trying to nail down brake problem

[bill v e]

2000 is w over 180,000 -  front brake pads replaced twice in last 20,000 miles or less.  local dealer can't seem to diagnose exactly what to do.  thinks i may need new brake lines or new master cylinder or new rotors.  brakes do not catch until brake lever fully engaged.  not willing to tear down myself but don't feel i can fully trust anyone else local yet.  wish i knew someone i could bring the old girl to that would be able to accurately diagnose (live in oklahoma near ft smith arkansas).  i suppose i may have dealer replace pads again (oem) and clean/rebuild calipers while i remove rotors and have them turned just to make sure they are not warped.  will ask them to inspect brake lines for any indication of binding.  can't figure out what else to do.  any suggestions?

[Blackduck]

By fully engaged I take it you mean the lever is right in against the hand grip. Before removing anything I would get hold of a dial indicator and check the discs for runout/warping. While you have it jacked up to check the discs check the wheel bearings as well.
Are the pads worn down and are they worn evenly?
Could be a problem in the master cylinder, when was the fluid last changed?
Have you had this bike from new? If not do you know it's service history?
Cheers Steve

[RonW]

.... brakes do not catch until brake lever fully engaged.  wish i knew someone i could bring the old girl to that would be able to accurately diagnose.

at the least we can attempt a diagnosis over the Internet before spending all the money on replacing this and replacing that, plus labor costs. There might be a better option. My thinking on .... "do not catch until brake lever fully engaged" .... is possibly due to a defect at #17 or at point #2 (brake line) in diagram below since a defect there would affect the hydraulic pressure on both side's front brakes. The engagement tab on the brake lever could be worn where the tab pushes the piston into the brake master cylinder. Or the contact points could be slipping pass each other for whatever reasons. Or a worn bushing for the lever bolt #19. Do you have stock brake levers? Have you tried pumping your lever to see if it makes a difference if it does it's definitely the master cylinder's piston.


[Edit] oh, wow .... 180,000 miles! Didn't see that however the rotor would wear out too thin?

[sugerbear]

and if you haven't done so yet, replace all the lines. at 180,000 their tired and soft.

[Ricky-D]

I guess the first and most important thing to do would be to bleed the system and insure there is no air bubble stuck somewhere in the system.

The only real problem you have right now is the lever having to move so far to get some braking action, which could be dangerous. So, my questions regarding this is: Do you feel that you can lock the front brakes up with the lever in this position. I mean, is the braking still reliable even though you have to move the lever that far?

I am not a believer in turning down the rotors on a motorcycle and especially on the Valkyrie. The rotors just don't have enough meat on them to begin with and turning them will surely get them to the point where they need to be replaced.

The calipers are floating type calipers and can handle a little bit of runout with no problem at all.

Two sets of pads in 20k mile is very troubling and very unusual. Did you keep the old pads so you could inspect them. Who's decision to change them?

You say nothing about the rotors. Are they originals or have they been replaced?

It sounds like you have no access to any tools but it would be a great help to you if you could get the bike's front wheel off the ground and be able to see (then) more clearly what is going on with the calipers. You know, being able to spin the wheel and all!

What your dealer is suggesting is to just about replace the complete front braking system. Seems a bit extreme at this point. Rebuilding the calipers is a good idea especially if they are still in original condition. To replace the rotors depends upon the condition of the ones you presently have.

***

[John Schmidt]

+1 on rebuilding the calipers and the master cylinder if never done before. You also might have a rounded out pivot for that brake handle causing you to lose action when you pull it in. But before putting the bike back on the road, I'd most definitely replace those brake lines with SS units. If the lines on there now are the originals, they're way past due for changing. As mentioned, they get soft and will expand when you apply pressure. You need to replace all of them....front and rear. As for the rotors, they need to be really bad before turning them down...which I also don't generally suggest on a bike. Others will disagree with me which is their choice. I'd replace them with GL1800 items in front, get an OEM replacement for the back if needed.  The 1800's are less expensive and fit the Valk.

Good luck, keep up posted.

[Earl in Pensacola]

Another 2 cents-- I have to agree with Ricky-D at least in part.  First off: There is, as far as I can find, no shop around here that CAN turn/machine the Valk's rotors.  Second--as Ricky-D said there just ain't enough rotor to turn it and still have a safe rotor to use.  Haven't seen any answers to a lot of very good questions yet.  The two suggestions that struck me as the first I'd check was: Are the levers OEM"s, if not, that might be the problem. If they are: they still might be the problem by excessive wear.  The other most logical source was the internals of the master cylinder.

[RonW]

Earl, I think that the piston isn't retracting full back out but hung up for whatever reasons. That's possibly why the brake lever doesn't engage until it's squeezed all the way in. The tab on the lever may not be overly worn. I guess billve could remove the lever and fiddle with the end of the piston under the rubber booth. Btw, where is bill v e?? Has anyone seen him lately.

[bill v e]

really sorry for the late feedback - only get a few days a week when i am not working or sleeping!  i've put all but the first 800 miles on this bike.  had the calipers cleaned out good about 80k ago or so.  all parts are original. had the brake fluid chngd about 20+k ago.  i will look into lever possibility and master cylinder rebuild perhaps.  these models are very similar to the 1500 goldwings and i know of a few that have close to and over 300,000 miles on original master cylinders, calipers and brake lines - forgot to ask about rotors, so not sure re them.  my main problem is finding trustworthy mechanics that are able to diagnose w/o oversight by shop managers that just want to replace everything they can to protect themselves from the sue happy i guess.  the brake pads are wearing unevenly as the pistons are not evenly engaging or are sticking.  not doing any serious driving and only cautiously on familiar roads till wednesday when i will be having someone new do a rebuild job on the calipers and go from there.  grateful for you feedback and will try to keep you posted.  thanks. 

[Blackduck]

With uneven wear you are back looking at caliper problems.
Would be the first place to look and keep the cash in your pocket on the master cylinder etc.
Would still check for disc runout and the state of the wheel bearings.
Cheers Steve.

[Ricky-D]

It is fairly easy to see the brake pads in the front calipers employing a flashlight and a mirror.

I would suggest to have a friend operate the brake lever while you observe the action of the calipers.

There should be no obvious action with the pads when the lever is depressed and there should also be no obvious action with the pads when the pressure is released.

If you do see movement, the problem is with the calipers, and the pistons need to be cleaned along with the caliper internally, and new seals.

***

[bill v e]

ok - had the calipers rebuilt and pads replaced.  definitely need to replace rotors which are worn and warped.  will be replacing front tire soon so will replace rotors then.  to replace rotors, is it just a matter of unscrewing the six allen bolts, or is there more to it than that?

[bscrive]

Thats about all there is.  Just make sure to use locktite when you put the bolts back.