Grabbing brake.

Sporty talk! email JCC UK and JOAC Registrar. Technical Question? Try Service Bulletins or TechNotes or Tech Library first. Note that you need to be a club member to view the Tech Library.. Parts book
Thanks to those who voted for the Jowett Jupiter as Practical Classic's Car of the Year 2010. Read the saga of why the SC deserved to win on JowettTalk-Great SC rebuild or Amy's call to action.
Post Reply
Forumadmin
Site Admin
Posts: 20648
Joined: Tue Feb 07, 2006 5:18 pm
Your interest in the forum: Not a lot!
Given Name: Forum

Grabbing brake.

Post by Forumadmin »

I am investigating uneven emergency stopping with one wheel skidding on a dry road. Could this be the issue and what is the cure?
Front right (offside) upper shoe not wearing evenly.
Note the lower shoe is evenly wearing but the upper shoe seems twisted and not the normal issue with a worn back plate dimple causing the outside of the shoe to wear more than the inside. Here the area not wearing is on the outside on the leading edge and on the inside on the trailing.
20240831_164246.jpg
20240831_164253.jpg
20240831_164300.jpg
20240831_164308.jpg
20240831_164405.jpg
You do not have the required permissions to view the files attached to this post.
Forumadmin
Site Admin
Posts: 20648
Joined: Tue Feb 07, 2006 5:18 pm
Your interest in the forum: Not a lot!
Given Name: Forum

Re: Grabbing brake.

Post by Forumadmin »

Note the wear on the lower shoe shows the diameter of the drum is slightly larger than that of the shoe since it is not wearing on the leading and trailing edges.The braking efficiency was probably less when the shoes were initially installed but improved as they bedded in.

I am also checking the rear brakes as the locking wheel was on the other side to this shoe.
Keith Clements
websitedesign
Posts: 3968
Joined: Wed Feb 08, 2006 11:22 am
Your interest in the forum: Jup NKD 258, the most widely travelled , raced and rallied Jowett.
Given Name: Keith
Contact:

Re: Grabbing brake.

Post by Keith Clements »

The rear shoes also had some uneven wear. Surprisingly the dimple adjustments done years ago seem to have changed or were the new shoes different?

Anyhow apart from that things seemed fine so for now everything was put back. When these shoes have worn out I will readjust since they should now be bedded in.
20240902_095906.jpg
20240902_095915.jpg
20240902_095923.jpg
20240902_103606.jpg
20240902_103616.jpg
20240902_103625.jpg
You do not have the required permissions to view the files attached to this post.
skype = keithaclements ;
David Morris
Posts: 837
Joined: Thu Feb 09, 2006 9:23 am
Your interest in the forum: Jowett Javelins since 1964. Now a Jowett Stationary engine owner and club member since 1964.
Given Name: David
Location: Sunny Bristol

Re: Grabbing brake.

Post by David Morris »

Hi Keith,

With reference to the grabbing brakes, have you tried swapping the drums from side to side, to see if the grabbing problem follows the drum to the other side?

I would suspect that the drums may have worn unevenly and no longer be round, but slightly oval? On the US revival videos that I often watch, their autoparts stores all across the country have a refinishing service in-store for the drums or discs ( they call them 'rotors' over there! ) to restore a perfectly 'true' surface. If you have access to a large enough lathe, perhaps you can do this yourself? I know that the US parts stores have this special rig that is designed to solely do the service that I have mentioned.

All the best,

David
Keith Clements
websitedesign
Posts: 3968
Joined: Wed Feb 08, 2006 11:22 am
Your interest in the forum: Jup NKD 258, the most widely travelled , raced and rallied Jowett.
Given Name: Keith
Contact:

Re: Grabbing brake.

Post by Keith Clements »

No David I have not swapped, mainly because the shoes have not yet bedded in. I thought it might be because of incorrect fitting so will let them settle down some more.
These drums have been skimmed on my lathe so that could be the problem!
skype = keithaclements ;
Post Reply

Return to “Jupiter”