Not sure how seal grease would EVER travel up a brake line....
I'm not even sure how seal grease would get into the caliper brake fluid chamber if the pistons were coated with the stuff, as the seals would wipe most of it off....
And of the many calipers that i've had apart to clean the internals, i'm not sure how any matchstick, however it was shaped, would ever get into the entire seal groove area to remove the clag that i've experienced. With careful use of the dentists tool & thereafter with an old toothbrush, i've been able to clean up many a caliper, from my first Honda Four in 1977 to the 6 piston calipers I have on my FZR-R at present (I have some blue spots that i'm undecided whether to bolt them on to my FJ1200 or my FZR-R as both bikes have adequate modified braking atm).
As for the blue spot seals, these are not available via the R1 fiche but are obtainable from the XJR1300 page if my memory serves me right. But i've never had a problem removing the pistons on the Sumitomo monoblocs. I remove one side at a time, then reinstall only the pistons with the dust seals. Then I remove the other pair & remove the distortion seals. I then use a compressor to blow out all 4 equally, using a thin 12" metal ruler to keep things equal.
It's a pity that photobucket no longer works to my advantage, otherwise a picture would explain things.
Blue spot brake seals???
Hi Yamaexup, There is a backface to the pistons where grease could be pushed into the chamber, Nuggitt did not state that he put grease on just the sides of the piston.
Installing a greasy piston could cause blobs of grease to form on the rim of the backface.
The piston moving in and out pumps fluid both ways, it probably wont make it to the master cylinder, but it could easily make its way up a brake line and deposit itself there. These are brakes, why take the risk.
As an example, I worked for a TIG welder Co in Denmark, making stainless steel drainage pipes and normal steel products to EU Specs. Both work rooms were kept strictly separate, because fine mild steel particles in the air, would cause the stainless to corrode, just touching the stainless with a bare steel tool could also cause corrosion to SS and fast.
When buried underground this becomes a massive and expensive problem. Exactly the same physics applies to mixing aluminium and other metals.
The matchsticks worked for me and I can state it was not difficult. OGRI.
Installing a greasy piston could cause blobs of grease to form on the rim of the backface.
The piston moving in and out pumps fluid both ways, it probably wont make it to the master cylinder, but it could easily make its way up a brake line and deposit itself there. These are brakes, why take the risk.
As an example, I worked for a TIG welder Co in Denmark, making stainless steel drainage pipes and normal steel products to EU Specs. Both work rooms were kept strictly separate, because fine mild steel particles in the air, would cause the stainless to corrode, just touching the stainless with a bare steel tool could also cause corrosion to SS and fast.
When buried underground this becomes a massive and expensive problem. Exactly the same physics applies to mixing aluminium and other metals.
The matchsticks worked for me and I can state it was not difficult. OGRI.
Your last comment about the brakes binding more in one place than another sounds more like one of the discs is buckled.
If you have a black coloured white board marker pen, draw a wavey line on the outside surface of each of the front discs. Then spin the front wheel either on the road surface or with the trolley jack in place. This should show which disc is damaged & how badly.
Some disc pads don't move freely in the body of the caliper. Sometimes there's excessive paint where the disc pad touches the caliper. A simple dressing down with small file is enough to rectify this, together with a thin smear of copaslip
I'm still confused about how using a dentists tool will leave metal deposits within the caliper body when being used to remove old buildup of old brake fluid. These tools are stainless steel & i've yet to experience any damage to said tool that might damage the internals of an aluminium caliper body. I understand galvanic corrosion & seen it many a time where mild steel has interacted with ally. I had some of that with the FJ1200 exhaust studs. But not inside brake calipers from using a stainless dentists tool....
As for brake seal grease getting into a brake line, I could see that some 'MIGHT' get somewhere, but it would be suspended within the caliper at the utmost, not travel upwards towards the master cylinder...unless it has some form of buoyancy that is yet to be discovered....
If you have a black coloured white board marker pen, draw a wavey line on the outside surface of each of the front discs. Then spin the front wheel either on the road surface or with the trolley jack in place. This should show which disc is damaged & how badly.
Some disc pads don't move freely in the body of the caliper. Sometimes there's excessive paint where the disc pad touches the caliper. A simple dressing down with small file is enough to rectify this, together with a thin smear of copaslip
I'm still confused about how using a dentists tool will leave metal deposits within the caliper body when being used to remove old buildup of old brake fluid. These tools are stainless steel & i've yet to experience any damage to said tool that might damage the internals of an aluminium caliper body. I understand galvanic corrosion & seen it many a time where mild steel has interacted with ally. I had some of that with the FJ1200 exhaust studs. But not inside brake calipers from using a stainless dentists tool....
As for brake seal grease getting into a brake line, I could see that some 'MIGHT' get somewhere, but it would be suspended within the caliper at the utmost, not travel upwards towards the master cylinder...unless it has some form of buoyancy that is yet to be discovered....
