2 replies to this topic

[v6 torana]

Has anyone ever come across a HZ Girlock Alloy Front Brake Caliper with a machined surface that the caliper piston seats on as wide as the one in the first picture ? I have been chasing a front brake pull problem and found that the caliper piston in this caliper was seating on the centre dimple therefore sitting several mm higher that the opposite caliper piston. The second picture has a normal seat width.

 

Any thoughts ?

 

 

 IMG_9064.JPG   137.56K   5 downloads

 

 IMG_9063.JPG   208.05K   5 downloads

 

 

[Bigfella237]

It shouldn't make any difference, the only time the piston would go in that far is when you push it all the way back for a pad change.

 

Unless you've got some MAJOR knock-off problems that is, but if it were that bad you'd need to pump the pedal three times for every brake application!

 

It would change the volume of fluid behind the piston slightly (compared to the other caliper) but not the piston's surface area so (assuming the pistons in both calipers are the same diameter) it shouldn't affect the pressure exerted on the brake pad from one side to the other.

[76lxhatch]

I would tend to agree that it doesn't matter (as long as the piston is able to retract far enough to avoid dragging). I had a pair of these recently that had to be binned, the pedal was mushy to the point of being ridiculous and the only conclusion was that the calipers were old and flexing, resolved by replacing them with a more rigid caliper. The different machining might suggest that you have a mixed pair so one could be worse than the other?