Front calipers

[garrett]

Since it broke 50 degrees here today, I figured it was time to dust off the bikes and address any immediate issues. 

I had noticed a little last Fall that the front brakes were dragging a little, but with a few quick squeezes of the lever it would release.

While taking the bike off the center stand today, it would not roll back at all.  So I took the calipers off, removed the pads and sprayed some PB on the pistons to loosen them up.  They appeared to be frozen pretty good.  I was able to push them back, slip pads in and back on to the rotor.  Put everything back and and drove around the driveway a little bit - still seems to be sticking quite a bit. 

The other issue that I assume it directly related to this, is the lack of feel in the brake lever.  Not much pull back on it - feels pretty dead.  That goes along with the calipers seizing up I assume. 

Question is - do I try and fix the calipers on the bike or just order new ones?  Wasn't sure how much work was going to be involved in these calipers. 

Anything else?

Thanks in advance.

Garrett

[Mustang]

they can be saved by diassembly and cleaning
pop the pistons out without marring them (use the hydraulic force of the brake lever )
then scotch brite them and clean all the road and brake dust off
reassemble , and you are usually good to go
this is also a prime time to flush out the lines and replace the brake fluid.

[nickjtc]

this is also a prime time to flush out the lines and replace the brake fluid.

Should be done every two years anyway??

[NeilD]

more often than not its the dust seal (the outer one) that has gone hard  or swollen and hangs up the piston... just done the front on the Bonneville (pretty much same caliper)... also check the slider still 'slides' freely as they can get stuck... im sure there is a thread on here as rebuilding my tiger ones became an annual job when used through nasty weather... 

[Sin_Tiger]

If you're going to that much effort is worth changing the seals. As Neil says the slider pins and rubbers collect crap if they're not a perfect seal. The bits are not daft prices either. If you've still got the rubber hoses, changing them for metal reinforced is a very rewarding investment.

[garrett]

I was thinking I'd swap the brake lines to stainless.  I did that last year with my GS.  Stock lines have held up quite well, but it's easy and cheap enough. 

I'll pull them off and start disassembling tomorrow.  I've had good luck getting items from Bike Bandit in the past. 

Thanks for the suggestions.

[garrett]

Finally got around to pulling them off with the help of some good weather. 

Slider pin on one of the calipers was a little nasty, but sanded down slightly to get it looking better. 

The caliper pistons don't look that bad, but worth taking off and cleaning up.  Had some issues with not getting enough pressure to get pistons to push out.  Got side tracked with other bike items (found a crack in the right rotor) and other odds and ends. Need to get my shocks off now and sent to Sasquatch too - along with the Beemer. 

[Sin_Tiger]

There should be some grease inside the slider pin boots, use something that resists drying out and hardening. I use stuff that is used inside auto CV joints as it shouldn't attack the rubber.

The poisons should be free enough to move out using just a hand bicycle tyre pump. If not tye seals need replacement, they do swell, this is presuming the poisons are good. If that's good but they won't move on the bike then it's either time to overhaul tye master cylinder and or the hoses, they have been known to delaminate internally which can cause restriction.

None of this is uncommon on bikes this age.

[garrett]

Thanks.  I've used Bike Bandit in the past for some OEM items.  $41 for a seal kit per caliper.  Any better options? 

[ram33]

Thanks.  I've used Bike Bandit in the past for some OEM items.  $41 for a seal kit per caliper.  Any better options?

when i changed my seals i just measured the pistons (27mm i think) and found a set of seals the same size (for honda i think) all fitted and worked fine for about £3.25 (about $4.79)
like these
http://www.ebay.co.uk/itm/27mm-caliper-piston-seal-kit-fits-most-bikes-but-not-boot-type-piston-/360900835139?pt=UK_Motorcycle_Parts_13&hash=item54075db743

[Sin_Tiger]

  those calipers were fitted to quite a few Japanese bikes and probably still are. I'm convinced they are also the same on the front of Thruxton 900's and even on the rear of my 2014 Trophy SE but I haven't gotten around to verifying that yet. You can even get stainless steel pistons for them.

[Nick Calne]

I remember Triumph seal kits being very expensive  wherever you look, so a matching one from another supplier looks a good idea.

[ssevy]

I rebuilt my front and rear caliper last summer, and the seal kits from Triumph were $41 for a two piston set. I was able to use a wire brush wheel to clean up some the pistons, and as I recall, I may have had to replace one or two of the pistons themselves, as they were pitted too badly to be used? In any case, I used compressed air to pop them out, reinserting the first one which popped out just a bit back into the bore and then holding it in place with an open end wrench turned sideways as I applied more air and popped the other one out. I used the bleeder screw hole to apply the air, with a gently screwed bolt in the banjo bolt hole to prevent the air from leaking out. With a rag wrapped around the caliper to prevent the piston from flying out and damaging itself or me, I then used quick short bursts of air until the pistons came out.
I then cleaned and wire brushed the caliper body itself, and blew it all out.
The most important thing, however, is get some red rubber grease for the new piston seals, and lube them well before you put the pistons back in. This grease is specific to this job, and won't contaminate the brake fluid. The pistons will slide in smoothly, and the caliper action will be so much better when you are through. I got a small tin of the grease on ebay, and that is probably a lifetime's supply.
If you do happen to find the seals at a Honda dealer for cheap, how about posting the year and model for the rest of us?

[ram33]

i used Honda CB 750 F2N 1992-1995 Front Brake Caliper Piston Seals but i think most bikes with same size pistons will be fine
http://www.ebay.co.uk/itm/Honda-CB-750-F2N-1992-1995-Front-Brake-Caliper-Piston-Seals-/140893033836?ssPageName=ADME:L:OC:GB:3160

[Sin_Tiger]

Confirm as Ram said 27mm dia piston.