Removing brake pistons?

I have the same problem as the OP, my plan is to reassemble the front brakes and bleed the brakes to gain enough pressure to force the pistons out.
Can someone explain the bleeding process for an sv650?

Originally Posted by ehhsee

I have the same problem as the OP, my plan is to reassemble the front brakes and bleed the brakes to gain enough pressure to force the pistons out.
Can someone explain the bleeding process for an sv650?

Well, I've given a quick description above really. The only thing to add to that is what Tim said about putting a piece of wood between the pistons (off the caliper) to stop them popping out completely.

Bleed from the top to get all the air out, so squeeze air out of the junction hose and bleed master cylinder banjo before starting on the bleed nipple. The system needs some fluid in it before you can get pressure at the lever.

If the lines already have fluid then bleeding should be easier. Assuming you have no leaks in the system; get a spanner over the bleed nipple; cover the niple with a peice of hose connected to a bottle or container with fluid in it (so no air can come back up the system); pump the lever and hold; open nipple whilst squeezing lever to the bar; close nipple quickly; pump lever and repeat until you get a firm lever. Keep topping up the reservoir.

The pistons should be out after a few good pumps with some pressure at the lever.

There are more detailed instructions on the site if you use the search function. Also loads of stuff online. Its the same process for most hydraulic bikes really.

Basically, I drained all the fluid and took my calipers off to inspect everything, I later found out that the pistons were seized (all 4) so my plan is to reattach it all and then force them out.
"Squeeze air out of the junction hose and bleed master cylinder banjo" - Can you explain how to do that please? I'm really inexperienced with bikes...
All help is most appreciated, I'm working a late shift tomorrow so I'd like to get this done tomorrow morning if possible.

Originally Posted by ehhsee

Basically, I drained all the fluid and took my calipers off to inspect everything, I later found out that the pistons were seized (all 4) so my plan is to reattach it all and then force them out.
"Squeeze air out of the junction hose and bleed master cylinder banjo" - Can you explain how to do that please? I'm really inexperienced with bikes...
All help is most appreciated, I'm working a late shift tomorrow so I'd like to get this done tomorrow morning if possible.

Started an answer but will PM you instead.

[Sid Squid]

You've got the brake system apart now, so don't fuss about putting it fully back together, just connect one line from the master to a caliper, push the pistons out, then do the other caliper after.

Bleeding: Fill reservoir, open bleed a bit, pull lever and hold, close bleed, wait a few seconds and repeat.

Important bits:

1. Do wait a few seconds after closing the bleed before releasing the lever - particularly when the system is completely empty.
2. Don't release lever even a little bit when bleed is open - only when it's closed.
3. Don't let the reservoir empty out - you'll have to start all over again.
4. Don't waste money on silly 'easy bleeding' gizmos.

Originally Posted by Runako

That's a really good idea. Will add this to the 'practical book of motorycle repair tips'

JonGeorge, can you give more description of the condition of the pistons mate?

The caliper must have been getting really hot, as I put 200 psi on it and it still wouldn't budge, also put a grease gun and again wouldnt budge, luckily I know a few guys who break suzuki's and got a caliper yesterday evening for £20, so cheaper than bloody re building it.. I don't see how you could ever get that piston out

Well, that's actually a pretty god solution. Glad you got it sorted

[Fallout]

Originally Posted by Sid Squid

4. Don't waste money on silly 'easy bleeding' gizmos.

I'd like to point out I borrowed the one I used.

Also I looked all over for a bleed nipple for my MC but realised I don't have one. Apparently the process in this case is to:
1. Fill reservoir
2. Squeeze brake lever
3. Crack banjo at the MC for a split second (long enough to lose a bit of fluid)
4. Retighten
5. Repeat

Also I read some ridiculous thread which says:
1. Remove brake line at the MC
2. Cover MC brake line hole with your finger
3. Fill reservoir
4. Slowly pump lever which will push out air and fluid past your finger
5. When only fluid is coming out, whip your finger off and quickly thread in brake lines before all your fluid ****es out on the bike



Both these techniques seem like a good way to cover your bike with brake fluid. Is there a better way? (Besides the mighty Mityvac)

[Sid Squid]

Originally Posted by Fallout

Is there a better way?

Yes, bleeding it properly. Which means that you don't need to bleed the master cylinder, this also explains why the overwhelming majority of brake master cylinders don't have a bleed nipple, (like yours), it's simply not needed.

Originally Posted by Sid Squid

Yes, bleeding it properly. Which means that you don't need to bleed the master cylinder, this also explains why the overwhelming majority of brake master cylinders don't have a bleed nipple, (like yours), it's simply not needed.

I would say that bleeding through the nipple wasn't enough in my case. It was only when I tried the suggestion to bleed the MC banjo that I got fluid through to the MC. 15 minutes of frustration was ended in 1 minute. As soon as fluid started coming from the banjo, it meant there was fluid in the junction and MC.

You don't have to bleed the banjo until its pouring fluid. Just enough so that its not fizzing air. When the fluid starts to come through stop. All i needed was some rag or doubled up paper towel under the banjo, that should be enough. Close the banjo and then bleed normally.

This worked for me. From this point, including bleeding both calipers, it took 5-10 minutes.