Prefered fill and bleed method on new rebuild front brake system

I fucking hate brake fluid.

I raise the handlebar a bit (to clear the limiting lug if present) and rotate it forward and orient the master cylinder so the lever end is higher than the banjo end. Or on the side stand with bars to the left. You might still rotate the bar to get the right angle but maybe not so extreme so the fluid is more stable.

Add brake fluid. Start manipulating the lever a bit. I end up almost slapping at it with the end of my fingers. I know this sounds weird. Just make sure you are getting some movement to move the piston over the bleed hole. Pretty soon a bubble will come up and out the bleed hole under the "hood". Then more will come up. They will get bigger and more often. Once it starts, it gets very encouraging, especially when a big bubble comes up. "Oh man, that was a good one!"

I can get a firm to firm-ish lever without ever cracking a bleeder. Then I do final bleeds on each side to finish off.

It can take a while on some bikes, but on others it started happening pretty soon and I started getting lever feel fairly soon.

I alternate between the small tap/slap movements with an occasional full pull. The tap/slap helps release the air up into the bleed hole it seems. Like tapping a brake line to help air bubbles up to the master.

People will scoff and laugh. It works for me, and I'm only fucking around with brake fluid at the calipers and wheels once, at the end.

If/when you get stuck, give it a shot. A beer and/or whiskey in the other hand is nice. Some music. Maybe a race on the shop TV. I've spent worse, longer times fucking around with bleeding than this.

Did I mention...

I FUCKING HATE BRAKE FLUID

 

Sarah will come down to the shop and ask, "what are you doing?". Maybe she heard some loud cursing or something.

"Bleeding brakes."

She turns around and leaves with out saying a word.

 

I don't know if this will work on thee fifth gen or not. I hate working on my bike. So a friend who claims to be a heavy duty mechanic, says that isn't much different from a car really. Besides, I do have the complete service manual in print. And we were doing a complete rebuild of the braking system, braided lines and all. Well, that did not work out. So I took it to a real bike mechanic. Then Bob's your uncle.

Then later, I chained the chain and sprockets. That front gear was just packed with crap and grease, After cleaning in up really good, and putting it all together, I had no clutch for whatever reason. Immediately before this everything was hokie dokie. I thought some how I got air into the clutch's system. I tried cleaning out the reservoir as best I could, then tried to bleed that system. I never did get any resistance on the clutch lever in the slightest. I tried anything and everything. Then I remembered the best way to do things is to take it to a real motorcycle mechanic. They got that going lickity split. Then I was a happy camper. A smile on my face until I had to deal with Honda and my brand new Gold Wing. Another story.

I did drink a lot through these procedures though so it was expensive. Soon as my cast comes off, I am going to ride bioth these bikes like a raped ape. In 5 days, 4 hours and 25 minutes.

 

md's bike is de-linked. It has a reasonable and logical front brake system on it.

 

Well there ya go. That will screw anyone's mind up something awful. I mean Reasonable and logical in this day and age. Pft!

 

I saw a thing on YT where a "massage gun" (sure) was used to agitate the front brake lever rapidly and it coughs all the small air bubbles out into the open master. I've done something like that when I have removed and refitted a master without draining the lines below and it works well (but without the "massage gun").

 

in some d ifficult cases, injecting fluid into the lowest bleed nipple with a syringe (non-linked) might out and up tne last small air bubbles//ive dcone that in 1 or 2 difficult bleeds or soft brake lever///tapping gently on the brake hoses after a new fill may free up small bubbles///i sometimes remove and hold the front mc as high as the line will allow, tapping gently on lines keeping it pointed up///another mini-bleed after the first ride can be helpful//

 

I think this was just talked about over at VFRD before the doors closed? All I've been doing for hydraulics work as of late is reverse bleeding with a $10 100ML syringe. Haven't broke out the MightyVac in some time. Even fluid changes. 1 syringe to pull crud from master, 2nd syringe full of fresh DOT4 down at whatever bleeder pushing in new fluid. Keep pulling out crud at master until everything appearing looks fresh. Close up and ride.

 

how much of a rebuild we talking? just soft parts? The last reverse bleed from dry job I did was a 5th gen clutch master last year. Reverse bleeding firmed up immediately. Sure you don't have a small weep somewhere? Crush washers all good? Check every caliper piston.

I remember chasing a clutch lever that wouldn't firm up years ago many bikes past. Wasted an afternoon with a MightyVac on a slave cylinder that was pitted and weeped ever so slightly.

 

Yours are de-linked? I can't speak to a bleed in that situation. I have done completely empty front circuit for Hurricane kit installs. I don't recall any issue regaining lever pressure. I wasn't reverse bleeding then either. Smething uniquely challenging about your de-link setup? Hose jumper loop trapping air?

 

Some people might consider placing a rag or towel on painted surfaces nearby (e.g tank or fairing) just in case ... minding that the hydraulic fluid can be used as paint stripper. At least so it was when I changed brake fluids some time ago.

 

I did a full on brake rebuild because I had dragging front brakes. Rebuilt both front calipers, twice. repllaced the stock 25+ year old lines with new braided. Rebuilt the master. And delinked.
After all of that work the front was still dragging.

I think that the previous owner had used non-silicone grease to lube the caliper guide rubber. And by doing so, they swelled and were not allowing the caliper to compleatly release. After cleaning those rubber guides and using a proper silicone based grease, the brakes are now releasing as they should. I had planned on ordering a set of new ones, but have not had issues since the clean-up.