Rear Brake Improvements

[eyeguy]

I just got a new to me 2021 t700 and Noticed a drop of fluid near the rear brake caliper on my inspection. The guy I bought it from said that he had bled the brakes a bit to firm them up. They were soft but reasonable on my test drive. Got the bike home road it 50 feet into the shed and not since. Took it for a quick drive today after ecu flash and new exhaust. When I went to use the rear  brake literally no resistance or braking effect. So here is the question. I read a thread where somebody replaced the stock rear master cyl with a think it was yz 250 cyl. Anyone remember that thread or know who did the mod?

He posted a link or at least description and I ordered on as it was only 25$ ish on amazon. When I held it up next to the stock today it looks like more mods might be needed to make it work than I originally thought. So looking for some help to know if I should dive in or just return. I dont think new pads would help my issue as must be getting air in the system?

[Rider 101]

Jump in and see what happens.

 

What was wrong with the original master cylinder?

[mpatch]

1 hour ago, eyeguy said:

I just got a new to me 2021 t700 and Noticed a drop of fluid near the rear brake caliper on my inspection. The guy I bought it from said that he had bled the brakes a bit to firm them up. They were soft but reasonable on my test drive. Got the bike home road it 50 feet into the shed and not since. Took it for a quick drive today after ecu flash and new exhaust. When I went to use the rear  brake literally no resistance or braking effect. So here is the question. I read a thread where somebody replaced the stock rear master cyl with a think it was yz 250 cyl. Anyone remember that thread or know who did the mod?

He posted a link or at least description and I ordered on as it was only 25$ ish on amazon. When I held it up next to the stock today it looks like more mods might be needed to make it work than I originally thought. So looking for some help to know if I should dive in or just return. I dont think new pads would help my issue as must be getting air in the system?

I replaced my rear master with a $18 one off amazon. My bike had the same issue as yours. The new master fixed it and now I have a functional rear brake.

I've been meaning to take the original one apart and see what the problem was. 

The new master was almost a direct swap other than having to drill and tap the mounting holes to a larger size. 

This is the one bought.

https://www.amazon.com/gp/product/B09QHRRX5K/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

[eyeguy]

Mpatch, Thanks for the link. The one you linked is clearly an easier swap than the one the other  thread linked. Could just bolt them with a locking nut?

[mpatch]

11 hours ago, eyeguy said:

Mpatch, Thanks for the link. The one you linked is clearly an easier swap than the one the other  thread linked. Could just bolt them with a locking nut?

You could  use bolts that are the size that it's already threaded for I'm guessing. As long as you snug it up I don't think it could move. 

Luckily a friend of mine had the right size tap so I took the extra 10 min to drill and tap the holes to the correct size. 

I did also use the original reservoir and hose but that's literally a 10 second swap. 

One thing to note it did take a few tries to get it bled. 

When I got everything back to together and what I thought was bled the lever was still super spongy but after bleeding it a few times it firmed right up. 

[Mapbook]

Just fitted a set of EBC pads on the rear firmed up the pedal with more bite.

[Schegge]

After 70.000 km on the bike now with the stock rearbrake (only mod: braided lines) my opinion about the rear brake: the biggest problem of the system is that it draws air in. I would also guess that this mainly is locaded at the master cylinder.  When the bike is standing for a while, sometimes only a night, you get a mushy pedalfeel or/and a longer travel at the pedal.

So before every ride after a longer break, i got used to the procedere that i push the calliper with my foot to the wheel so that the piston get pushed inside the calliper and then pump it up again with the pedal, do this 3 times and there is a hard breakfeel again.

After this procedere im quit happy with the feel of the break and i can reasonable good adjust the breaking power. For shure not so good like my brembobrake on my endurobike but good enough and it fits to the overall technical standard of the T7, good enough but not perfect

 

 

Edited February 12 by Schegge

[AZJW]

As noted on page one of this thread over a year ago, The FIX by Camel ADV makes a world of difference.  Both our T7's have that mod with the OEM master cylinder, works great.

[mpatch]

36 minutes ago, AZJW said:

As noted on page one of this thread over a year ago, The FIX by Camel ADV makes a world of difference.  Both our T7's have that mod with the OEM master cylinder, works great.

 

That was not the issue with mine or many others. The issue we are/were having was the pedal being soft, like full travel with little to no brake activation, like there was air in the lines and after bleeding many times never really fixed the issue.

The new master fixed my bike and cost less than $20. 

[eyeguy]

Scheege, I agree air is getting in the system. Yesterday I hooked up a tube to the bleeder nipple and pumped the crazy soft pedal. Then opened the nipple and maybe 1/4 inch of brake fluid entered the tube. repeated and about the 3rd effort of pumping and opening the nipple with a wrench a push of bubbles entered the tube. This continued for another 3-4 cycles of pumping and opening and then no more bubbles and a firm rear brake. Now we will see how long it lasts?

[Toymaster]

 

On 2/12/2024 at 9:25 AM, AZJW said:

As noted on page one of this thread over a year ago, The FIX by Camel ADV makes a world of difference.  Both our T7's have that mod with the OEM master cylinder, works great.

On 2/12/2024 at 10:06 AM, mpatch said:

 

That was not the issue with mine or many others. The issue we are/were having was the pedal being soft, like full travel with little to no brake activation, like there was air in the lines and after bleeding many times never really fixed the issue.

The new master fixed my bike and cost less than $20. 

 

Mpatch,  I agree.  I've got the "fix" but found out this spring I had zero rear brakes on first use.  After pumping for a while it seemed to  get minimal brakes, must be air in system.  I ordered from the link you posted, thks!