soft rear brake pedal.


Information and questions on GL1800 Goldwings (2001-2017)
Post Reply
User avatar
WingingEd
Posts: 3
Joined: Fri Aug 26, 2011 1:55 pm
Location: charleston, wv
Motorcycle: 2003 GL1800

soft rear brake pedal.

Post by WingingEd »



I am not a beginning mechanic, but it's been a long time since I've been in the profession. So over the last year my 2002 GL1800 has developed a soft rear brake pedal on the first press. Let it up and hit it again and has a full pedal. So today I replaced all the pads, front and rear. Also replaced all the fluid although it looked good and clean. I followed the bleed sequence using the old pump up and bleed method. All this changed nothing at all. I never got air out if any of the bleeders and had good spray pressure when opened. I know I could be looking at replacement of one or more components. What have you found that's most likely the problem in a situation as this?


User avatar
WingAdmin
Site Admin
Posts: 22292
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (sold)
1998 XV250 Virago (sold)
2012 Suzuki Burgman 400 (wife's!)
2007 Aspen Sentry Trailer

Re: soft rear brake pedal.

Post by WingAdmin »

Assuming there is no air in the system, 90% of the time you need a rebuild - either the caliper or the master cylinder. The rubber bits in them just wear out.

The other 10% I have seen due to bound-up caliper slider pins not allowing the caliper to slide - particularly if only one is bound up, in which case the caliper is actually bending to engage the brake rotor.
User avatar
WingingEd
Posts: 3
Joined: Fri Aug 26, 2011 1:55 pm
Location: charleston, wv
Motorcycle: 2003 GL1800

Re: soft rear brake pedal.

Post by WingingEd »

OK, thanks!
I think I'll start with the rear master cylinder replacement. I'm wondering... I noticed that the left fork seal is blown and has lost a lot of fluid. Since that's the side that also has the anti-dive unit, is there a chance the soft rear brake pedal is related to that?
User avatar
Andy Cote
Posts: 775
Joined: Sun Feb 27, 2011 11:38 am
Location: Windham, ME
Motorcycle: 2015 Goldwing, basic black

Re: soft rear brake pedal.

Post by Andy Cote »

I don't think so.

Many folks will disable the anti-dive during a rebuild.

Have you checked (with a dealer, not online) to see if all recalls are up to date? Specifically, numbers 20, 22 and 23 deal with brake pedal master cylinder. Although the symptom the recall addresses is a sticking brake, this may be related but will at least get you new parts for free from Honda.

There is also a specialized bleeding procedure that adds a step to the Honda service manual. Did you use that?
2015 Goldwing, basic black

Previously: GL1200 standard, GL1200 Interstate, GL1500 Goldwing, GL1500 Valkyrie Standard, 2000 Valkyrie Interstate, many other Hondas
User avatar
WingingEd
Posts: 3
Joined: Fri Aug 26, 2011 1:55 pm
Location: charleston, wv
Motorcycle: 2003 GL1800

Re: soft rear brake pedal.

Post by WingingEd »

The sequence I used that seems to be the most recommended according to my search is,
1) Using the Front Brake Lever - Front Right caliper Upper bleed nipple
2) Using the Front Brake Lever - Front Left caliper Lower bleed nipple
3) Using the Rear Brake Pedal - Front Left caliper Upper bleed nipple
4) Using the Rear Brake Pedal - Front Right caliper Lower bleed nipple
5) Using the Rear Brake Pedal - Rear caliper Lower bleed nipple
6) Using the Rear Brake Pedal - Anti Dive plunger
7) Using the Rear Brake Pedal - Rear caliper Upper bleed nipple


I did these steps several times trying to get a good brake pedal. When I wasn't successful, I buttoned everything up and took it for a test ride. To my surprise, and beyond my explanation, I had a great pedal and the brakes worked almost good as new. I now even have good stiff pedal sitting still in my driveway. Can't explain it, but I'll certainly take it. So now I will order the fork seals and bushings. Hope that gives me a smoother ride. I bought the bike new 19 years ago but our family situation changed shortly after and it has sat a lot. Only has 30k miles on it so a lot of things have deteriorated. Now I'm trying to restore it to it's former glory.
User avatar
Andy Cote
Posts: 775
Joined: Sun Feb 27, 2011 11:38 am
Location: Windham, ME
Motorcycle: 2015 Goldwing, basic black

Re: soft rear brake pedal.

Post by Andy Cote »

WingingEd wrote: Sat May 29, 2021 7:50 pm The sequence I used that seems to be the most recommended according to my search is,
1) Using the Front Brake Lever - Front Right caliper Upper bleed nipple
2) Using the Front Brake Lever - Front Left caliper Lower bleed nipple
3) Using the Rear Brake Pedal - Front Left caliper Upper bleed nipple
4) Using the Rear Brake Pedal - Front Right caliper Lower bleed nipple
5) Using the Rear Brake Pedal - Rear caliper Lower bleed nipple
6) Using the Rear Brake Pedal - Anti Dive plunger
7) Using the Rear Brake Pedal - Rear caliper Upper bleed nipple


I did these steps several times trying to get a good brake pedal. When I wasn't successful, I buttoned everything up and took it for a test ride. To my surprise, and beyond my explanation, I had a great pedal and the brakes worked almost good as new. I now even have good stiff pedal sitting still in my driveway. Can't explain it, but I'll certainly take it. So now I will order the fork seals and bushings. Hope that gives me a smoother ride. I bought the bike new 19 years ago but our family situation changed shortly after and it has sat a lot. Only has 30k miles on it so a lot of things have deteriorated. Now I'm trying to restore it to it's former glory.

Glad to hear all is better. I thought there was a How-To post on this but I didn't immediately find it.

For future reference, there is a junction block near the steering stem that sometimes can trap a bubble. You can loosen the brake line to bleed this block as well as loosen the banjo bolt on the secondary master cylinder. Use a proper line wrench. Just be extra careful as there is no bleed nipple and fluid can go anywhere.

Besides damaging plastic parts, brake fluid can cause blindness!


2015 Goldwing, basic black

Previously: GL1200 standard, GL1200 Interstate, GL1500 Goldwing, GL1500 Valkyrie Standard, 2000 Valkyrie Interstate, many other Hondas
Post Reply