Rear brake

[Bazza123]

Hello all
One of the pistons has unsurprisingly seized in my standard rear calliper, so I’m going to sort that soon before the MoT. Does the calliper split in half for removal of the pistons, as I want to put new seals in? Otherwise, it’s looks like a bit of a job getting in there to clean everything and fit new seals.


The other thing I’d like to do is replace the rear brake hose - since it’s “only” the rear hose I’m not necessarily bothered if it’s braided or not, but can’t seem to source any standard hoses. Can anyone recommend something?


Thanks

[vinnyb]

  Hi Bazza
  welcome to the forum. If you get a used hose it will be at least 17 years old and buying a new Yamaha one will cost more than a braided hose. Hel hoses are very good and give forum members a discount (25% I think)
  As for the seized piston, have you tried clamping he free piston in place and pumping the pedal to see if that frees the seized one, it did with mine, it was slow but it moved. I didn't pop it all the way out I just smothered it red rubber grease and moved it in and out a few times to ease it a bit, I'll pop it out and sort it it properly when I replace the hose. Hope this helps

[74eldiablo]

Yes they split in 2.
As above just get a braided line it will be cheaper.

The seals were completely focced in mine and lots of oxidization and slightly pitted pistons.
Best bet is to spray with penetrating oil then whip it to anywhere with an air compressor and blow them out.

https://www.ebay.co.uk/itm/Rear-Caliper-Pressure-Oil-Seal-Dust-Seal-Set-yamaha-FZ600-1987-1989/162232541418?pageci=3476bc77-0070-428c-956a-44f4e4951d3b

Or spend £26 on genuine yamaha ones.


The ebay ones fitted perfect for me
New seals and lube up those pistons and seals.

Job done / job satifaction

[darrsi]

 


Don't buy a standard brake line, braided is the 100% way to go.


And unless the rear caliper is in a very bad way, as vinnyb says try and clamp the other piston and you should more than likely get the other one to budge.


I serviced all my calipers yesterday, and gave the whole bike a once over, and i will generally move the pistons out, clean everything with a toothbrush and brake cleaner spray (don't use anything else) then re-apply Red Rubber Grease to the outer part of the pistons and it keeps them all functioning perfectly. I'll also use a ball of steel wool to clean the pad pins and bolts.
Normally i'll pick a nice sunny day twice a year, before then straight after winter, but i just had a week off work and as the weather was reasonable yesterday i made good use of it.
Using brake cleaner, or WD40, clean the pivot of the rear brake foot lever too, as you'd be surprised how the dirty rain can clog it up eventually giving a spongy feeling if left unattended over time. I would hazard a guess something as simple as that is overlooked by a lot of people, but it can really make a difference.
These brakes are nothing short of brilliant if maintained properly, so look after them and they'll look after you.


Personally, i use SBS Ceramic pads on the rear these days, as they are a decent brand, but also staying away from organic pads keeps the dust down, which will in turn lower the chance of seizing again, although maintaining them is also the key to avoiding this too. I wouldn't use any harsher pads on the rear, because they'll just eat through the disc in no time if like me you ride in daily traffic a lot.
As for the front, i literally cannot speak highly enough about Galfer pads. Brilliant in every way performance wise, and even yesterday when i removed them from the calipers i was amazed at the way they looked almost spotless, with no crumbling or rust and with a quick spray of brake cleaner i barely had to do anything to them at all. And they are so gentle on the discs, yet take ages to wear down, i would never use any other brand now.     

[Gnasher]

SBS are the way to go front and rear, HS634 front, RQ570 rear.


If you split the caliper, which I'd only recommend in extreme cases.  You'll need to replace the sealing washer, this isn't available from Yamaha, luckily the same seal from the Suzuki GS500 fits.  Make sure you get all the oxidised material out of the main seal and dust seal rebates, any left in there will just start re-oxidising again and in a short time the piston will start to seize.  Be very careful when removing the oxidisation if you scratch the surfaces too deeply it will accelerate water ingress and oxidisation and that you fit the main seal the correct way round.         

[Bazza123]

Thanks for all the replies, very useful. I have a new seal for if I do split the caliper - is there enough space to remove the pistons without doing so? Looks pretty tight. New piston seals from Wemoto........ have read on here since ordering they are not always 100%.They look pretty uniform, are they meant to taper slightly? I have a set of vernier callipers so can check them with those.





 I’ve also seen those servicing ads where you can send the calipers off for about £60 so that could be an option but I’d rather do the work myself. A braided hose does sounds good, I presume I’ll need to remove the rear wheel to remove the hose clamp from the swing arm?


Sorry for all the questions!

[74eldiablo]

http://foc-u.co.uk/index.php?topic=25194.msg296837#msg296837

Regarding wemoto seals.


I personally found splitting the caliper an easy job, and it gave me a much better view of what the actual problem was (oxidization where the piston & dust seals sit) i popped out both pistons and used a wire brush wheel on the end of a drill to clean out the shit in the recess where the seals go, red rubber grease all seals and pistons push them back in and reassemble caliper job done.

As far as i can remember if your going to split the caliper the wheel has to come off the get to the caliper mounting bracket bolts off.
But you can fit a new hose without taking anything off.

Remember to bleed the inner bleed nipple 1st then the outer 2nd