Front brake lever

[Ken4004]

Great advice from everyone but please let me know how far you can pull your brake lever back before it becomes difficult so the gap between the handle bars and the lever as I said be for mine geo is around 15 mm just interested to see what gap other people had after bleeding their brakes.

[ST1100]

...I pull the lever back as far as I could and zip tied it to the handlebar, took the reservoir cap off and left it overnight, it worked.

That, and gently tapping on all the lines and hoses with the (plastic) handle of a screwdriver to dislodge the adhered micro-bubbles in there...

I'm pretty sure genuine Honda items actually contain steel braiding sandwiched between two layers of rubber and they shouldn't expand.

Again I concur...

[McCabe-Thiele (Ted)]

Great advice from everyone but please let me know how far you can pull your brake lever back before it becomes difficult so the gap between the handle bars and the lever as I said be for mine geo is around 15 mm just interested to see what gap other people had after bleeding their brakes.

My 400 has the DS replacement master cylinder, I use Silicone brake fluid, the flexi pipe was new in 2021,  the gap between the bar grip and the lever at it's closest point is 4 cms with the lever  pulled in hard.
Its a really solid front brake, not spongy.

[exvalvesetdabbler]

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At least 15 year old OEM hoses and MC rebuild kit. And using DOT 5 brake fluid

Regards
Dave

[Oddjob]

My experience of the inside of the Honda brake lines was that the braiding was not steel, more like nylon or even cotton. It was white looking iirc. I could watch the lines expand under pressure, which is why most got braided stainless steel lines back in the 70s.

[Ken4004]

Thanks for the info everyone looks like I need to do some rework but will start with another brake bleed .

[Mikep328]

After the brake bleed, and assuming you have new brake lines that won't be expanding when you apply the brakes, bed in a set of NEW, brake pads properly and you will likely be happy with the front brake.  Bedding in the brakes takes some effort, it's not a matter of just going out/applying them a few times.  It is not really necessary on modern brakes but it will make a DRAMATIC difference/improvement on these brakes.  I suggest the Vesrah Organic pads which were best of 5 different compound pads I tried when I restored my 400's front brake. 

Here is the bedding-in procedure I followed, it was posted on the site by OddJ in Aug, 2023: 

 "Clean the brake disc off with brake cleaner to remove any existing pad transfer material, a gentle rub with some fine wet and dry won't hurt either. Then take the bike out and do 15 gentle brakes from 30mph and then a 2 mile cool down followed by another 15 or so from around 45mph using moderate brake pressure followed by another 2 mile cool down run, then stop to see how the discs look. You should clearly see some pad transfer, it's a sort of blue/grey mist on the surface of the disc, then do 15-20 full on braking sessions from around 65-75mph, dropping the speed down really quickly but rolling off when around 10mph and then back up to speed later, followed by a 5 mile cool down run."

[Ken4004]

Thanks Mike great advice , I like the sound of the bedding in the brakes process.

Looking at all the advice I have had there must be air still in my brake lines so will end a couple of hours at the weekend to try and get it out.
I have bleed my brakes many times on my Triumph 1050 triple with no issues at all but I have always started with a filled system and used my myti vac to draw through new brake fluid and just top up the reservoir only normally takes me 15 to 20 minutes with no drama but with new pipe work and master cylinder there’s lots of air trapped everywhere.
Anyway I’ll get there again just a little patience needed.




quote author=Mikep328 link=topic=32445.msg315691#msg315691 date=1768827108]
After the brake bleed, and assuming you have new brake lines that won't be expanding when you apply the brakes, bed in a set of NEW, brake pads properly and you will likely be happy with the front brake.  Bedding in the brakes takes some effort, it's not a matter of just going out/applying them a few times.  It is not really necessary on modern brakes but it will make a DRAMATIC difference/improvement on these brakes.  I suggest the Vesrah Organic pads which were best of 5 different compound pads I tried when I restored my 400's front brake. 

