Front Caliper Problem

[djg42]

Hello,
I just took off my front wheel and forks. I put everything back on and now my front wheel isn't spinning freely. If the 2 bolts which hold the caliper on are loosened to the point i can turn them with my fingers, the wheel spins freely, but once i tighten the bolts there is no free spin. Other than that, the brakes seem to work fine.
What happened? How do I correct this?
THANKS!
DG

 

[Nessism]

Unless you have already done it I'd remove the caliper and pull the piston out to clean all the grunge out from inside the caliper. Brake fluid is hydroscopic which means it holds water, and old brake fluid jells up and coagulates with age so the best thing to do is make sure the system is properly cleaned out from time to time. Also, replace your rubber brake line if you still have the original. Suzuki calls for periodic line replacement so if your bike has the original you are about 28 years overdue.

 

[almarconi]

If the 2 bolts which hold the caliper on are loosened to the point i can turn them with my fingers, the wheel spins freely, but once i tighten the bolts there is no free spin. Other than that, the brakes seem to work fine.
What happened? How do I correct this?

You tightened the bolts too much. Put a couple of drops blue loctite on the bolts and snug them up. You know your too tight if the wheel will not spin freely. Don't worry, the caliper will not fall off. Make sure the caliper pins are lubricated with a good quality moly brake grease.

 

[Nessism]

You tightened the bolts too much. Put a couple of drops blue loctite on the bolts and snug them up. You know your too tight if the wheel will not spin freely. Don't worry, the caliper will not fall off. Make sure the caliper pins are lubricated with a good quality moly brake grease.

I don't understand this advice. Please explain. How are the caliper bolts causing the caliper to bind.

 

[almarconi]

Ed..if the caliper bolts are too tight the wheel will not spin freely. Go out in your garage, jack up the front wheel on one of your bikes and over tighten the two caliper bolts. Your wheel will not spin. I have no scientific reason other than "been there, done that".

 

[Nessism]

Ed..if the caliper bolts are too tight the wheel will not spin freely. Go out in your garage, jack up the front wheel on one of your bikes and over tighten the two caliper bolts. Your wheel will not spin. I have no scientific reason other than "been there, done that".

Al, the caliper hanger is the part that's bolted to the fork, and the main caliper body floats on the sliding pins and adjusts to the disc. I don't see how over tightening the hanger bolts could have any effect other than maybe causing them to strip out; the hanger abuts with the lugs on the fork in an uncompressable interface. Most likely the situation you have experienced relates to tweeking the fork sliders when the hanger bolts are tightened, a situation that will clear its self up once you move the bike around and compress the suspension a few times.

 

[bwringer]

Al, the caliper hanger is the part that's bolted to the fork, and the main caliper body floats on the sliding pins and adjusts to the disc. I don't see how over tightening the hanger bolts could have any effect other than maybe causing them to strip out; the hanger abuts with the lugs on the fork in an uncompressable interface. Most likely the situation you have experienced relates to tweeking the fork sliders when the hanger bolts are tightened, a situation that will clear its self up once you move the bike around and compress the suspension a few times.

Agreed.

Loosening the caliper bolts and using Loctite is dangerous advice.

 

[madjack57754]

I'd check the simpelest thing first. Sounds to me like the brake is dragging. Hold the brake lever with light pressure and pop the bleeder screw loose, while maintaining pressure on the lever. Tighten the bleeder and pump up the brakes. If it is still not spinning freely there are other issues like a hung caliper

 

[jwhelan65]

Take Ed's advice on this one, tear down the calipers and make sure everything is cleaned and functioning properly. Trust me you will be glad you did this after you see what it looks like in there.

 

[almarconi]

Al, the caliper hanger is the part that's bolted to the fork, and the main caliper body floats on the sliding pins and adjusts to the disc. I don't see how over tightening the hanger bolts could have any effect other than maybe causing them to strip out; the hanger abuts with the lugs on the fork in an uncompressable interface

Ed, I'm not talking about the bolts that hold the caliper bracket to the fork leg. I have found that if the two bolts that hold the caliper to the bracket are overtightened the wheel will not turn freely.

Loosening the caliper bolts and using Loctite is dangerous advice.

The factory manual provides a torque spec for these bolts. If they are overtightened, the front wheel will not spin freely. It is quite acceptable to put a drop or two of blue loctite on these bolts. I am not in the habit of giving advice to people without giving my response to a question a reasonable amount of thought. If you read the initial post, the OP reiterated my observations. Advice given on a forum should be taken with a grain of salt since you are ultimately responsible for the safe operation and repair of your bike.

If the 2 bolts which hold the caliper on are loosened to the point i can turn them with my fingers, the wheel spins freely, but once i tighten the bolts there is no free spin.

I did not post this, the OP did. It is a true observation. Go to your garage, jack up the front wheel and over tighten the two bolts that hold the caliper to the bracket. Spin the wheel and see what happens.

 

[djg42]

Thanks everybody for your advice. The bolts that hold the caliper to the fork leg are the ones that when loosened allow my front wheel to spin freely. I didn't do any adjustment to the caliper itself. An interesting note though, the manual says to tighten the other 2 bolts on the caliper to only "finger tight".

Which bolts do you mean i should keep looser and use loktite on-the ones im talking about that hold the caliper to the forks?

Anyways, the fact is when the bolts that hold the caliper to the fork leg are tightened-the wheel wont spin freely.

