car without a helper.

I'd definitely encourage you to make sure that your brake system is serviced and as good as it could be but some rear brakes are just shit. It's not helped by the rear not being used as much so the pad surface doesn't get routinely cleared. A good service and some new pads would definitely be worthwhile.

One thing that hasn't been mentioned I don't think is that the rear is often a single piston with the caliper sliding on a pin. If this sliding mechanism doesn't work then they will always be bad. I'd definitely recommend that you ensure that the sliding mechanism is working, not corroded and well lubricated.

[weeksy]

First things first, this is what this model of Ducati and setup are known for, same as some of the older Aprilias.... It's just how it is... you'll get it better, for a week...

[Noggin]

First things first, this is what this model of Ducati and setup are known for, same as some of the older Aprilias.... It's just how it is... you'll get it better, for a week...

I did think as I wrote the original post that this had been said (I don't have a lot of memory of a lot of things for the last three years, so sometimes struggle to remember what I've been told or if I've imagined stuff!!)

It was no different when it came back to me and I KNOW that it was serviced then! I just wondered if it was worth me doing the bleeding thing just in case it might help?!

The great thing about a bike is that you can reach the caliper and the lever at the same time, it's way easier than a car without a helper.

Unfortunately, I can't!! Definitely not on the right side of the bike as its the right arm that doesn't work, so I can't reach the two at the same time (Could have once, but not now )

Could do the front brakes, but not the rear!!

[Cousin Jack]

Advice on brakes. Sorry none as I've the mechanical ability of a mentally challenged hamster

Advice for Noggin. Call an ambulance for standby as you're bound to end up with the bike on your head or something

Good advice, which should be printed on a placard, because I need one too! Take it to a professional.