seizing front brake

Check the new and old levers against each other then file the new one to match.
Or put the old lever back.

 

check the free play of the new lever as you pull it on with light pressure. It should be almost 20 mm at it's extreme if it's as long as the original with a 'ball' on it's end.

 

To be honest, i've seen nothing but hassle with pattern levers. I know of two that have resulted in accidents. I won't fit them let alone supply them. As mentioned above, check the free play in the assembly before the pushrod touches the piston in the master cylinder, you may be able to adjust it out. The later type levers with the barrel, the ones i've seen, haven't even been close to being able to work though as the hole centres were all wrong. The earlier type lever need usually need filing.
I know the OEM stuff is expensive, but tbh the brakes aren't something to skimp on. I'd fit a genuine part and be safe in your mind that it's going to work.

 

I suspect you have over adjusted it.
The inner part of the MC piston is covering the fluid return 'ole.

It's not about whether it's free now, it's whether it remains free when things warm up!
If the internal part of the MC is adjusted in too far past the return to the reservoir when the system/fluid warms up it will have no where to go other than squeeze the pistons together on yr disc and you will be off!
To check, remove one of yr calipers and gently squeeze the brake lever until a piston starts to move.
Then lever/push the piston back and see if the fluid level rises in the reservoir.

Seriously - check before you ride it.

 

+1 on wot Nelson says

 

talk about giving the bloke conflicting advice Nelson! - it's all about how much play when cold in this case unless by massive coincidence the calipers have decided to start seizing at exactly the same time the new lever has been fitted?.. had this started to happen 'totally out of the blue' then the answers would be a lot different.

 

Hardly "conflicting" . Clearly it's not a coincidence as the OP has said he has fitted new levers!
Advice remains the same, he fitted them and all seems well until the bike warms up.

Whatever....:biggrin:

 

The lever is causing the system to 'pump up' by not allowing the system to de pressurize when the lever is released and is causing the brakes to drag a little. After the mile or so, the disc and pads are that hot they start to drag. They WILL seize eventually. That's been the cause of the accidents I know of........

 

Again wot Nelly & Nelson say, the new leavers are not allowing the master cylinder to vent/pass fluid back up in to the reservoir hence the circuit is over presurising as the fluid heats up thus causing the brakes to drag and eventually seize

 

As Nelson says,
Its the fluid return hole. Had exactly the same problem after Pazzo levers were fitted, almost locked up when warm but luckily managed to keep it upright.
Turned the pushrod adjuster on the lever half a turn out and it was sorted. Simple, but effective!

 

except that it is (conflicting) - all wgrant needs to do is concentrate on the lever and adjustment - if it even has any yet your telling him to start removing calipers! and let's (despite losing the will to live here) look at the specific reason I replied in that manner again :-

well maybe I misunderstood you* but it looked like a direct response to my post where I recommended examining before use rather than after and my reason for this and additional response (apart from previously privately 'no sh*t sherlock!') would be :- A/ You just fitted the lever, so why wouldn't you? B/ It would prevent the likelyhood of an accident caused by either the return gallery being masked or the lever being forced to reach full abutment (and nobody knows which yet for sure) resulting in caliper(s) locking on, as you found out before you ventured down the road.(and so something that we all ought to agree on.) C/ If you decide to check for correct operation 'when things warm up' you would have no way of knowing for certain if it was due to the lever being adjusted incorrectly to start with or due to the calipers partially seizing all on their own, or a combination of both because there's (worse case scenario) no play to measure! (and a real 'doh!' moment.)

I sometimes feel that responses on here have more in common with 'Lord of the Flies' than several people methodically taking the time to appreciate each person's technical opinion so maybe as you say, the modern response 'Whatever' is probably more apt..

 

Its NOTHING to do with calipers seizing. If the calipers were seized, the pistons wouldnt move, hot or cold, as they would be seized. So, its quite obvious that they are moving, or the brake would not be being applied. SO, as Chris says, it would seem that the fluid is heating and expanding, and there is insufficient free movement of the piston ( probably caused by poor lever adjustment, as it was ok before changing the lever ) to allow correct flow of brake fluid.

 

Chris,

I think we're violently agreeing here.
Clearly checking the brake lever adjustment is valid as is removing a caliper to check for return to the MC.

Losing the will to live here also.... Have a super day and thanks for the ebay links to the battery leads and terminals. should see those today...

 

Have you dropped the bike on the brake lever side by any chance ?

brian.

 

'manga' had some good advice at the beginning - if you put old lever back on, does it cure the problem?..