Thoughts on T-3 braking.

[Gliderjohn]

I have owned my T-3 since 1989. Over the years have really not had to do much to the braking system other than fluid changes and went to steel lines. This last summer my master cylinder for the combo braking went south and I went ahead and replaced it with a new one. WOW! Guess like shocks wearing out you don't always realize it. Braking in that system is 100% improved. Very happy.
Now...never been happy with my right front brake. Has always required a lot of handle pressure to get much braking and I have never had strong hands and now arthritis is also kicking in. If I replace the stock master cylinder with basically OEM master cylinder do you think I will also see significant improvement? Also is there a modern replacement that might be a bit smaller as my cylinder cap is right up against the fairing?
GliderJohn

[n3303j]

Can't imagine braking changing much if cylinder bore and linkage pivot points remain the same. Its all just ratios. Maintain the ratios and the effort remains the same.

But if things were blowing by bad seals then there would be some change of effective braking.

An odd thing I found out was that the stock Brembo cylinders were specified in metric units that converted to exact USA fractional dimensions! So I went to the local hobby shop (when they still had them) and bought 1/64th wall K&S Metals brass tube with the appropriate bores. I then reamed the master cylinders 1/32nd over and sleeved them with the brass tubing (Loctite RC680 bonding).  Drill the cross holes and 75K miles later I'm still stopping efficiently. Now that's Guzzi Cheap!

PS: If you are going to junk your stock front MC can I have it? Mine has a slight crack from a "high side" exit a few years back. (Now this is really Guzzi Cheap )

[jhem68]

My 1980 SP front brake also requires a lot of hand pressure to achieve maximum effect using only the front brake so that is probably the norm on this era of Guzzi. Good effective braking but requires a strong grip.

I haven't a problem with the master cylinder being tight to the fairing but a PO had installed barbacks so my spacing between the two is not as stock would be originally.

Perhaps this is what you're seeking? https://www.mgcycle.com/index.php?main_page=product_info&cPath=110_112&products_id=1942

By the way that is one fine T3 set up you have there.

Edit: I should have noted that this is what you would use when de-linking the brake system.

To further complicate your choices I would note that the best braking change I've ever made to one of my Guzzi's was to put a Brembo RCS 15 on my single disc Breva 750, although that is a dual piston slave, it went from weak and wooden to very strong and easy two finger control.

[SmithSwede]

What is the friction rating of your stock pads?  Going to a higher rating makes a surprising difference.    But the improved performance comes at the cost of more disc wear

[n3303j]

HH Pads on my T3 ate the front disk to minimums in 100K miles but made stopping a two finger experience.

[Perazzimx14]

HH Pads on my T3 ate the front disk to minimums in 100K miles but made stopping a two finger experience.

HH pads and cast iron disc's do not play well together. I'm surprised it took 100K.

[moto-uno]

 I wouldn't hesitate to replace the front Master with a smaller bore unit from a Japanese bike . If you have any
bike wreckers in your area , try them first for a unit with a smaller diameter piston . You'll then be exerting
greater pressure with less hand pressure , in conjunction with greater lever travel . It's kinda nice to get the
lever closer to the grip where you can exert greater braking power and less arthritic load :) Peter

[Tom]

That option would be dictated by the size of the banjo bolt connecting the brake line to the master cylinder.  Otherwise you'd have to look at replacing the MC, brake line & caliper.  That's if they mount up.

[moto-uno]

  I'm sure there's an exception out there , but , 10 mm is pretty much the standard banjo bolt fitting on most Japanese and Euro bikes .
Heck , even HD at 3/8" is pretty well close enough for any 10 mm  banjo fitting . Peter

[Mr Revhead]

The front right brake on a linked system is only intended when needing to brake HARD and is supplementary to the foot brake (front left and rear) are you trying to do something it wasn't designed for? That being the main brake?

[Gliderjohn]

Thanks for the responses. To keep muscle memory up I almost always use all the brakes when I stop. Was especially into that habit when Ruth could still ride.
GliderJohn

[moto-uno]

  That's pretty much how I ran my Le Mans 2 for decades ( with them linked and all brakes , all the time )
A few years ago I removed the linked braking system and went with the norm , front brake lever for front
brakes . I also used a master cylinder from an old Yamaha Seca 650 . Still works fine . I no longer remember
why I didn't just use the stock MG one , it may work fine , more pressure and more lever travel . The stock
linked system worked great , but , I was frequently on hilly, dirt and gravel roads (visiting friends) and I was
uncomfortable when the front wheel stopped turning going down some hills  . Just some alternate
ways around the matter . Peter

[Tom]

  I'm sure there's an exception out there , but , 10 mm is pretty much the standard banjo bolt fitting on most Japanese and Euro bikes .
Heck , even HD at 3/8" is pretty well close enough for any 10 mm  banjo fitting . Peter

While I tend to agree with you on Japanese and most Euro bikes, that doesn't seem to be the fact with Moto Guzzi.  I've been looking.  Let me know if you find one.  The best option I have so far is rebuilding the MC or taking a working one off one the other bikes.   

[BMCMOTO]

I must be doing something different than everybody else. I watch these discussions with some amusement and rarely comment, but hey it's winter, so here goes. Every Guzzi I have owned and or ridden (I worked in a Guzzi dealership)has had more than adequate front wheel braking as supplied by the factory. My Jackal with single disc did stoppies two up and loaded, someone behind me had to tell me, I never felt a thing. The Mille will stop right smart on one front disc as will the 750 Breva. For me the linked system is a great thing, the bike just settles into a nice stop. When cornering, a little linked braking settles the bike into the corner without upsetting the suspension quite nicely. I've never had any problem with the linked system on dirt, even long downhills nor do I have a problem switching back and forth between bikes with and without. I rarely if ever stop any bike without using the front brake and in fact use it more than the rear on all bikes, linked or not.. As for steering dampers, Guzzi provided them on bikes that came with fairings or were likely have a fairing or windsheild mounted and provided frame lugs for mounting them on others that might get fairings or windshields. Guzzi is famous for their wind tunnel testing!! Do you really think that Guzzi's well known penny pinchers supplied motorcycles with dampers without cause, they were so cheap they didn't even supply grease in some places that needed it, why would they give away dampers that weren't needed.
Just my thoughts on a chilly day here in Michigan. Your mileage might well vary and probably will.

Brian

[moto-uno]

While I tend to agree with you on Japanese and most Euro bikes, that doesn't seem to be the fact with Moto Guzzi.  I've been looking.  Let me know if you find one.  The best option I have so far is rebuilding the MC or taking a working one off one the other bikes.   

I no longer have the OEM master cylinder for my Le Mans 2 , however I have the original front calipers and 2 from a T-3 and all take a 10 mm banjo !  Peter

[n3303j]

HH pads and cast iron disc's do not play well together. I'm surprised it took 100K.

Only wore out one disk in 100K miles.
...but I did wear out 3 pairs of horns! 
Lot easier to hit a button than a pedal (or lever).

[Tom]

I no longer have the OEM master cylinder for my Le Mans 2 , however I have the original front calipers and 2 from a T-3 and all take a 10 mm banjo !  Peter

Do you remember from what motorcycle are you using the MC from?

[moto-uno]

 ^ Yep , reply # 11  . Peter
If you'd like I can see if I can get a pic of it tomorrow .