Before reading these new replies. I was scratching my head quite a bit last night and then the penny dropped. It has to be the master cylinder on the way out. (10 points to stig)
I've just had a look in the bikes history book and I only changed the MC on the 11th April 2017. I got the seal kit from M&P. I was going to get an OEM from Yamaha but was told they have been discontinued.
I'm going to check the discs over like YAMAEXUP suggested but I wasn't getting any feeling of pulsing on the front brake lever at all. If they are by any chance warped or buckled I have a spare set of good discs to replace them with, but I'm sure there'ye not buckled/warped.
YAMAEXUP. You mention that excessive paint on the calipers can cause problems. These blue spots don't seem to have any paint, because they look like they are made from a cast metal material
Thanks for all your info lads. I'm off in my man cave now.
I've just had a look in the bikes history book and I only changed the MC on the 11th April 2017. I got the seal kit from M&P. I was going to get an OEM from Yamaha but was told they have been discontinued.
I'm going to check the discs over like YAMAEXUP suggested but I wasn't getting any feeling of pulsing on the front brake lever at all. If they are by any chance warped or buckled I have a spare set of good discs to replace them with, but I'm sure there'ye not buckled/warped.
YAMAEXUP. You mention that excessive paint on the calipers can cause problems. These blue spots don't seem to have any paint, because they look like they are made from a cast metal material
Thanks for all your info lads. I'm off in my man cave now.
Bit of advice. Buy a good bed and a good pair of shoes, because if you aren't in one you'll be in the other.
Well I've been in the cave all morning and I've decided its the MC that's causing the problem, so I've ordered a new kit which should be here on Tues/Weds.
I've got everything on the bench, reservoir, old piston out etc and I've cleaned it all up in preperation for when the new one arrives. Just a matter of putting it all back together and see how it goes. If that doesn't sort it I'll be back with another head itch.
I've got everything on the bench, reservoir, old piston out etc and I've cleaned it all up in preperation for when the new one arrives. Just a matter of putting it all back together and see how it goes. If that doesn't sort it I'll be back with another head itch.
Bit of advice. Buy a good bed and a good pair of shoes, because if you aren't in one you'll be in the other.
It's quite the paint on the leading & trailing edge of the backplate is what I meant, not the paint where the pistons press. If there's too much paint on those edges, dress them down a bit with a file so that the pads can move from side to side easily on the locating pins. A smear of copaslip helps on those surfaces.nuggitt wrote:YAMAEXUP. You mention that excessive paint on the calipers can cause problems. These blue spots don't seem to have any paint, because they look like they are made from a cast metal material
As for that washer in the new kit, that goes in place when everything else is in place just before you insert the circlip. Use a thin smear of red seal grease there as it will stop corrosion just before you fit the rubber boot.
Just been reading the responses again. Not sure why you should need to ensure this. The pistons aren't matched to calipers by tolerance. They're machined in there thousands.OGRI wrote:Make sure each piston goes back in the same hole it came out of
Still not sure how a stainless steel dentists tool is going to leave any particles of that tool in the caliper
And even more not sure how red seal grease is going to travel up brake lines when you operate the brake levers. I realise that the master cylinders are pumps but the fluid hardly moves except to take up wear of the brake pads
Hope it solves your problems Nuggett 
Hello Yamaexup, the post says to return the pistons and seals to their respective holes, as the seals wear to match too. In any case, it is good practice to return stuff where you found it, that way there is no discrepancy, as pistons can become out of round, scored etc. they are over 25yrs old now.
The cross contamination of dissimilar metals coming into contact with each other, was an example of factual experience, to flout those rules in that company was a sackable offense, when taken in conjuction with poking around inside a caliper with a sharp stainless tool, it goes against good practise. Nuggitt himself had already pondered this and came up with the BBQ skewers and toothpicks, because he obviously has empathy for his 30 yr old 140mph race bike. Alu aircraft use alu tools to fix them, there is a reason for that.
If you believe that fluid from 12 pistons does not travel up the brake lines, thats fine.
I googled blocked brake lines, it can be very common on old machines, the advice was to clear them out with an airline.
Where does the debris and blockages in brake lines come from, its deteriorating seals and anything else that gets in the system, including atmospheric water and RRG if you introduce it yourself, which gets pumped back and forth, blocking any restriction it is deposited in or near not just brakelines, caliper passages too, forming a goo and sometimes even crystals.
Red rubber grease RRG is made from vegetable oil with a red dye in it, thats why it doesn`t attack rubber like mineral grease.
Brake fluid is Polyglycol a hydraulic liquid lubricant, anti heat, anti boil and anti corrosion to a point.
RRG is only a lubricant and mild anti corrosion, it does not have the qualities of polyglycol brake fluid. They are not alike.
Its entirely the owners choice to mix the two within a hydraulic system, though I and a number of others would not do so.
OGRI.
