[DIVINECHAOS1991]

So just got an 09 700 fi. Prev owner just put a new jug on it, due to not having programmer set correct...

So I've had to do a bit to it. Breaks all round and front wheel bearings. Since I got it the rear brakes didn't work right. New pads found a stuck slide. Replaced the rear calipers and it still feels odd. Rebuilt the master. Inside looked great mut had krud in it and the rubber was scored. Well ran a half bottle of dot 4 through both sides, and it still feels... Spongy sompaired to front.. any pointers?

 

[RedRocket]

Not uncommon to hear of breaking open the brake lines, replacing something and then ending up with spongy brakes. You most likely still have air in there as the brakes are pretty good brakes. Also make sure one of the pads isn’t having the pad “tab” get hung up on the caliper. But back to the air, a regular on here has recommended using c-clamps to hold the pad against the caliper, piston fully retracted and then bleed the brakes.

I haven’t had to do that but I’ve also never had to crack open the lines other than the bleed valve for changing fluid out, but that doesn’t really count.

 

[reogem]

I personally have never had an issue bleeding the brakes.
Do you have a helper to pull the lever while bleeding? If not a rubber band can be used to pull and hold the lever while the bleeder is opened and closed.

Avoid agitating the fluid excessively. This creates microscopic bubbles that are hard to get out. You may have to let the sit for a few hours for the bubble to dissipate.

These brakes can sometimes be gravity bled. Just open a bleeder allowing it to drain with a hose and jug attach. Keep the reservoir filled. This is useful in a case where there has been lots of bubbles introduced into the system.

As @RedRocket posted above,
Holding the caliper piston all the way in with a clamp and pad reduces the amount of fluid that needs to be pumped plus eliminates a chamber that can trap bubbles.

 

[DIVINECHAOS1991]

Not uncommon to hear of breaking open the brake lines, replacing something and then ending up with spongy brakes. You most likely still have air in there as the brakes are pretty good brakes. Also make sure one of the pads isn’t having the pad “tab” get hung up on the caliper. But back to the air, a regular on here has recommended using c-clamps to hold the pad against the caliper, piston fully retracted and then bleed the brakes.

I haven’t had to do that but I’ve also never had to crack open the lines other than the bleed valve for changing fluid out, but that doesn’t really count.

It had non op rear brakes to begin with. Replaced pads first. No help. So I checked master and smelt water. So I put new seals in it, which helped. So I replaced the rear calipers due to a stuck slide. Which helped. But they are spongy.. I'll try the c-clamp trick. Had no issue with the fronts. Those also had water. So I drained them and refilled and bled. No issues there. Just the rear.. the new calipers did come with a rubber seal washer and not a copper one though...

 

[Grizz2011]

Bleeding rear brakes? What's the trick?

Try removing the calipers and clamping the piston all the way down in it's bore until it's "bottomed out". Also hang/orientate the caliper with the bleeder in the up-most position so any trapped air will rise up to it. Also tape a wood spacer to your grip between the lever to keep from squeezing the lever too far. This will keep the master cylinder piston from over-travel out of its normal range and possibly damaging it.

After many attempts on my Grizzlies' rear brakes this is what finally worked for me.

 

[reogem]

................. So I checked master and smelt water.................

May have some corrosion issues in the lines and fittings.