Two rear brake problems (Pointy)

[aesmith]

Hi,

I have a couple of niggles with the rear brake. The first is simple, has anyone found a way to stop the brake pedal seizing solid every few months? What I've been doing each time is to remove the footrest and pedal, clean it all out and reassemble with plenty of grease. It's especially annoying as there doesn't seem to be any warning, the pedal feels fine one day, but seized the next. I was wondering whether oil might be better than grease, so it could be oiled at intervals without dismantling.

The second is the calliper. Although the two sliding pins are perfectly clean and free, when the brake's in service it's very reluctant to actually slide. This means that really only one pad's being used, and in fact over a year or so the outer pad was worn almost to the limit and the inner pad virtually unworn.

Any suggestions?

Thanks, Tony S

[Bibio]

what type of grease are you using?

yes,
1. strip the piston out and clean the seal recesses then get new seals and assemble with RRG.
2. clean out the main large sliding pin then assemble using RRG. dont go to mad with the RRG but at the same time put enough on to give it a good lube.
3. make sure that you have installed the inside pad spring/anti rattle the correct way, there are clips on the spring/anti rattle so it keeps the inner pad in place but allows the outer (piston side) to move.

[aesmith]

Originally Posted by Bibio

what type of grease are you using?

For the brake pedal, MS3 moly grease. Was thinking possibly Vaseline, since the main purpose is to keep water out and there's no high speed or high temperature involved. Or, as I said, maybe just use oil and keep oiling it.

Regarding the calliper, I don't think the hydraulics are the issue. Doubtless it would be better for a rebuild but the piston can be pushed in relatively easily, and when releasing the brake pedal I can see the piston moving back a mm or so. The brake doesn't bind at all in use.

Similar the sliding pins, they're completely free moving when I check them individually. Someone at work suggested maybe something's bent and the two sliding pins aren't parallel, so that's something to check. I'll check whether it moves freely fully assembled but without the pads.

It seems to be the front that's the issue, when I press the pedal and watch the calliper it looks as if the back moves a little, but not the front. I'm starting to think the issue is that spring/shim thing that locates the front tabs on the pads. Although it clearly doesn't stop the outer pad moving.

i just used 240 grit sand paper and sanded the foot pedal shaft by about half a mm
the re-greased it and
wow no more problems
as i too greased it 3 times and it just locked up after a few weeks
so rub the shaft down only takes 30 seconds to sand it .

[Jayneflakes]

I have never had this issue with the brake pedal, but then I spray my bike with water dispersing spray after a wet ride. It takes about thirty seconds and keeps the rust gnome in check.

Luckily for me, a can of water dispersing spray costs a pound from our local cheap shop, the sort of cheap shop where you go in for a can of spray and come out carrying three cakes, a bag of roofing nails, a Ukrainian ex army oil can and a job lot of extra thick bleach!

For sliding bolts/pins only silicone grease should be used, it would also be fine to use on the pedal pivot, I use this http://www.ebay.co.uk/itm/Ford-BMW-C...item3f3f268b88

[Bibio]

Originally Posted by nutzboutbikes

For sliding bolts/pins only silicone grease should be used, it would also be fine to use on the pedal pivot, I use this http://www.ebay.co.uk/itm/Ford-BMW-C...item3f3f268b88

or RRG. dont matter as long as its safe on rubber.

on any external pins i prefer to use and its the only time i use copper grease on brakes especially in blind holes like those on curvy rear callipers. never use copper grease on the back of pads, in fact unless your brakes are squealing then you should never use any kind of grease on the back of pads and instead use shims.

Red rubber grease should not be as a general purpose grease, the sliding pin in most cases is metal on metal which is why silicon grease should be used.

Completely agree here Bibio, pad retaining pins should be dry with a dab of copper grease on the end, its also the only place I use copper grease.

I don't get caught in the rain very often, and I don't ride when there are salt/de-icing chemicals on the road (not when they're wet anyway). I've had good results using molybdenum disulphide in spray-on dry application. It's a high temp high pressure lubricant that doesn't attract dirt and seems to have no bad effects on rubber. I use it on all the sliding parts of brakes. It isn't resistant to brake fluid, but if you have a fluid leak, you need to fix it anyway.

[aesmith]

Originally Posted by Jayneflakes

I have never had this issue with the brake pedal, but then I spray my bike with water dispersing spray after a wet ride. It takes about thirty seconds and keeps the rust gnome in check.

My bike doesn't get that much love, it's an all year round commuter and when I arrive back home from a wet ride back from work the bike will just get parked as it is - unless there's something noticeably amiss of course.

Originally Posted by nutzboutbikes

Red rubber grease should not be as a general purpose grease, the sliding pin in most cases is metal on metal which is why silicon grease should be used.

Be aware that in some cases the sliding pins are sliding on rubber. This applies to all the front pins, and one pin on the rear. Anything that makes that rubber swell will cause issues. Having said that, you're recommending Silicone grease which is pretty much inert. I've generally used that for all brake work before I'd even heard of RRG.

Something else that I've used is stuff called "Turbo Gel", a synthetic grease containing teflon. It's similarly inert, and also very waterproof, but it's a bit expensive and not readily available except from marine suppliers.