Front brakes are mushy, what should I try?

[89-300ce]

I've just finished an extensive bleeding session on the system. I pushed the pistons in and then cracked the banjo and carefully bleed there and re-torqued . I put grease on the bleeder threads and used a small wire tie to lock my bleed canister hose to the bleeder and then bleed with the banjo fitting on the bottom, next with the cylinders vertical above on another, and again with the bleeder port vertical. My system is clean as can be. :good:

Before this I was sure that my system had no air as I've bleed many cars and bikes over the years including the VFR which has the most complex system of hoses and secondary master cylinders, etc. imaginable. I could almost pull the lever to the bar and braking was weak.

I was about to order a stainless line set when I saw this thread and am sure glad I did because I would have installed the lines and had no improvement. If you think your lines have flex pinch them off as mentioned in previous posts. Mine had absolutely no flex so I saved myself some money and work.

In the end I now have a lever with half the travel that I did before. I can't get it anywhere near the bar and it feels somewhat similar to the VFR. A notable improvement and just by careful bleeding. Whether this improves my front brake will need to be seen but I'm hopeful.

Right now it's sitting with the brake lever pulled in. I'll leave it like that for a few days for good measure.

 

[jnp17331]

Worth Repeating
Try checking for clearance with a feeler gauge between outside of the brake disc and both caliper holders
should be 0.028 front and back.To much clearance here can cause mushy brake syndrome.
Once upon a time they were perfect. Over the years the wheel was probably off at least once. If then it wernt reinstalled to original specifactions (0.028 clearance) between outside of the brake disc and both caliper holders. But instead were set way loose the piston travel in tha master cly needed to fully apply tha brakes for a proper bleed will be excessive.Now a few years later you decide to tune up tha brakes .Its easy to screw this up, I been tinkering wit motors for 40 years and I missed it on mine.Once! :BigGrin: and had your exact results, no guarantee this is tha problem in your case . But I figgered its at least worth talking about.
Also I suspect tha Master Cly's on these motors is slightly undersized for tha job making bleeding a tricky job sometimes.
PS: pump tha heck out of it before tie,n down but dont bottom it out while doing so, short rapid strokes then tie er down whilest you hold that last stroke.

 

[chuck c]

There's one thing I haven't tried yet. I'm going to try bleeding both sides at once. Maybe I'm chasing a bubble around the crossover. I figure if I suck fluid up both sides at once, any trapped air has got to get into the hose to the master and out.

 

[chuck c]

Thanks, I will check this. It's very possible I cocked something when I put the wheel back on.

jnp17331 » Sat Sep 03, 2016 6:24 am[/url]"2mz8bbi]
Worth Repeating
Try checking for clearance with a feeler gauge between outside of the brake disc and both caliper holders
should be 0.028 front and back.To much clearance here can cause mushy brake syndrome.
Once upon a time they were perfect. Over the years the wheel was probably off at least once. If then it wernt reinstalled to original specifactions (0.028 clearance) between outside of the brake disc and both caliper holders. But instead were set way loose the piston travel in tha master cly needed to fully apply tha brakes for a proper bleed will be excessive.Now a few years later you decide to tune up tha brakes .Its easy to screw this up, I been tinkering wit motors for 40 years and I missed it on mine.Once! :BigGrin: and had your exact results, no guarantee this is tha problem in your case . But I figgered its at least worth talking about.
Also I suspect tha Master Cly's on these motors is slightly undersized for tha job making bleeding a tricky job sometimes.
PS: pump tha heck out of it before tie,n down but dont bottom it out while doing so, short rapid strokes then tie er down whilest you hold that last stroke.

