Bonneville T100 Seized Rear Brakes

Have you checked that the rear brake pedal is not seized on

 

There is no text book answer because rust and neglect do not arise on the new machines disassembled for our education......

As Dilli says there is a chance of hydraulic lock if e.g. something was hung on the pedal but far more likely is corrosion binding pad to disc following repeated heat and damp cycles with condensation during your joint lay up. They can stick hard!

Most T100s have centre stands. Check tyre clearance from the ground! If you start it up and get it warm with front brake applied try engaging first gear and dumping the clutch. Get ready to pull in, If that doesn’t free it off then you need to remove the rear wheel. It sounds like it needs stripping and overhauling anyway. Once the axle is out you can drift the assembly off the disc with a suitable piece of timber and a mallet.

 

Pedal function is less important than movement in the master cylinder under the RH side cover. If you had a long, strong lever you could ratchet strap to the wheel/tyre that would work. 6’ scaffolding pole?!

If I had a friendly neighbour I would whip the wheel off and manhandle the bike on its front wheel and stand onto the bench.......

 

You weren’t brutal enough but I know what you mean........ you haven’t got that many years on me and your bike is only a year older!

The rear brake is a bit ‘on or off’ but I use EBC organic pads for additional feel and would only go to increased bite formulation (HH) when I totally lose my grip! A personal thing but I found adjusting the lever (two locknuts on linkage rod) to a more toe down position increased delicacy of ankle control compared with the factory horizontal setting. It is also easier with less flex in my knees.

Just an observation but stainless discs maybe don’t show brown rust as you might see on a car with cast iron but they do get an oxidised layer. I buff mine occasionally if the bike has been sitting with fine wire wool and wipe off with acetone (Superdrug nail varnish remover).

 

Two things: You need to pull the caliper apart and using a toothbrush warm water and a detergent that does not have salt in it scrub all the parts clean in the warm soapy water. Scrub as much of the pistons as you can as well, scrub the slider pins clean. If there is any corrosion on the slider pins then use a very fine emery wet and dry paper and rub the corrosion off but dont go too hard and use a paper grade of around 800 grit or so. You can put the slider pin in the chuck of a drill and spin the drill slowly while rubbing the paper up and down the length of the slider bar. When you have it spick and span then use a little bit of anti seize grease on the slider bars and a bit on the pistons but not too much and make sure no grease gets on the pads. Also put anti seize grease on the thread of the slider pins and on the thread of the caliper bolts. Also scrub the caliper bolts clean. Do the back caliper every couple of months whether you have used the bike or not as dirt crap and whatever else is on the road will get all through the caliper and corrode very quickly as the back caliper hangs down under the swing arm and collects all the filth off the road. Also use a bit of red rubber grease on the opening to all the little rubber cups and a bit down inside the cups. These tinny little cups cost anything from about 25 English pounds to 50 English pounds to replace them on one caliper.

Before you undo the caliper mounting bolts take the steel plug out from the end of the slider pins and crack the slider pins loose other wise you may have a hard time cracking them loose when they are not held rigidly in place. On the Bonneville rear caliper I dont think there is a plug on the end of the caliper slide pins. On the front caliper there is.

IMPORTANT NOTE:
Make sure you take a good look at how the little copper piece that sits under the edge of the pads is located and which way it goes. Also have a look at the end of the pads and take not of the little copper piece that holds the end of the pads, DO NOT LOSE THEM. Take photos if you can of everything before during and when you take each piece apart so you have a referrence to put it back together. Once you have done it once or twice youll be an expert.

Do both front calipers as well although they dont tend to pick up nearly as much crap as the back one but still need doing.

ANOTHER IMPORTANT NOTE:
Do not overtighten the caliper mounting bolts or the slider pins. If you tighten the caliper bolts too much there is a real risk of destroying the thread they go into as the bolts are stainless and the thread it goes into is Alloy I think. Consult a workshop manual for each model of Bonneville because I think it varies. On my 2018 T120 the torque setting is only 22 nm which is only slightly hand tight but use a torque wrench and dont believe people about the torque settings as I have found they get it wrong a lot and it varies.

Hope you get them cleaned up.