Hi, I have a 1995 748. Looking for a bit of comparison advice on the free play movement on the front brake lever. The lever is the original factory fit Brembo lever, this type of lever doesn’t have a reach adjustment dial type thing. There is very little play in the lever before the brakes engage, just a few mm, I have a couple of other bikes and the movement before the brakes bite is around 10mm or so. What concerns me are the horror stories you hear about the lever not allowing the piston to return beyond the bleed hole and causing brake lock up when the fluid heats up. Ive only ridden the bike a couple of times and had no issues, but just wondered if a fellow member has a similar era bike and if their brake lever is the same, just for peace of mind. There’s no adjustment on the lever other than the grub screw/cup affair that the plunger sits in, this appears to be locked in place with an adhesive resin type stuff assuming at factory and I’m reluctant to mess with that. For me this small amount of free play makes the brakes a bit keen, but if that’s how they are then fine. Incidentally, the rear brake is similar with very little movement before the brakes engage. Any feedback much appreciated. Mark
No. If the screw is adjusted too far in the piston won't come right back so the bleed hole to the reservoir will remain covered. The fluid in the brake line will become pressurised when the brake gets hot, causing the brake to bind, generating more heat with the danger of the wheel locking up. If you want the lever closer to the bar before the bight point you could back it out a little but be very careful if turning the screw further in.
@Derek - are you sure you have that the right way around? If I remember correctly, one would screw the grub screw in to get more free play before engaging the piston. Apologies if My memory is incorrect, it was 20 years ago!
Absolutely sure. The pushrod engages into the recess in the screw with its other end bearing against the piston.
As Derek says, if you tighten the grub screw in it will push the plunger tighter, it will need slightly undoing if anything.
Thanks very much for the input so far. I agree totally on the grub screw, screwing it in would push the plunger in and prevent fluid returning which would cause the brakes to lock on their own, something I’m not going to do. The issue I have is that there is very little free play in the lever before the brakes take up and I just wondered if this was as it is on early 748. I’m not concerned about the lever reach etc. I could adjust the grub screw out but as it is sealed in position by the looks of it at factory I was reluctant to do that without seeing if that’s the way they are set up.
Can appreciate what you are saying, ideally you could do with a quality aftermarket lever with an adjustment facility, something which I’m not sure is available on that early lever. Overall it’s better to have it this way then the opposite! Is it a very low mileage bike with brand-new brake pads? The latter doesn’t always help in this situation.
Yes it is Chris. It’s a ‘95 bike with only 8500miles, pads have only done 500 miles. The movement before the lever begins to feel firm is around 3mm. The rear brake lever is similar although that is slightly deceiving as the early models don’t have a return spring so in actual fact the movement (free play) there is more. I’m comparing it to the levers on my other bikes, Street Triple, ZXR400 and Aprilia RS, they all have free play of around 10mm, that you take up before you squeeze on the brakes if that makes sense. Maybe I’m over thinking it, but just concerned about the fluid return lock-up thing, that I once experienced on a bike after fitting a non OEM lever, was a bit scary. All levers on the 748 are factory Brembo.
You need a bit of free play in the rear brake lever, they are well known for sticking on as they warm up if adjusted with no slack. Steve
agree with Steve above and was going to add, don't be fooled by the amount of std play on rear pushrod as it's almost a given that a large engined post '90's Ducati rear brake will suffer with heatsoak dissipating into rear brake lines. If weather constantly hot/using in traffic then sometimes standard play needs to be exceeded. I've travelled with 10mm/8mm open ended spanners before as a precaution.
Sorry, My memory was completely cock - I thought the screw head was from the other direction. Doh. Apologies.
If I understand correctly you aren't really talking about freeplay but rather the amount of travel that is required before the brakes bite. That is determined by the lever ratio and the master cylinder piston size. If you want to increase the amount of travel on your lever you need either a adjustable ratio level like the later ones with the dial adjuster or a master cylinder with a smaller piston. As long as you have some play between the master cylinder pushrod/piston and the grubscrew that pushes on it you won't have binding of the brakes. I would set the play to about 1mm.
Just measured my front brake lever travel, from the end of the lever to the center of the bar end plug is 125mm brake fully pulled back 95mm, this is with the bike stood, obviously the brakes will start to be applied before the lever is fully applied, hope this helps. Steve
