Topic: 750F front brake adjustment

[yhwu]

('76 750F) I'm wondering how tight the front caliper mounting bolts should be (the two 14mm ones). I'm adjusting the front brakes to get that 5-6 thou gap between the pad and the rotor, but there seems to be no way of getting a gap if both the 14mm are tightened, it just clamps both A and B pads to the rotor, making the adjustment screw also useless. It rubs me the wrong way having only those bolts on slightly more than finger tight...any input is appreciated!

[bryanj]

That means something is wrong as the bolts need to be tight

[BenelliSEI]

The two caliper halves must be tight together. The two pads are the “fixed pad” and the pad that is being pushed out by the piston in the caliper body. You then adjust the entire caliper (with the adjusting screw that passes through the tab on the fork leg) so the gap is between the “fixed pad” and the disc. The caliper is mounted to a bracket that must be able to swing freely on the fork leg. Make sure the swivel pin is clean and lubricated.

[HondaMan]

Check on the back side of the stationary puck (inner one) to make sure it is clean behind it, and the puck can wobble and float a little bit. This side aligns the caliper when the brake is pulled. I have sometimes had aftermarket pucks that had too much paint around their edges, or even on their back sides, which froze them stiffly in the stationary puck side, making it impossible to then adjust the brake for any clearance at all. If there is paint around the edges, file it off: if there is too much paint on the back side,sand it off of the middle dimple so it meets the stationary caliper metal-to-metal. This will help it self-align and float a bit.

[MauiK3]

My experience with them that the pucks and the bores have to be very clean or it won’t work right.

[Don R]

If it hasn't had a new piston seal recently, replace it and be sure the caliper seal's groove is surgically clean. The piston seal is square cut, it bends sideways under pressure and is what retracts the piston. The F0/1 has its own seal size too, slightly bigger than a K0-6. Same as an A or a K7-8

[yhwu]

Gotcha, thanks guys! I'll clean it again and hopefully that's my issue there.

[bryanj]

I think the 750 F has a different diameter piston to the early 750/500  but not 100% sure

[WhyNot2]

I just rebuilt mine and even changed to stainless steel lines, and it still wants to slowly lock up me.

[bryanj]

Did you clean every last bit of crap out of the seal groove with a dental pick? It needs to be perfectly clean!

2 other possibilities for slowly locking

1 tiny hole in master cyl bore blocked

2 colapsing flexibles

[BenelliSEI]

Did you clean every last bit of crap out of the seal groove with a dental pick? It needs to be perfectly clean!

2 other possibilities for slowly locking

1 tiny hole in master cyl bore blocked

2 colapsing flexibles

Exactly what he said.

[WhyNot2]

Yea, got it

And yes.

Will check the master again.

[bryanj]

Was one thing i forgot, is the pivot pin super free?