Ok, so I did my front brakes a few days ago. When I did them there was only one Dust Seal and Piston Seal in each caliper. I can see there are supposed to be 2. Are these critical to have in there, or can I survive with only one? This is the first times the brakes have been off my bike since I have had it, so obviously I'm not dead already.

 

how far do you want to push your luck?

if you have only one piston seal, and that goes, well, you get the picture.

 

yeah, doesnt sound good. but does that mean that only one of the pistons is reacting?

 

if you engage the brake lever, that means you are putting pressure on both pistons on both calipers. it is not one separate chamber per piston, the caliper is just one big chamber for 2 pots. thus, if just one seal on either caliper goes, your brake system is pretty much useless. even if you could use the fronts, stopping power will be greatly diminished from lack of fluid pressure not to mention the fluid will more than likely be all over the pads, rim, and rotors.

just imagine bleeding your brakes and how the lever feels when you pull back on it and you crack open the bleeder. mush.

 

Those seals are REALLY cheap. How do the existing ones look?

 

well, like i said, both only have one on them. we finished putting the pads on and got them on, i have not ridden the bike yet though. when i squeezed the brake lever it was mushy, and then proceeded to tighten up each squeeze. now its nice and tight. there was also no fluid on the pads at all when we took them off (the old ones). and I opened the reservoir cap on the right handlebar and it was still full and proceeded to almost overflow as we pushed the pistons back in. the pistons moved freely without the seals at then end without any fluid leak.

and just so we are sure we are talking about the same thing, they are the little round lithium battery looking things at the end of each piston.

i am more than likely going to order new ones just to be safe.

[IMG]local://upfiles/5310/F76DA3551C064421A3469ABC369B9911.gif[/IMG]

 

dude,

you should have both sets in the assembly.

piston seal (#2) is for the oil.

dust seal (#1) is for keeping any foreign matter away from piston seal. whoever had your bike before was too lazy to put the dust seals back in. dust seals keep things away that could harm the piston seal, like grime, dirt, other fluids, brake dust, etc. anything that could compromise the seal, eat it away, dry them out, or cause the seal to deteriorate prematurely.

i spin the wheel a few times as i pump the brake to get things seated.

as for dealing with integrated fluid reservoir, this is the reason i switched to a remote unit. less mess.

 

Just a quick question about dust seals, on my dirt bike I have these neoprene (I think) seal savers, wandering if it might be a good idea for a street bike. What do ya think?

 

i don't know what those are since i've been away from the dirtbike stuff for quite a long time now. you could always ask the manufacturer if it will work for street application.