Brake bleeding help

[jpaul]

I had a bear of a time getting the last bubble out of the mc on my 80 750E. I finally ended up taking my Mityvac and putting the narrow tip on the end, sticking that down in the hole at the bottom of the mc, and sucking out the bubble that was stuck in the corner there. I had to jiggle the brake lever a bit to get the tip down in as far as it could go, but once I did it took on squeeze of the handle and I saw the bubble moving up the hose of the Mityvac.

[salty_monk]

I put a hose on the bleeder & suck from the bottom down....

You might find clamping the lever back to the bar with a cable tie for a couple of days helps too.

Dan

[waterman]

I have used a long piece of nylon tubing and cycled the brake fluid back into the master cylinder when changing out old, crappy fluid. Used to do this on auto's when I didn't have any help. Simply get a piece of 1/4" nylon tubing roughly 10 feet long (for cars, motorcyles only need about 4 feet) and attach to bleeder and open bleeder and pump away. I collect the old, brown fluid and then just put the open end into the master cylinder and pump. This way your not worrying about fluid getting too low in master cylinder and sucking air.

For motorcyles, I find that once you get the bubbles out of the calipers, the line itself will often have a bubble near the outlet of the master cylinder, obviously this is the highest point where air will collect. While squeezing brake lever, loosen the banjo bolt at master cylinder. While fluid is coming out but before lever travels to grip, tighten bolt. This usually will firm up a lever. Unfortunately this leaves a mess of brake fluid to clean up from front end, but that is the "brakes".

[Baatfam]

So here was my solution. I removed the caliper just barely off the rotor, without disconnecting the brake line. Then I squeezed the brake lever once to make the pads come closer together, so that they actually wouldn't fit over the rotor anymore. Then I used a screwdriver to wedge the pads apart so that the gap was JUST BARELY wide enough to fit over the rotor, and reinstalled the caliper mounting bolts. I did this on both calipers, and now the brake lever is rock hard after about a half inch of travel.

DPage...you are my hero... I love ya, man....

I've had the same problem Joe had after rebuilding my calipers...
I tried everything in this thread...
MightyVacs, bench bleed, tied down lever, tapping, cracking the banjos, rebuilt master, ss lines...everything I could search up....

I just tried what you did and bingo...rock hard lever...almost no travel.
Perfect....
I see you're local, so when we meet...I owe a beer...or three....
Dang...I'm so happy, I'm gonna have one right now....

Thanks for starting this thread, Joe...

[jwhelan65]

Here is what I did on the brake system/caliper rebuild/restore for the 700E recently. The calipers were in about the same condition as the one pictured. The compressed air trick to pop out the pistons works well, the rear caliper can be tricky, but do-able.

Parts are optional to ones liking and preference. Just depends on the condition, but the piece of mind to know brakes are going to work when you need them. Suggest do it right if your mind even questions the condition of any part in this area.

First off, ordered new pads, OEM piston/seal kits, piston boots, pins, pin boots, pin bushings, springs, shims, indicator covers, bleeder valves, banjos, banjo bolts, crush washers, and new mounting bracket bolts for the front two. Also went with a new master cylinder.

The rear, new pads, OEM piston kit, piston boots, springs, bolts, indicator cover, shims, bleeder valve, banjo, banjo bolt, and crush washers. The pins, I turned some out of 17-4 SST, and the clips were SST, so reusable. New OEM master cylinder for the rear as well.

Scotchbrite pads to clean up the bore and seal groove, then polishing compound to get the bore pristine. Masked off the piston bore and seal groove, banjo crush washer seat, and bleeder valve threads. Media blasted the caliper bodies, cleaned, re-masked the bodies as mentioned before, but also used some o-rings to mask off the piston boot grooves. The rear halves were masked on the mating surfaces as well. Painted and baked them. Reassembled with DOT 3-4 on the piston seals, lubed the pins, and pretty sure the trick to installing the pistons is not to push the in until they bottom out. Gently work them in until the clearance is obtained when mounting them to the rotors.

Went with Russell SST lines, and just blocked off the anti-dives with new plates.


When bleeding the brakes, I usually pump them up to where the lever is tight, the open the bleeder valve to force the fluid through the system to remove air bubbles. The lever will bottom out to the handlebar, then continue holding the lever against the handlebar, and close off the bleeder valve. Release lever, pump up the system, and repeat until air bubbles have ceased. The lever has a considerable gap between the handlebar grip when pumped up and compressed when applying the brakes.

Thanks Tejas,

I printed this for reference, great information. The calipers I replaced mine with came off an 82 1100g and were in really good condition. Im going to tear them down again to make sure it is done right. The rear has not been touched so its coming apart. Thanks again man.

[Joe Nardy]

Joe, which bike is this on? Is it equipped with the chinzy Suzuki anti-dive valves?

If so, then there is a specific procedure to follow. I've perfected bleeding my 700 with the anti-dive valves so that they don't "spongify" (a new word!) the lever.

Brett,

I actually started this post months ago and it got resurrected recently (Kudos to Dpage for efficiently using the search function!). My anti-dive has been disconnected for years and I have braided stainless lines. The brakes are good now but I feel I still have too much lever travel. I'm going to try Dpage's tip right now.........

Thanks,
Joe

[tejasmud]

Thanks Tejas,

I printed this for reference, great information. The calipers I replaced mine with came off an 82 1100g and were in really good condition. Im going to tear them down again to make sure it is done right. The rear has not been touched so its coming apart. Thanks again man.

You are welcome, and not a problem, just my method. I'm sure others have gone a different route with no issues.

I have seen the pins on the front calipers lubed with anti seize when pulling calipers apart on a teardown, but tend to steer away from this practice given anti-sieze will dry out over time.

Another thing I was thinking when reading a thread on caliper pistons sticking after a rebuild was the mention of "pads wearing uneven and them being reused." If the pads are useable, mark the orientation they come off to keep them in the same direction. My preference is to just replace them. I know it must be written in the pages here somewhere, but not a bad thing to mention again.

[Baatfam]

I'm going to try Dpage's tip right now.........

Thanks,
Joe

Well? Did it work? It worked for me...

[Joe Nardy]

Wow! Thanks again Dpage. I fought this for hours back in September and never got the feel I wanted. Five minutes tonight and the brake lever is stronger than ever.

Joe