Yamaha TRX850 Enthusiasts Forum

Hi. I'll start with a bit about me as i'm new to the site. I've had my TRX for about 4 years now. It's a daily comuter bike so it's not the prettyest thing. It's all stock accept for r1 bluespots 2-1 akra pipe and k+n filter.
It's a great little bike but is well overdue a service, which it'll be getting soon.
I'd like to rebuild the calipers but i've never worked with bluespots before. How do you take the pistons out? Do you just pull them out or do they need a really large torx bit to take the 'blue spots' out?
Does anyone have a link to refubishing these calipers?

first welcome to the site ...
first drain all the brake fluid out ,dont get any on the paint work ,take the caliper off and with a bit of air on the banjo the pistons will pop out ,mind your fingers ,dont mix the pistons up .the first seal you will see is the dust seal next in is the piston seal carefully prize these out you can get seal kits from Yamaha if the pistons are badly corroded you will have to replace them as when the piston goes back in the caliper when you fit new pads the corroded piston will wreck the seals and they will leak if you have never worked on brakes before get some help from someone who has ,,and if your not to confident about doing this type of work leave to a mechanic--- somone will be along shortly to add some more info ,,

Hi 666

Steve's about on the money there - although if you're careful you can probably get away without popping the pistons to clean it all up, just push them out far enough to get a toothbrush all the way round, clean the shite out and use a ribbon of old flannelette bedsheet (don't tell the missus) for a final wipe and polish. Only use brake fluid to clean it up as there's a chance any other type of oil might make the seal swell.

I say be careful cos I wasn't and ended up pushing too far and dumped brake fluid all over the place... I've heard that taking the 'spots' out is a no-no cos you can't get the seals, it's no big deal though cos you can get the pistons out from the inside, just a bit fiddly getting them back in - I managed it though so it can't be too difficult - can it?

If you do go for a re-seal I'd like to know how much the kit costs...

G

I believe bluespot seals are so expensive it is cheaper to buy another pair off e-bay every time they need overhauled. Not very environmentally friendly to have a small pile of bluespots in the corner of the garage, but simple economics....

Certainly TDM seals were about £75 when I rebuilt my calipers back in 2002. Its unlikely genuine yam seals for bluespots will be drastically cheaper than this; as mentioned, try to clean them up before resorting to seal replacement.

Oh yes....dont get any brake fluid in your eye while you're working on them

It hurts

Why do you need to dismantle the brakes? Is something wrong with'm

Why do you need to dismantle the brakes? Is something wrong with'm

They work but they're a bit grubby. I gave them a clean with a toothbrush and brake cleaner a couple of years ago - I only pushed the pistons out a little with the leaver though. I've had the bike about 4 years so it's due a good brake service. Gonna put some braided lines on too. Does anyone know if putting a r1 or Thunderace leaver and mastercylinder inproves the brakes further. The bluespots were on the bike when i got it, i recon it's got a standard trx leaver and mastercylinder.
I rode a Thunderace a couple of months ago and it's brakes were awesom. Is it the mastercylinder giving it some extra pinch? This t/ace is like new though, my trx is a little tiered - i'm sure braied lines will improve it anyway. Thoughts appreciated though.

666mph wrote:

Why do you need to dismantle the brakes? Is something wrong with'm

Is it the mastercylinder giving it some extra pinch? This t/ace is like new though, my trx is a little tiered - i'm sure braied lines will improve it anyway. Thoughts appreciated though.

It does, but you should really go for a radial master. That´s the shiate!

like this -

http://cgi.ebay.co.uk/Brembo-radial-bra ... dZViewItem

or this -

http://cgi.ebay.co.uk/Yamaha-2006-R6-R1 ... dZViewItem

So what's the difference? If i brought one is it just as simple as bolt it on and bleed it up? I guess it don't have to Yamaha if it's bolt on - do most new sports bikes come with radial master cylinders?

I don't know what the real difference between a 'radial' master and a conventional master is .. perhaps it's as simple as the direction of action of force against the master cylinder's piston...!

Having said that, I managed to find a Lucas radial on FluBuy recently and with the exception of arsing around trying to fit a brake light switch it was quite a simple job to install. Mine has a bleed nipple on the cylinder itself which I assumed had to be bled first, other than that it was exactly as it was for conventional lines.

Like a tw@t I can't remember what the ratio is, but I only need two fingers and a small squeeze to scare the sh!t out of myself!

G

Greg wrote:I don't know what the real difference between a 'radial' master and a conventional master is .. perhaps it's as simple as the direction of action of force against the master cylinder's piston...!
...

I think You're spot on there. And honestly, I can't understand what the benefits are. No reason why a radial should work better than a conventional master cylinder, or? My guess, it's a marketing hype, and that the master cylinders You buy as aftermarket might be built with better quality than OEM parts, and because of the hype, all aftermarket master cylinders are nowadays "radial". Any master cylinder with the correct (read: Your preference for feel vs force) diameter will be an improvement.

HansJ wrote:

Greg wrote:I don't know what the real difference between a 'radial' master and a conventional master is .. perhaps it's as simple as the direction of action of force against the master cylinder's piston...!
...

I think You're spot on there. And honestly, I can't understand what the benefits are. No reason why a radial should work better than a conventional master cylinder, or? My guess, it's a marketing hype, and that the master cylinders You buy as aftermarket might be built with better quality than OEM parts, and because of the hype, all aftermarket master cylinders are nowadays "radial". Any master cylinder with the correct (read: Your preference for feel vs force) diameter will be an improvement.

For once your dead wrong, hope you get to ride mine sometime and you´ll change your mind!

Hiya - I think Mans might have taken what I said out of context...

If you look at it in its most basic form, a radial MC does nothing different to a conventional cylinder - moving hydraulic fluid. The difference in braking effort is gained from the leverage derived from the hydraulic ratio. Ultimately, the braking effect achieved with the radial I put on is hugely different to the conventional cylinder it replaced, but who's to say that a 'decent' conventional cylinder with the same ratio couldn't have done an equally effective job!

I'm no fluid mechanic, but as I said before it will stop on a sixpence with very little two fingered effort now so smiles all round!

G

Greg I thought Hans was agreeing with you, and you're both right.

Killerwhale wrote:
For once your dead wrong, hope you get to ride mine sometime and you´ll change your mind!

read again, I don't say Your MC doesn't work better, which it probably does), but I can't understand what it has to do with radial or conventional design. And, braking is a subjective thing, some like feel, others power. Don't worry, we'll hopefully meet and get the opportunity to try each others bikes

martin young wrote:Greg I thought Hans was agreeing with you, and you're both right.

so did I