Hello Yamaexup, the post says to return the pistons and seals to their respective holes, as the seals wear to match too. In any case, it is good practice to return stuff where you found it, that way there is no discrepancy, as pistons can become out of round, scored etc. they are over 25yrs old now.
The cross contamination of dissimilar metals coming into contact with each other, was an example of factual experience, to flout those rules in that company was a sackable offense, when taken in conjuction with poking around inside a caliper with a sharp stainless tool, it goes against good practise. Nuggitt himself had already pondered this and came up with the BBQ skewers and toothpicks, because he obviously has empathy for his 30 yr old 140mph race bike. Alu aircraft use alu tools to fix them, there is a reason for that.
If you believe that fluid from 12 pistons does not travel up the brake lines, thats fine.
I googled blocked brake lines, it can be very common on old machines, the advice was to clear them out with an airline.
Where does the debris and blockages in brake lines come from, its deteriorating seals and anything else that gets in the system, including atmospheric water and RRG if you introduce it yourself, which gets pumped back and forth, blocking any restriction it is deposited in or near not just brakelines, caliper passages too, forming a goo and sometimes even crystals.
Red rubber grease RRG is made from vegetable oil with a red dye in it, thats why it doesn`t attack rubber like mineral grease.
Brake fluid is Polyglycol a hydraulic liquid lubricant, anti heat, anti boil and anti corrosion to a point.
RRG is only a lubricant and mild anti corrosion, it does not have the qualities of polyglycol brake fluid. They are not alike.
Its entirely the owners choice to mix the two within a hydraulic system, though I and a number of others would not do so.
OGRI.
Better not tell Yamaha then...OGRI wrote:The cross contamination of dissimilar metals coming into contact with each other, was an example of factual experience, to flout those rules in that company was a sackable offense
The downpipes on the Exup are stainless steel & the Exup valve manifold is cast steel of some alloy. The two materials are welded together & if anything is going to have a problem in the environment where it is, then it'll be there....
Better tell Yamaha to stop including a sachet of the stuff with new brake caliper piston seals then....OGRI wrote:If you believe that fluid from 12 pistons does not travel up the brake lines, thats fine.
I googled blocked brake lines, it can be very common on old machines, the advice was to clear them out with an airline.
Where does the debris and blockages in brake lines come from, its deteriorating seals and anything else that gets in the system, including atmospheric water and RRG if you introduce it yourself, which gets pumped back and forth, blocking any restriction it is deposited in or near not just brakelines, caliper passages too, forming a goo and sometimes even crystals.
Red rubber grease RRG is made from vegetable oil with a red dye in it, thats why it doesn`t attack rubber like mineral grease.
Brake fluid is Polyglycol a hydraulic liquid lubricant, anti heat, anti boil and anti corrosion to a point.
RRG is only a lubricant and mild anti corrosion, it does not have the qualities of polyglycol brake fluid. They are not alike.
Its entirely the owners choice to mix the two within a hydraulic system, though I and a number of others would not do so.
OGRI.
Surely, if the system was bled on a regular basis, as per the workshop manual, then sludge & other contamination wouldn't be able to form.OGRI wrote:If you believe that fluid from 12 pistons does not travel up the brake lines, thats fine.
I googled blocked brake lines, it can be very common on old machines, the advice was to clear them out with an airline.
Where does the debris and blockages in brake lines come from, its deteriorating seals and anything else that gets in the system, including atmospheric water and RRG if you introduce it yourself, which gets pumped back and forth, blocking any restriction it is deposited in or near not just brakelines, caliper passages too, forming a goo and sometimes even crystals.
Red rubber grease RRG is made from vegetable oil with a red dye in it, thats why it doesn`t attack rubber like mineral grease.
Brake fluid is Polyglycol a hydraulic liquid lubricant, anti heat, anti boil and anti corrosion to a point.
RRG is only a lubricant and mild anti corrosion, it does not have the qualities of polyglycol brake fluid. They are not alike.
Its entirely the owners choice to mix the two within a hydraulic system, though I and a number of others would not do so.
OGRI.
I recently had a Yamaha FJ1200 completely apart & the calipers stripped to their component parts. There was sludge in behind the pistons but none in the brake lines. I don't believe that the ABS system on the bike had ever been bled in its 28 years TBH, considering the mess.
And i'm not suggesting that, when a piston seal is lubricated with seal grease, that it's shovelled in place with a spade. It only takes a smear of the stuff & excessive grease cleared away. It would be wrong to assume that even a DIY bike mechanic would smear seal grease onto all of the surfaces of a piston before it was reintroduced into its cavity. Where would be the reason for that? So how would red seal grease get into the brake lines, even momentarily, before the system was bled?
I'm just not understanding your reasoning as to why you think that brake fluid travels back & forth in large amounts through the hoses as & when the lever is pulled & released, except to take up the unmeasurable distance between the disc surface & the brake pad