 

[joedrum]

chuck c » Thu Oct 06, 2016 8:34 pm[/url]":22qampng]
There's one thing I haven't tried yet. I'm going to try bleeding both sides at once. Maybe I'm chasing a bubble around the crossover. I figure if I suck fluid up both sides at once, any trapped air has got to get into the hose to the master and out.
bleeder.PDF

actually a great idea and will work great if you use the method i will explain ...with single piston calipers this will for sure get rid of the air in system cross over tube .....or where ever it is ....

take both calipers off the rotors....take the pads off calipers....need two 5"c clamps ...with pads off the c clamps will fit inside the brake piston on calipers ....with both clamps on calipers have someone help you turn both clamps down till they bottom out .....then pump brakes pistons back out loosening clamps along the way and get both pistons pumped up to just before they look like they wil come out of caliper ....then again turn the clamps down together and bottom the pistons again ...this moves the fluid back through the return hole in master and clears it good and also pushes the air out of system.....this way you get the biggest push of fluid to rid the system of air ....if your by yourself like i am always do one caliper at a time and leave the other side on rotor and do each a couple times or as many as you want ...with the other side on rotor it cant go far to that side .....ever since i figure this out on hooch ive never have a problem with spongy brakes or clog return hole ....after first side is done just leave clamp on it and do other side ....once both are done put pads on and mount calipers ...brakes will be good

 

[chuck c]

Here's a diagram of what I plan to try. I have a plate to cap the MS but I need to drill it and get the hose glued in. Plan to do that tonight so it's ready tomorrow. I will grease around the bleeders and hose connection to keep air from getting in there.

 

[chuck c]

We might be getting somewhere. If I'm measuring correctly this mount is far out of spec. It's .063 on the bottom and maybe .120 on top! One pic is looking down on the right caliper. Sooo now I have to mess with the axle clamps? I know they are directional and I think I have them on right, but I'll check in the morning. Could it be that simple? It never occurred to me that the axle clamps would come into play but it makes sense the position of the wheel and forks on the axle sets the position of the calipers relative to the disks. :beg: Please let this be it!

 

[jnp17331]

chuck c » Yesterday, 7:56 pm[/url]":2qi4gp52]
We might be getting somewhere. If I'm measuring correctly this mount is far out of spec. It's .063 on the bottom and maybe .120 on top! One pic is looking down on the right caliper. Sooo now I have to mess with the axle clamps? I know they are directional and I think I have them on right, but I'll check in the morning. Could it be that simple? It never occurred to me that the axle clamps would come into play but it makes sense the position of the wheel and forks on the axle sets the position of the calipers relative to the disks. :beg: Please let this be it!

All four corners should be equal 0.028 min. Just loosen tha axle clamps on tha axle nut side then slowly tighten tha axle nut till you have tha proper clearance then tighten tha axle clamps. check carefully that nothing drags and yer done.

 

[chuck c]

I will try this today. What I can't figure is why it causes the problem. I'd think the piston would extend and caliper would just float until it made contact and distance would be taken up by the piston. UNLESS because the calipers are directly linked, they must be equally spaced from the disk! A single lever pull doesn't push enough fluid to move both pistons enough unless they are close enough to the disk! It might also explain why one side almost works and the other doesn't at all. That makes a ton of sense. I will adjust as you advise and let y'all know what happens.

I guess I never ran into this before because I've only worked on single brakes before. They might have a spec like this but because there's only one it's not as critical.

 

[chuck c]

I'm mystified. The axle fixes the spacing of the forks and I have them correctly a far in as they go. Are there supposed to be shims to move the caliper mounts further?

GUYS! I just looked at my parts bike and the axle nut is on the other side! Which one is correct?

 

[BikerJoe]

Nut should be on kickstand side.

 

[BikerJoe]

quote="chuck c » 23 minutes ago"]
I'm mystified. The axle fixes the spacing of the forks and I have them correctly a far in as they go. Are there supposed to be shims to move the caliper mounts further?

