Rear Brake
8 posts
• Page 1 of 1
Rear Brake
Hi, I recently bought a AJS Tempest Scrambler having had several motorcycle over the years but now that I have reached 71 years old I need something nice and light and this motorcycle is great, but have a slight problem with the Rear Brake,the rear brake pedal moves a long way down before it activates the back brake, I have adjusted the brake rod slightly which moves the brake pedal slightly lower but it still goes down a long way before the back brake will work, any help on this would be greatly appreciated .
- spookefoote1956
- Member
-
- Posts: 875
- Joined: Mon May 01, 2017 6:32 pm
- Location: Lancashire
Re: Rear Brake
Hello Nigel. If I'm right that bike is disc front and rear? Or is it drum back?
Put the bike on the centre stand, adjust the rod (if that's what it is) whilst turning the back wheel. When it starts to grab back it off a bit and you should be ok. However still let me know if it's disc or drum. If possible upload a piccy as that will help.
Cheers, Chris
Put the bike on the centre stand, adjust the rod (if that's what it is) whilst turning the back wheel. When it starts to grab back it off a bit and you should be ok. However still let me know if it's disc or drum. If possible upload a piccy as that will help.
Cheers, Chris

हरे कृष्ण हरे कृष्ण
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
Re: Rear Brake
Hi
It sounds like the rear system either needs bleeding or the addition of more fluid followed by bleeding, - have a good look at the whole combined system to ensure it's not leaking fluid.
Regards Mick
It sounds like the rear system either needs bleeding or the addition of more fluid followed by bleeding, - have a good look at the whole combined system to ensure it's not leaking fluid.
Regards Mick
Re: Rear Brake
Hi Nigel. That's very interesting as I have the same issue with my 'Mutchless' (My Chinese Herald 250 Classic. Engine based upon the 250cc Suzuki GN 250).
When operating the rear brake the pedal travel 'slack' is excessive and my toes are damn near pointing at the ground before the pads contact the disc. It seems as though the pads are retracting too far back into the caliper.
This is a G.A. of the slave cylinder location....
In the photo below you will see that the threaded adjuster 'A' is fully extended so no further adjustment is possible. I had considered making a longer threaded adjuster but it appears to be an integral part of the piston inside the cylinder even though the locknuts at its rubber boot end suggest otherwise. I am intending to experiment by making a deeper (longer) clevis 'C' which connects the pedal arm to the threaded adjuster in order to take up the slack.
The dealer from whom I bought it 3 years ago suggested the following causes, none of which apply to my brake........
Low Hydraulic fluid level.
Hydraulics need to be bled.
Brake pads worn.
Disc distorted (pushing the pads back further into the caliper).
Brake pedal arm bent.
Wear in clevis pin.
When operating the rear brake the pedal travel 'slack' is excessive and my toes are damn near pointing at the ground before the pads contact the disc. It seems as though the pads are retracting too far back into the caliper.
This is a G.A. of the slave cylinder location....
In the photo below you will see that the threaded adjuster 'A' is fully extended so no further adjustment is possible. I had considered making a longer threaded adjuster but it appears to be an integral part of the piston inside the cylinder even though the locknuts at its rubber boot end suggest otherwise. I am intending to experiment by making a deeper (longer) clevis 'C' which connects the pedal arm to the threaded adjuster in order to take up the slack.
The dealer from whom I bought it 3 years ago suggested the following causes, none of which apply to my brake........
Low Hydraulic fluid level.
Hydraulics need to be bled.
Brake pads worn.
Disc distorted (pushing the pads back further into the caliper).
Brake pedal arm bent.
Wear in clevis pin.
You do not have the required permissions to view the files attached to this post.
I poke badgers with spoons.
Re: Rear Brake
Neville , I assume both bikes have combined braking where there is a bias to stop the rear brake locking up
if you apply the front brake and then the rear brake does the foot brake go so far down ?
if you apply the front brake and then the rear brake does the foot brake go so far down ?
Re: Rear Brake
g80csp11 wrote:Neville , I assume both bikes have combined braking ........
No, mine's two independent systems but I believe the Ajay's are combined.
I poke badgers with spoons.
Re: Rear Brake
Hi
The 'mechanism' that retracts the pads from the disc is usually the design of the calliper to piston seal(s), when the brake pressure is released the pads should withdraw from the disc by a few thou, (say two to three typically).
Without moving your bike apply the rear brake firmly for a few seconds then release it and measure the pad to disc clearances with feeler gauges, then spin the rear wheel a couple of times and re-measure the clearances.
If the first set of measurements are significantly larger than three thou or significantly different from side to side, (if the calliper is a twin piston one), the calliper seals are suspect.
If the second set of results are significantly larger than the first it suggests the disc is warped or not mounted on the same plane as the calliper.
Regards Mick
The 'mechanism' that retracts the pads from the disc is usually the design of the calliper to piston seal(s), when the brake pressure is released the pads should withdraw from the disc by a few thou, (say two to three typically).
Without moving your bike apply the rear brake firmly for a few seconds then release it and measure the pad to disc clearances with feeler gauges, then spin the rear wheel a couple of times and re-measure the clearances.
If the first set of measurements are significantly larger than three thou or significantly different from side to side, (if the calliper is a twin piston one), the calliper seals are suspect.
If the second set of results are significantly larger than the first it suggests the disc is warped or not mounted on the same plane as the calliper.
Regards Mick
Re: Rear Brake
Yes, my AJS has combined braking, so I will check what has been mentioned regarding the front brake.
8 posts
• Page 1 of 1
Who is online
Users browsing this forum: No registered users and 1 guest