Brake caliper faint gurgling sound after rebuild

I've done a rebuild of all the calipers on my KZ1000R2 with new pistons and seal kits, so they should seal up like spanking new.

After bleeding my front brakes I noticed a gurgling sound on my right front caliper as I pushed on the brake. After looking closer I could see it was leaking small amounts of fluid. What the heck :blink:
I took the caliper of the slider and looked closer and I could see that fluid was coming out of the dust cover on the piston. I couldn't believe this as all the seals and also the piston is brand new. I disconnected the hose and disassembled the caliper and took a look. It seemed that the end of the dust seal connected to the caliper itself might not have been seated correctly into the groove in the caliper. I removed everything and installed it once again.

After putting everything back together and bleeding the brakes once more, i can hear a very faint gurgling sound compared to the one before. But i see no brake fluid leaks, yet. I fear that the faint gurgle is telling me that somethig is wrong. Can anyone tell me if I have to take it apart again, or should i watch it until it starts leaking?

Also I have been using DOT 5.1 brake fluid, the Nissin Daytona master cylinder i have states "use only DOT 4 brake fluid from a sealed container", does this mean I should use DOT 4 instead? :blush:

Not sure on the sound, but DOT 5.1 will be just fine.

tommyboah wrote: ...It seemed that the end of the dust seal connected to the caliper itself might not have been seated correctly into the groove in the caliper...

That won't cause a leak, the dust seal is just that, it doesn't seal for fluid - even with the dust seal completely missing there shouldn't be a leak. What contains the brake fluid is the piston fluid seal, the rubber ring that goes around the piston and sits in a groove inside the caliper. Probably no way around going over the caliper again and make sure the fluid seal is positioned correctly and undamaged.

And yeah, like Koolaid says DOT 5.1 will work fine, DOT 3, 4 and 5.1 are compatible with each other, DOT 5 is not.

OnkelB wrote:

tommyboah wrote: ...It seemed that the end of the dust seal connected to the caliper itself might not have been seated correctly into the groove in the caliper...

That won't cause a leak, the dust seal is just that, it doesn't seal for fluid - even with the dust seal completely missing there shouldn't be a leak. What contains the brake fluid is the piston fluid seal, the rubber ring that goes around the piston and sits in a groove inside the caliper. Probably no way around going over the caliper again and make sure the fluid seal is positioned correctly and undamaged.

And yeah, like Koolaid says DOT 5.1 will work fine, DOT 3, 4 and 5.1 are compatible with each other, DOT 5 is not.

Ok, thanks. I will check under the dust seal for leakage, if there is a leak I will drain the fluid and go at it again keeping my attention on the seal ring inside the caliper.

I drained the caliper and took it apart again today. I noticed that there was some old residue in the groove behind the sealing ring in the caliper. I scratched that away with a flathead screw driver and put it all back together. No gurgling/squishing sound yet after bleeding. i think I might have pulled it off after the second time :woohoo: