Empi disc brakes

[starrider1946]

I put a Empi disc brake kit on my trike. I mounted the calipers on the top. I am have great brakes. A whole lot better than the drums. I am well satisfied with that part but I get a noise when I use the brakes a certain way. I don't know exactly how to describe it. It is not a squeak. Sometime it makes it when I have my foot on the pedal and I am almost stopped. Has anyone else had trouble with the Empi kit. I know the rotors aren't perfectly true. Any suggestions?

 

[rhino 2]

I put a Empi disc brake kit on my trike. I mounted the calipers on the top. I am have great brakes. A whole lot better than the drums. I am well satisfied with that part but I get a noise when I use the brakes a certain way. I don't know exactly how to describe it. It is not a squeak. Sometime it makes it when I have my foot on the pedal and I am almost stopped. Has anyone else had trouble with the Empi kit. I know the rotors aren't perfectly true. Any suggestions?

If the rotors aren't true.....The pads might have to ware/set in a little......:Shrug:

 

[Jack Klarich]

If the rotors aren't true.....The pads might have to ware/set in a little......:Shrug:

If the rotors are not true the pads will move (rocking on the high spots of the rotor)

This can make a slight knocking sound or a swishing sound

 

[starrider1946]

I wish I could describe better what the brakes are doing. I am going to pull the wheels off tomorrow to get a good close look and see if I see anything out of the ordinary. I will post tomorrow.

 

[DeathBySnuSnu]

Ya know.....I think mine might have made the same sound since it has been back together.

Not all the time...but a couple times mine has made a chattering squeal sound almost like a high pitched gronk. Not loud or scary. Right before full stop. I do not think it has made it recently though. I just thought it was that I mixed up the used brake pads after it being apart so long and it has worn in now.

Maybe....the stamped empi caliper mounts are not perfectly parallel with the rotor. Sorta twisted an ever so small amount. And the pads are not perfectly flat on the rotors....yet, they will wear in.

 

[LarryA]

Ok guys I can't give a solution, but can add to the confusion.....question I have is........could the mounting angle of the caliper have a bearing on your problem? Kinda like the tool bit on a lathe being over or under center? or rake angle of the tool bit causing chatter? the caliper twisting forward or rearward or sideways during the application, then loses the grip from a movement of the disc or the caliper, the cycle repeating itself.

 

[Sidecarbill]

If the brakes work well and there are no unusual wear patterns, and everything is tight, and there is no indication of metal to metal wear anywhere. Then just drive it. Or is it a noise that turns peoples heads when you pull up. If it is then sell it to a harley rider they love it when you look at them.:laugh:

 

[starrider1946]

Fixing to go pull the wheels and take a look. They say to center the calipers on the rotor. If the rotor isn't perfectly true how do you center the caliper. Also how could you tell if the rotor is twisted. I will take a look and post later. Thanks for the comments.

 

[starrider1946]

empi disc brakes

Well I pulled the left wheel off this morning. I put my indicator on the rotor. I have .009 run out. Actually less than I thought. I measured from the the caliper to the rotor on the front of the caliper and the rear of the caliper on the outside part. It is within .010 of being the same so I would say it is square as I can get it. The center of the caliper looks to me like it centers to the center of the rotor. I can't really tell anything about any kind of wear pattern. The pattern on the rotor looks about the same on the inside and outside. I don't really see anything. I cleaned it real good with brake cleaner. I will probably check the other side tomorrow.

Oh! Sometimes it is loud enough to turn peoples head but I don't want to sell it. lol I may take it to a brake shop here in town and let them listen to it and see if they can tell me anything. They are real nice to deal with. They made some new springs for my rat rod.

 

[Jack Klarich]

Measure your rotors for thickness in 6 equal spots, IMO .009 is a lot of runout if the inside hat area of the rotor and the face of the bearing are clean of debris

I like to see .001-.003 run out, any more and I replace rotors, or clean the mating surfaces and re in dex them and get a new reading JMO

 

[starrider1946]

empi disc brakes

I will measure them in the six places tomorrow and see what I have. I actually thought .009 wasn't bad but I don't know much about disc brakes. What do you mean by re index . I don't guess it would have anything to do with having the calipers mounted on top of the axle. One of my friends has the same set up with calipers mounted on top and doesn't have any trouble. I don't know.