GUYS! I just looked at my parts bike and the axle nut is on the other side! Which one is correct?
[/quote]

Dont be mystified Bro , over tha years anything could of been done to these old bikes. On tha 81 tha axel is held captive on tha right starboard side :BigGrin: and adjusted as I described on tha port kickstand side :BigGrin: .
If its excessive travel it takes more to fill em and tha master cly aint always up to the job of pushing enuff fluid for proper bleeding

 

[chuck c]

Thanks for clarifying the R/L issue. Mine is right, the parts bike is wrong.

This gap setting is not making any sense. The sleeve nut has be bottomed or the wheel can move side to side. How am I supposed to move the forks to set the .028 gap to the backside of the disks? Use small words and plenty of them.

 

[chuck c]

All four corners should be equal 0.028 min. Just loosen tha axle clamps on tha axle nut side then slowly tighten tha axle nut till you have tha proper clearance then tighten tha axle clamps. check carefully that nothing drags and yer done.

This gap setting is not making any sense. The sleeve nut has be bottomed or the wheel can move side to side. That's can't be used for fork adjustment! Use small words and plenty of them.

 

[BikerJoe]

chuck c » 50 minutes ago[/url]":6o62ttan]
All four corners should be equal 0.028 min. Just loosen tha axle clamps on tha axle nut side then slowly tighten tha axle nut till you have tha proper clearance then tighten tha axle clamps. check carefully that nothing drags and yer done.

This gap setting is not making any sense. The sleeve nut has be bottomed or the wheel can move side to side. That's can't be used for fork adjustment! Use small words and plenty of them.

Its Lemonade Bro. Read it Lemonade :BigGrin:

 

[BikerJoe]

chuck c » Today, 2:21 pm[/url]":2708r3nc]
All four corners should be equal 0.028 min. Just loosen tha axle clamps on tha axle nut side then slowly tighten tha axle nut till you have tha proper clearance then tighten tha axle clamps. check carefully that nothing drags and yer done.

This gap setting is not making any sense. The sleeve nut has be bottomed or the wheel can move side to side. That's can't be used for fork adjustment! Use small words and plenty of them.

Its Lemonade Bro. Read it Lemonade :BigGrin:
[video]https://www.youtube.com/watch?v=EnR9ah0v1o4[/video]

 

[chuck c]

So, are you going to help or not? "pull the fork outward"?
The axle nut must be all the way in or the wheel can slide on the axle. There's no "adjusting" with it.

 

[jnp17331]

HaHa Im trying Bro. just do what I wrote.All four corners should be equal 0.028 min. Just loosen tha axle clamps on tha axle nut side then slowly tighten tha axle nut till you have tha proper clearance then tighten tha axle clamps. check carefully that nothing drags and yer done. left side tight right side loose. slowly tighten axle nut to achieve correct clearance. with tha right caps and nut loose tha forks spread on their own. If you over tighten tha brakes will lock tha wheel. hence .028 clearance in case of wobble ect nothing is perfect. Its a unusuall setup but tha info Im giving you is right out of the manual. Read tha stuff with tha pics I posted, its so simple to do but hard to explain good :BigGrin:

 

[chuck c]

You're just repeating and not reading my questions.

Even this doesn't help. It doesn't agree with what you're sort-of telling me.
https://goldwingdocs.com/forum/viewtopic.php?t=68
Go to step 21.

21. Insert a 0.7mm feeler in between the caliper mount and the rotor at several spots on both sides of the rotor, on both the left and right sides of the motorcycle. If there is binding, loosen the axle holder nuts and adjust the fork leg in or out as required, then snug the axle holder nuts again and re-check.

"adjust the fork leg in or out" is the part that doesn't make sense. There is no adjustment! on the right side the ridge on the axle is up against the fork so it can't go any closer. Now please 'splain to me how I'm supposed to get the bracket closer to the disk when it's already as far as it can go.

 

[joedrum]

gee this is something ....the fork do move in and out this way ......you can adjust like joe says and try to do brakes see if it helps.... if it dose ..you can always put spacers on axle to make up the gap your talking about .....