 

[almarconi]

Thanks everybody for your advice. The bolts that hold the caliper to the fork leg are the ones that when loosened allow my front wheel to spin freely. I didn't do any adjustment to the caliper itself. An interesting note though, the manual says to tighten the other 2 bolts on the caliper to only "finger tight".

Which bolts do you mean i should keep looser and use loktite on-the ones im talking about that hold the caliper to the forks?

Anyways, the fact is when the bolts that hold the caliper to the fork leg are tightened-the wheel wont spin freely.

The bolts that I am referring to that I use a dab of locktite on are #12 in the diagram. I usually install them finger tight and snug with a wrench. On my bike, if these bolts are too tight, the wheel will not turn freely. To date, I have never had a caliper fall off by using this method.

From what you are describing, it sounds to me like you have the bracket #6 misaligned since it can only bolt to the fork leg one way.

Are your forks straight ?
Is the bracket mounting surface flush with the fork leg and/or is the bracket straight?
When the caliper is mounted, are the pads square to the brake rotor or cocked to one side?

In your original post when you said

If the 2 bolts which hold the caliper on...

I assumed you meant part #12, the two bolts that hold the caliper to the bracket and not part #16.

I hope that this clears up any confusion.

To bwringer - Rest assured it was not my intention to provide any advice that would in anyway have endangered anyones safety.

 

[Nessism]

The bolts that I am referring to that I use a dab of locktite on are #12 in the diagram. I usually install them finger tight and snug with a wrench. On my bike, if these bolts are too tight, the wheel will not turn freely. To date, I have never had a caliper fall off by using this method.

From what you are describing, it sounds to me like you have the bracket #6 misaligned since it can only bolt to the fork leg one way.

Are your forks straight ?
Is the bracket mounting surface flush with the fork leg and/or is the bracket straight?
When the caliper is mounted, are the pads square to the brake rotor or cocked to one side?

In your original post when you said


I assumed you meant part #12, the two bolts that hold the caliper to the bracket and not part #16.

I hope that this clears up any confusion.

To bwringer - Rest assured it was not my intention to provide any advice that would in anyway have endangered anyones safety.

Sounds like something is wrong with your calipers. Those small bolts screw into the slide pins, thus anchoring them to the caliper hanger. If there is misalignment when the screws are tightened something is either bent or the caliper hanger has been gouged out by the sliding pins thus allowing them to tilt.

One thing I've noticed about that type of sliding pin is they will rotate and bind against the caliper hanger. You want to make sure the flat in the pin is not touching the hanger - it may be necessary to use a screwdriver or wedge of some sort to shim between that flat and the hanger to keep it form turning.

If I were you I'd take a close look at those pins and hanger brackets to see if there is any reason those pins get out of parallel when tightening the bolts.

 

[tkent02]

If the calipers cannot slide freely on the pins this will happen. They need to be able to slide, or one side of the caliper cannot release completely after being applied. Take the pins out, clean off any rust or dirt and lubricate them well.
Locked front brakes are only funny when they happen on You Tube.

 

[almarconi]

Sounds like something is wrong with your calipers. Those small bolts screw into the slide pins, thus anchoring them to the caliper hanger. If there is misalignment when the screws are tightened something is either bent or the caliper hanger has been gouged out by the sliding pins thus allowing them to tilt.

One thing I've noticed about that type of sliding pin is they will rotate and bind against the caliper hanger. You want to make sure the flat in the pin is not touching the hanger - it may be necessary to use a screwdriver or wedge of some sort to shim between that flat and the hanger to keep it form turning.

If I were you I'd take a close look at those pins and hanger brackets to see if there is any reason those pins get out of parallel when tightening the bolts.

Ed..where you referring to the calipers on my GS750? My calipers/brakes work fine. Everything up front was rebuilt soon after I bought the bike. If I over tighten the caliper mounting bolts on my KZ 750 which has a similar setup the wheel will not turn freely. Maybe when the bolts are overtightened the caliper becomes cocked and binds up. Once the wheel is bound up, loosening the caliper bolts and spinning the wheel frees everything up.

 

[djg42]

Thanks, will I have to you bleed the brakes after i clean it out?

Unless you have already done it I'd remove the caliper and pull the piston out to clean all the grunge out from inside the caliper. Brake fluid is hydroscopic which means it holds water, and old brake fluid jells up and coagulates with age so the best thing to do is make sure the system is properly cleaned out from time to time. Also, replace your rubber brake line if you still have the original. Suzuki calls for periodic line replacement so if your bike has the original you are about 28 years overdue.

 

[almarconi]

Thanks, will I have to you bleed the brakes after i clean it out?

Yes you will.

 

[djg42]

now that im looking closer at the brakes, the front brake lever feels weird, i can pull it all the way to the handlebar without much effort, is this "spongy"? Does it mean theres air in the brake line? Thanks

 

[gggGary]

You have the advice, your spongy lever confirms it, it is overhaul time, no buts, ifs, or maybes just do it and be glad (safe). As mentioned; remove, clean, replace parts as needed, the master cylinder, caliper(s) and caliper slide pins. Seriously consider new hoses while you are there. Front brakes that work great, priceless. If this is beyond your comfort level find someone who can do it for you.

 

[djg42]

i think ill replace the brake line while am at it. Is their a specific type/brand thats better to use? Thanks,
DG