Here is the bedding-in procedure I followed, it was posted on the site by OddJ in Aug, 2023: 

 "Clean the brake disc off with brake cleaner to remove any existing pad transfer material, a gentle rub with some fine wet and dry won't hurt either. Then take the bike out and do 15 gentle brakes from 30mph and then a 2 mile cool down followed by another 15 or so from around 45mph using moderate brake pressure followed by another 2 mile cool down run, then stop to see how the discs look. You should clearly see some pad transfer, it's a sort of blue/grey mist on the surface of the disc, then do 15-20 full on braking sessions from around 65-75mph, dropping the speed down really quickly but rolling off when around 10mph and then back up to speed later, followed by a 5 mile cool down run."
[/quote]

[Ken4004]

Spent a wet afternoon in the garage looking at the front brake and after trying to bleed them again I noticed some brake fluid drips at the lever where it touches the plunger/ master cylinder.
I have therefore decided to take the master cylinder apart to inspect the seals and all looks ok so seals are not damaged they are  the correct way around and there are no scores that I can see in the bore .
I took the parts to my local bike shop and he inspected all the parts and couldn’t see anything wrong but did comment about the quality of the master cylinder seal kit I used.
I must admit it wasn’t an original Honda kit which are £65 but one From Wemoto  in Brighton at £18.00, anyway to cut a long story short I have asked the bike shop to order me another kit which is going to be £35.00 instead of the £18 I spent on the last kit so hopefully it will be a little more successful .

A friend of mine at work had a favourite saying “pay cheap pay twice “ so this could be a good example lesson learned.

I will also take the brake assembly with me to the bike shop so they can check to bore because I don’t want to take it apart again, I don’t mind most of the rework but getting that circling out is a Pain.

[Mikep328]

FWIW, when I did the work on my front brake I replaced all parts with genuine Honda parts.  I figured that since the brakes are a critically important component I did not want anything but Honda parts, regardless of price.  This included removing a new aftermarket caliper piston a shop had installed for the previous owner just a few months prior.  But since the brake was TERRIBLE and essentially useless when I bought the bike, I figured the shop didn't actually test the brakes, just installed some new parts/new fluid, made sure the lever felt firm and that was that. 

[Ken4004]

Well I am glad to say my front brake is now really good , as soon as the lever is pulled in pressure is felt at the brake lever immediately so all good.
So the issue with the leak was a small scratch inside the master cylinder bore so I polished it out with fine emery paper and flushed it clean.
I bought a better quality master cylinder repair kit fitted it  and then re bleed the brakes which took about an hour, I would say if you pull hard on the brakes now the gap between the brake lever and handle bars is now 40 mm instead of 10 to 15 mm, I believe the movement is due to a little flex in the brake calliper which is to be expected but I just check tightened the caliper bolts so all is good.
So now just have to bed in the brake pads.

I really appreciate everyone advice and hopefully should be on the road once the weather improves , I just need to go over the whole bike again and check everything is tight and correctly assembled ( shake down) I might even take it into the local bike shop and get them to do an MOT test even though it doesn’t require one anymore just in case I have forgotten something better safe than sorry.

I expect like me your all glad this saga is resolved your probably sick of hearing about it.

[Rayzerman]

One thing I find occasionally helpful when I feel I've bled as best I could and it still feels a little spongy.... tie the lever to the handlebar, so everything is under some pressure, then tap the lines starting at the bottom (questional benefit, but what the heck)... leave it overnight.  Lever will likely be firm in the morning, meaning air bubbles migrated up into the reservoir.  A quick squirt should confirm no air.

[Ken4004]

Hi Razerman while bleeding the brakes I did a combination of tapping the hoses and the continued with the bleeding, I will however have another look tomorrow but it really is very firm at the moment so I think I have cracked it

[exvalvesetdabbler]

Well done ken.  Not everyone chiming in to this thread doesn't mean we're not engaged.  We're probably making notes in case it happens to us!

Regarding any micro bubbles left in there, once they get to the top you can usually remove them by just gently working the lever by about  10 cm a few times, you will see them coming out one of the tiny holes in the reservoir.

Regards
Dave

[Ken4004]

Hi Dave

Yes I have noticed this already and will keep as you say pumping the lever slightly to encourage the last of the air out of the system.
With regards to the leak I had the scratches I found in the bore were hard to see but luckily not too deep so we’re relatively easy to polish out.
If I replace the master cylinder on any future bikes I will probably inspect the bore surface with a lot more care , this time I also used lint free clothes to wipe all the components and the bore as any imperfections or dirt present will damage the seal.