 

[Jack Klarich]

I will measure them in the six places tomorrow and see what I have. I actually thought .009 wasn't bad but I don't know much about disc brakes. What do you mean by re index . I don't guess it would have anything to do with having the calipers mounted on top of the axle. One of my friends has the same set up with calipers mounted on top and doesn't have any trouble. I don't know.

When I say index, mark on the rotor and 1 stud, that is your starting point for indexing

Some call it match marking

It is important with rotating mass like a rotor to put it back on the same as you took it off

If you mark it and want to move it you will know your original starting point

Once you mark it move it one stud hole, install the lug nuts and tighten by hand, re measure your run out and compare readings

You can keep doing this if you want to see if the run out changes, some times it does

As far as run out, if I see more than .003 I would replace rather than take a chance at trying to machine it

You can compound the run out very easy if you are not careful

The run out can come back to rear its ugly head again

There is a lot more than replacing pads and rotors involved in a quality brake service, unfortunately we all get in a hurry and take short cuts JMO

 

[starrider1946]

empi disc brakes

How can I check to see if the calipers are square to the rotor. I used the stamped brackets that came with the Empi kit. The calipers look centered to me. I wonder if I should take the calipers off and lightly sand them. The pads seem to touch the rotor all the time. I can roll the wheel over with no resistance. I did ride today and I put on the brakes kind of hard at about 35 and it did make the noise then. Could be described as a grabbing type noise. What would be a good way to clean the pad. Also should the pins that hold the pads be greased a little. I don't guess mounting the calipers on top of the axle would make any difference or would it. Thanks for the comments and suggestions.

 

[Jack Klarich]

Clean and lube any moving parts

If the pins are rusty remove the rust first

You can lightly sand the pads, you can also chamfer both ends of the pads, this will help the brake dust to fall off

Piggy back calipers have been around for a while, in MOST apps they work pretty good

Do NOT use brake cleaner on brake parts, try soapy water followed by a good rinse

Keep in mind most all disc brakes run with ZERO clearance between pads and rotors, that is( 1 of ) the jobs of the square cut O ring in the calipers

 

[starrider1946]

empi disc brakes

Jack I am just afraid I am not going to get the .001 or .002 thousandths run out with these Empi rotors. I read that if the rotors are warped I would get a pulsating pedal but i don't have that. I may try the cleaning and chamfer the pads and lubricate the pins which I didn't. They are new so they aren't rusty but they are dry. I wish I could tell if the noise is coming from both sides or just one side. I may also take the mounting bracket off and make sure it is good and clean behind it.

Can I take the rotor and have them turned? I don't know . I may have to try that also if everything else doesn't work. I may also have to order the cast bracket. They would probably be better. I want to make this work because I have much better brakes. Thanks Jack.

 

[Jack Klarich]

John, when you did your run out test did you have lug nuts back on and rotor torqued ?

This will make a HUGE difference, You can also remove the caliper and do your run out with no pads or caliper hook up, this will give you a base line to tell if your caliper is square to the rotor ( do a before and after reading with a dial indicator)

Brakes are not very complicated systems, They are VERY resistant to minor changes ( IE) poor castings ( rotors and calipers), low grade pads and hardware, dirt and grease are bad Ju Ju

Stick with it you will get it

 

[starrider1946]

empi disc brakes

No I just pulled the wheel off and checked the run out with the caliper still on the rotor. Maybe when I take the calipers off I will check the run out again. Didn't realize the difference it would make.

That may be why Empi sells the cast mounting bracket. They know the stamped one isn't good. I wonder if I should go ahead and order a set and put them on while I have the calipers off. I think they are around 80.00 dollars or so. I am going to check. Thanks again.

 

[Jack Klarich]

No I just pulled the wheel off and checked the run out with the caliper still on the rotor. Maybe when I take the calipers off I will check the run out again. Didn't realize the difference it would make.

That may be why Empi sells the cast mounting bracket. They know the stamped one isn't good. I wonder if I should go ahead and order a set and put them on while I have the calipers off. I think they are around 80.00 dollars or so. I am going to check. Thanks again.

After you re do the run out you may find the run out is NOT a problem

The mounting bracket surely could cause a binding brake and noise

I hope you get it figured out

I will check back to see if I can help you some more

I think you have a good approach now