Need help! Disc brake bolt rubbing on rotor!

It does have that one washer that you pound over to sort of lock the bolt.

Also, I forgot to mention that it does not drag when you spin the wheels with it jacked up. Only with weight on it. Of course I wouldn't have driven it if it did.

Don

D.S. said:

If there is a washer between the bolt head and bracket loose the washer for more clearance...
If that's not enough grind the head down a little... If more room is still needed countersink a flat head bolt into the bracket...

Click to expand...

So Dave, is this a normal problem when adding disc to stock spindles?


Don

You might want to check the preload on the wheel bearings, sounds like they might be a little too loose and lose the washer.
Bob

finallyhavea57 said:

It does have that one washer that you pound over to sort of lock the bolt.

Also, I forgot to mention that it does not drag when you spin the wheels with it jacked up. Only with weight on it. Of course I wouldn't have driven it if it did.

Don

Click to expand...

You could eliminate the washer with a little drop of #242 blue loc-tite then...

Must have been almost 0 clearance the bolt and rotor...
Were the bearings loose enough to allow the rotor to wobble?

Rotor did not wobble with hand pressure and I don't think it wobbled with the wheel on. I will make sure of that when I try your solutions.

Don

57viper said:

You might want to check the preload on the wheel bearings, sounds like they might be a little too loose and lose the washer.
Bob

Click to expand...

I will get rid of the washer Bob and also maybe grind a little of the bolt off. Guess I should do the same to the driver's side even though it's not rubbing now.

Don

My CPP disk setup had a really close top bolts. All I did was slowly grind the bolt heads down a bit to add extra clearance.

Thanks guys! I removed the washers on both sides and ground the head of the bolt on my passenger side down. The bolt on the driver's side was OK because my kit was missing that one and I local purchased one and it's head was shallower.

Now I need to take it to a tire place and have the front end aligned and will also have them turn that rotor. As it turns out I have a broken stud on that rotor I need replaced so they will do that as well.

Don

Brakes

Don, I have the same type brake set up mine does not have a washer and I add some lock tight to the top bolt it was the blue lock tight so you can remove it if you need to. If its hiting when its on the ground the bearings are not preload and the wheel is loose, with it jack up see if you can tilt the tire up and down , if the other side does not rub then its in the rotor loose check it. Later Bill

Hmmmmm, Interesting, but

keith said:

My CPP disk setup had a really close top bolts. All I did was slowly grind the bolt heads down a bit to add extra clearance.

Click to expand...

consider this; the fastener is designed to hold (clamp) the brkt. to the spindle. This design requires a certain torque value. That value is applied to the underside of the bolt head continuously. Lessening the thickness may decrease the clamping force or weaken the fastener and failure occur.

I would rather consider the Flat Head idea. After all, several of the Wilwood designs are done this way so it clears.

JFFT,

Nick

finallyhavea57 said:

Now I need to take it to a tire place and have the front end aligned and will also have them turn that rotor. As it turns out I have a broken stud on that rotor I need replaced so they will do that as well.

Don

Click to expand...

Tell them minimal cuts on the rotor,,just until it cleans up. The thicker the rotor, the better.

I have cut really expensive/rare rotors that were throw-away as per the minimal thickness, just cleaned the surfaces up better and removed the heavy grooves and made the customer/friend aware to be easy on the brake pedal. he ran another 30K out of them without problem and they were way under minimal.

Well it for sure has clearance between the bold head and the rotor now. I didn't take much off the one head. For that matter, the head on the driver's side was the same thickness as the passenger after I ground it a little. I think all is good now and will be better after I get it to an alignment shop.

The temp is in the 90's now so I'm not working outside anymore today. Have a funeral to go to tomorrow and then about three days to do some work on my 57' 210 waiting in the wings. I will update that in a later post on the 210.

Thanks again for the advice.

Don

Glad you got it fixed Don :congrats:

"This design requires a certain torque value. That value is applied to the underside of the bolt head continuously. Lessening the thickness may decrease the clamping force or weaken the fastener and failure occur.

I would rather consider the Flat Head idea. After all, several of the Wilwood designs are done this way so it clears."

I don't buy into this for two reasons. First, if the bolt hole is not oversized, how is the bolt head going to bend or deflect any differently than a thick headed bolt?

Second, have you studied a flat head bolt's head dimensions? Not too different from a cut down hex head.

The reason they make bolt heads as tall as they do is to keep wrenches and sockets from slipping when you apply the torque needed. If you use a six point socket or box wrench on a cut down bolt head you'll be OK.

Sure enough though, you could cut one down too much.

I didn't see that you added the Blue Loc-tite. Since you removed the locking washer be sure to add the blue loc-tite (NOT RED). Blue will allow you to take it off if ever necesary will still allowing it to not come loose from Vibration. Just a saftey precaution!!

Glad to hear you got that fixed. Were you able to save the rotor?

I think this is a place to use the red Loctite.

It is much less "permanent" than many of you think.