Slack adjusters on hydraulic brakes

[Simmy]

Just thinking here... surely slack adjusters are no good on hydraulic only brakes? Or am I just been stupid. Air would only shove it to the brakes were on. Were as hydraulic will shove past till the ram is fully extended....

 

[davidroberts30]

both systems will only push until the brakes are applied

 

[Pheasant Surprise]

Just thinking here... surely slack adjusters are no good on hydraulic only brakes? Or am I just been stupid. Air would only shove it to the brakes were on. Were as hydraulic will shove past till the ram is fully extended....

Not sure I really follow the OP. Is there a question there?

The purpose of the slack adjuster is to allow adjustment in the brake linkage to compensate for wear in the shoe and drum.

If you didn’t have a slack adjuster, then with wear of the friction material you wouldn’t be able to either manually (or automatically) take the excess “slack” out of the actuation so that (a) the shoes don’t bite too late when brakes are being applied and (b) as the friction material wears, to ensure that maximum brake effect is applied, such that the lever doesn’t go way over centre at full stroke - this reduces the power onto the s-cam from the cylinder and hence your braking power.

 

[Andrew]

Just thinking here... surely slack adjusters are no good on hydraulic only brakes? Or am I just been stupid. Air would only shove it to the brakes were on. Were as hydraulic will shove past till the ram is fully extended....

So what happens if the hydraulic ram reaches the end of it’s travel before the brakes are applied? That’s why you need the alack adjusters.

 

[davidroberts30]

So what happens if the hydraulic ram reaches the end of it’s travel before the brakes are applied? That’s why you need the alack adjusters.

Same with air piston