I did my first brake fluid change the other day. I used a mightyvac pump and followed the instructions from a youtube video as follows: Used the vac to suck out all the fluid from both calipers. Added fluid to the reservoir and sucked the new fluid into the calipers until there was no bubbles coming through the bleeder. When I got done the front wheel was dragging and the brake lever soft, so I bled it again, releasing a few air bubbles until it ran all fluid, with no better results. I tied the brake lever closed for a day to bleed the master cylinder which did not help. When I pull in and release the brake lever, I get the spurt of fluid coming up in the reservoir. Does this mean the master cylinder is OK? Is there still air trapped in the master cylinder? Everything worked before I changed the fluid (dot 4 to dot 4). The brakes were not binding before the fluid change so I think the calipers are OK. There were some small little globs of something in the reservoir that I fished out before they got sucked into anything but I'm not sure where they came from. Could the blobs plug the return hole? Is there a way to check? Thanks in advance for any suggestions.

 

I just did my front brakes the other day. Did you check to make sure the bleeder valve was fully closed? Once it's closed give your brake lever a few pumps. You should feel pressure after you pump it a few times. If it's not feeling firm then you still have air somewhere in there.

 

Year and model?

Are you sure the old fluid was DOT 4?

You should not see anything except brake fluid in there, the mysterious stuff you saw could be from a deteriorating brake line, seal, or from mixing incompatible brake fluids. Whatever that stuff is, it could be blocking the fluid return port in the master cylinder.

I suggest you disassemble and rebuild the master cylinder, clean out the lines, disassemble the calipers, clean them and replace the seals.

 

Thanks for the replies.
The bike is a 05 CVO E-glide. I ended up having a friend come over and we drained the brake fluid, took the calipers off and blew air into the caliper and worked the pistons in and out, cleaning the pistons every time they were exposed. We used a piece of 1/2 in plywood to cushion the pistons as they expanded, holding two sets of pistons in and letting the other two get blown out, but not past the the seals. We sprayed WD 40 on the exposed surfaces until they were clean, pressed the pistons by hand back into the caliper body and did the other side. We did each side about 5-6 times until the pistons seemed really smooth.
When we added the brake fluid we pumped the brake lever as we sucked the fluid through the system with a mighty-vac. By the time we bled all the bubbles out the brake lever seemed pretty good and the front wheel had very little drag, so I'm thinking it's good to go. I'll check for bubbles after it sits for a bit.
When we added the brake fluid, we did see some more floaties: Not sure where they are coming from, but we sucked them out and it seems OK. I feel like I learned a lot about brake systems. Thanks.