Front end clunk under braking

Ok bike is a 1992 VFR 750
28k miles, bought it from a member here at 24-25k.
Has stainless braided lines. Clean DOT4.

It has developed a clunk when applying the front brakes hard. Does not matter if it is high speed or rolling around.

I suspended the front end(ratchet straps to ceiling lol) and checked the steering bearings, all is smooth and i cant feel any movement.

Moved to the brake calipers, right side is solid, left side has a movement to it, can hear metal on metal contact.

Is this the source of my noise?
And is there a cheaper mounting pin than oem?

ALSO, my pad wear is uneven, looks as if one piston is further out than the other. Pad replacement and reset them to be parallel?

I scored a set of calipers for 20 on ebay, mounts dont feel that good though, i am going to try swapping pins though to see if i can make a difference.

 

Best thing would be remove your calipers and free up any moving parts and grease with a good brake lube. pins often seize up or a caliper piston maybe stickingon you. if your pads are uneaven I would repalce them at this time.

 

Last time I had a bike do that, it turned out to be one of the forks. Worn out fork spring, noise was the piston hitting the top of the retainer, made a loud "whack".

 

Thanks for the tips, will regrease everything, and replace the pads.

Then re check for the noise before messing with the forks

 

I would still suspect the steering head bearings. You can't generate nearly the same loads "by hand" as you actually get during braking. My suggestion is to pull the top triple and clean/grease everything and retorque to the proper value. That very likely could clear it up for you. Good luck!

 

^^^^ i agree with him^^^^

 

Brakes could use a service too possibly. Satisfying job fer sure, fun working with brake fluid you know, after that its anti-freeze. Both pistons should be out an equal amount on your calipers, if there not, there is smigma behind the seals. Whats you need is a full-on brake re-furbishing.

Noise when you apply brakes could be a number of things, like der Ice-Hunchin/and Jamie sed, could be der steering bearings. Gud luck, you got the best bike yah know :smile: Keep us Posted!!!!

 

Fiddled with it today
Definitely aint the brakes making noise. Unscrewed the top of the forks, and the noise still existed.

Going to takae apart the front end and inspect the steering stem bearings, i'll have all balls on hand if i need to replace.

How bad is it to do drive out the old races and put in new ones?

 

With a long flat bladed screwdriver and gentle tapping it isn't a problem to get them out. Use the old race to drive in the new one.

 

Its snot that bad really, I happen to have a nice (shameless plug) Snap-On race-punch along with nice compact chipping hammer. You gota love hammering on shit! Anywho0-I am sure you could use a crusty (not to be confused with crustyrider) screwdriver with a claw hammer if you wana get medieval on its arse. Once you buttoned up everything after you knocked your old races oot and installed your new ones, you need to make sure the slotted collar nut is not too tight, this is done by feel bascially. You should be able to flop the bars from side to side without much help from your hands. Hope this helps. My steering head bearings lasted over 70,000 miles, once I replaced them, it was a nice maintenance item, that I was glad to replace.

 

He was just paranoid about saying, "racist-punch"

:tongue:

 

I had the same symptoms as you, including uneven pad wear and the weird clunk. This weekend I put new brake pads on and discovered one of the brake pistons was stuck about half way out. I forced it out by putting in a piece of wood in front of the "good" piston and pumped the brakes, the other one popped out. Note that you should put a bucket underneath it to catch the fluid.

Then I cleaned up and greased the pistons, as the seals looked ok.

Clunk is gone, and bike steers better and goes like stink again !!!! Pad was obviously sticking and I didn't notice it.

 

This lasted a few days, then started sticking again.

I ended up having to replace the seals too. One of them was chewed up, but I bought a full set of seals for all 3 calipers. I always do this as I reckon if they've all been on the bike the same length of time, and one of them has failed, the others can't be far behind. Also put new pads on while I was at it.

Not a difficult job actually, I used a Dremel with a fine wire brush to remove the crap stuck to the pistons, getting the air bubbles out after re-assembly was the hardest part !

Now it's working perfectly again.

 

Where did you attach the straps??

If they were on the frame, you're ok but if they were on the upper tripple, you will not get the proper results. You sound fairly mechanically inclined so I'm thinking that you lifted on the frame and not the steering head but I ask just for clarification.

Changing the bearings and races at this mileage is a good idea anyway and the aren't that expensive. The only tricky part is getting the inner race off the lower tripple as there isn't much to get a grip on to pull it or punch it off. A lilttle heat can help here too.

 

Project has been set aside. Again.
Its stored an hour away at my buddys. Its a pain to get a time when both of us can work on it.
Hopefully i will do it sometime over the winter.


I have a feeling i will end up new steering head bearings, brake caliper pins/slides and pads.

And yes i lifted from the frame:crazy::biggrin:

 

Bike is rolling around again finally

No noises from the front end at all

Used the all balls kit. Races in the freezer and then drove them into the head. Drove the bearing onto the stem with pipe+hammer. Not bad at all to do.

Now to get it running