Just ordered some +2 spieglers. I've never replaced lines before, any tips for bleeding them? Or is it just lots of extra 'cycles' to get the air out.
Having swapped both sets of lines + a couple of brake fluid replacements on my Vee, here are some thoughts & tips:
-Get yourself a good bleed/vacuum pump kit, like this Harbor Freight one: https://www.harborfreight.com/brake-...kit-69328.html
-Buy the big bottle (32 oz.) of store-brand DOT 4 brake fluid at Walmart. It's not expensive & you'll have more than enough. The front and rear brake systems together hold only a few oz. of fluid, so you'll have plenty to flush/bleed front brakes, rear brakes, and clutch (on DL1000).
-I was never able to get a solid, completely bubble-less flow coming out of the bleed screws. Not sure why. Maybe it was air leaking in around the bleed screw threads, when cracked open?
-So what I did instead was, I flushed the entire contents of the master cylinder through, 3-4 times per caliper.
-While doing the above, don't ever let the master cylinder run completely dry - you'll suck air into the lines.
-With new lines, I don't think it matters in what order you bleed the front calipers. The aftermarket line setups typically have a double-banjo at the master cylinder, so each caliper has its own line, therefore there's no "longest" line to flush first.
-To be extra-careful about getting any possible air out of the system - once you're pretty sure you've got all air out of the calipers, do the following:
--Squeeze the brake lever in (or push the pedal down, as appropriate) all the way and hold.
--Place a rag around the banjo bolt on the master cylinder.
--Crack the banjo open just a touch.
--Fluid will come out, hopefully the rag will catch it. Tighten the banjo back down, then release the brake lever.
--This should get rid of any bubbles hiding in the master cylinder banjo bolt.
-When done with all the above: secure the brake lever all the way in, and leave it that way overnight. Either place the master cylinder cover loosely, or leave the cover off & drape a rag over the cylinder (the idea is that you don't want random debris drifting into the master cylinder while it sits uncovered).
-By the next morning, any remaining air should have bubbled up and escaped. Screw the master cylinder lid back on, and you're good to go.
Hope this helps.