03 Road King front brakes ahve always been spongy from day 1.
Replaced pads, and lines, rebuilt calipers thinking about redoing master cyl.
Anyone else have this problem?

 

Just to let you know, I have the same problem with my '01 RK Classic. I have replaced lines and updated to the 'B' part number for the master cylinder. That helped, for a little while, now I am back to very soft. It has been bled forwards and backwards, no help. A friend was over the other day with his '03 RK and it had the same soft front brake lever. None of my other three bikes display this issue.

 

I'm having the same problem with a 96 springer front.Rebuilt caliper and master cylinder and new line.Will not build anything more than a very soft lever.Tried every method known to man and the same result.The master had some light scoring not able to feel it but could see it.Apparently there's enough damage there to keep it from building pressure.
New master is in the picture I guess.

 

I did some more searching under Road King Front Brake and found where the guys were taking the caliper off, pumping up the brakes and then cleaning the caliper pistons. Apparently that fixed the problem. Not sure if that is what is affecting yours. Here is one link that may help: https://www.hdforums.com/forum/wheel...reak-pull.html

 

This problem is nothing to do with the brake fluid, IMHO. There are various causes of soft brake, other than air in the system, such as the pads/pucks sticking in the caliper due to build-up of brake dust, pistons sticking from the same cause. On one of my bikes I have to strip the front brake and clean where the pads fit at regular intervals. So a thorough clean of your calipers may improve things.

 

Here is a slightly different technique than what was posted on the above link, but the concept is the same.

Remove the caliper and remove the brake pads. Push back either the front set or rear set of pistons and place a block of wood between them to keep them from coming out when you pump the brake handle. Carefully pump the handle, not too much, you don't want to force the pistons out too far. You can then clean one set of either the front or back pistons. This keeps you from having to pry the pads apart and damaging the pads. You will see the ring of dirt, etc. around the piston. Instead of using brake cleaner I used Aviation Simple Green, this does not corrode aluminum like regular Simple Green. Try to find something that won't attack the rubber seals. You can use dishsoap and water, rinse well and dry with compressed air. Should have about the same effect. I used a simple pump bottle with water to rinse.

You may have to hold one piston back with your fingers to get the other one out, mine were stuck, somewhat. After doing one set, remove the block of wood and push back the set you just cleaned and put the wood block between those and repeat for the other set of pistons. I guarantee you this is much easier than prying pads apart, etc. After pushing the second set of pistons back in reinstall the pads and re-mount the caliper.

I was amazed at the difference in brake handle travel, it was like a brand new bike again.

Thanks to those who suggested the original idea, it does work.

 

I have disassembled the calipers and cleaned pistons and walls. No change. Simple system still spongey.

 

I also had spongy brakes on my T-Sport.(2001)
Took off calipers
threw away old pads
cleaned calipers with rag soaked in brake fluid
installed new Master Cylinder
installed SS brake lines
installed new pads
bled all lines

Have plenty of brakes now , like new. Nice and hard lever. Very little travel till brakes start to work.
Previous poster has described good system for cleaning. I will use his system next time.

 

Just fixed my front brakes with a $2.50 can of brake cleaner. Here is what I did:

1. bleed the front lines with new dot5 (2004 FLHR) and purge as much air as possible. you will only have a slight improvement. use whatever DOT# level is printed on the rear res. cover or manual to fill and clean in this an following steps. don't mix dot #'s EVER !!!
2. unbolted left (clutch side) caliper from fork with 12 point 10mm. Leave the line connected. tape towel on fender to prevent chipping paint. rock the caliper side to side to compress the pistons a bit before removing -- it's a tight fit.
3. leave pads installed and pump out pistons with hand lever until the pads touch. check resoviour and make sure it stays full. now remove the pins with a 12 point 1/4" thin-wall socket or box-comob wrench. pay attention to the direction of the pads (there is an inside and outside pad). I had to grind down the closed end of my wrench a bit to fit around the pin. now remove the pins and pads - pay attention to the direction of the pads (there is an inside and outside pad). I use my phone camera to take lots of pictures of this kinda thing for reassembly later.
4. using a 30cal brass bore brush, spray off the pistons with brake cleaner and scrub around the pistons until all traces of black residue is gone and pistons are shiny silver. use red tube on cleaner and spray into crack around the piston in the hole.
5. put some new dot5 on a clean rag and clean/coat the pistons . using old pads and screw driver or a putty knife, pry the pistons back evenly into caliper. be careful not to chip off the brake pad liner if you plan to reuse the pad. another method is to use a putty knife to pry the pistons back into the caliper. don't let the piston ****-sideways in the bore when pushing them back in. using an old toothbrush spray and clean the stamped metal shim-spring deep inside the caliper -- it will be all carboned up too.
6. I needed new pads and got 2 new sets of kevlar-black EBC pads at the local cycle gear store. I replaced my EBC metal pads with them and I love how quiet they are. With the fully functioning caliper now I have 4 times the stopping power using kevlars. that is entirely a personal preference - metal vs. kevlar. I was very hesitant on the kevlars but I'm a happy camper now. We'll see long term...
7. lightly and evenly coat the pins with antiseize and reinstall pad - spread the pad and push them apart with putty knife. re-install the caliper. blue locktight and 28-35 ft-# the caliper bolts. pump the pistons out slowly, watching res. level and topping off with fresh dot5.
8. do the same process with the right caliper. Don't forget to clean off brake fluid from hand controls - with soap and water after you are done. It only took 1/2 a can to clean both sides. I have FULL level brakes now and better than new-bike brakes at 25K. Braking is not a chore any more.

I'd taken the bike to 3 motorcycle shops trying to get this done with no success. The only one who could do it was the stealer for $75 when they ripped me off trying to service my radio under warranty (but not doing that job). - so Merry Christmas and put the $$ you save into some good new front pads if there is any question as to the remaining lining on your current pads.

Bleeding alone with NOT DO THE JOB !!! squirting cleaner into the caliper while on the bike will NOT do the job either. you must remove, scrub, coat, and reassemble it - and bleed it. this message IS THE TRICK !!!

time: about 45 minutes, with searching for the right 1/4" 12 point box end wrench being the hardest part of the job.

Many recommend this be done every 3K miles !!! That's a bit much, however, it probably needs done at least every 10K.
DOT5 won't harm the paint. DOT3-4 will harm paint and cause rusting. water alone will displace dot4 but soapy water is needed for DOT5. There is a really good link on the Lyndall Brake website that I learned this process from- special thanks to them as well.

 

Thanks for this post. After three attempts of bleeding forward and reverse to get rid of the mushy front brake I bought the $3 can of brake clean. Removed the 4 caliper bolts. I was able to get the calipers off my 05 glide without removing fender or wheel and let them hang on the hoses in a bucket next to the covered front fender. I used a small pry bar and screw driver to move pads around (did not want to pry pad surface) while engaging brake handle to expose all 8 pistons, cleaned and reassembled. Brakes are 100%. It took about 30 minutes.
Thanks again,
Steve