Bleeding the XJ750 Seca Front Brakes

I reference this often enough that it's probably past-time to turn it into a standalone thread.

What I do to bleed the system.
1. get a large syringe from a farm store and about a foot of vinyl tubing (you can also use a 2-stroke oil mixing syringe).

2. Cut 6" of tubing and attach that to the end of the syringe. Remove the Syringe plunger. You now have a funnel to fill the master cylinder with.

3. Break loose all four bleed fittings (be sure to put down cat litter or drip pans).

4. Tie the brake lever to the grip.

5. Fill the master cylinder and syringe.

6. Wait overnight (or at least a few hours)

7. You should now see brake fluid coming out. Close the bleeders, and untie the brake lever.

8. Bleed the brakes as normal, starting with the anti-dive bleeders, then the brake caliper bleeders. Remove the funnel.

9. You aren't done yet. There will still be some air in the system. The next step cures that, no matter what method you use to fill and bleed the system.

10. Use a vibratory sander (no sanding pad) and slowly run it along the brake lines, calipers, and distribution block from bottom to top. This will move any remaining air bubbles up into the master cylinder. Tap (or vibrate) the master cylinder to get the air bubbles to come out of the return hole. This process can also be done with a box-end wrench or other similar tool, and tapping the calipers and lines (it just takes longer).

11. Do one final bleed normally, just to be certain that the calipers are fully bled.

12. Use a flashlight to check the fuid level in the master cylinder. It should be below the fill neck. Unfortunately there is no dip-stick or sight glass on this master cylinder, so unless you empty it and measure out the fluid you will need to just eyeball it. If the fluid level is too high the brakes can hydrolock and not release.

 

Sander usage same principle to compact poured concrete with construction plant. Need to try that next time l bleed brakes.

 

Yep. Brings the air bubbles to the surface so they can pop.

 

I think step 10 requires sub-sections;

10.1 Video yourself using a sander on your bike
10.2 upload to Youtube, and post link

 

So I have had a little of my favorite brown liquid. Deleted two posts because I remembered this is a family-friendly forum.
We went a bit beyond the usual double-entendre.

It was good though. Should have been here to see it.

 

Funny.

 

Getting a little Brahms and Liszt with that brown liquid lol.

 

On trying get the front brakes bled on my Seca 750, to bleed the brakes I did the 12 state step process ad noted from k-moe and used a 2 stroke mixing syringe. For checking fluid level, I used a 12 gauge insulated wire as dip stick. still getting air after bleeding in the system and filling up almost two small fluid bottles also used a vacuum bleeder as well., Also, when pulling the brake lever there a suction or a slight plunging sound coming from MC. In doing MC rebuild, I used the original piston and seal since the new one that was from XJ forever kept binding up, even after soaking it in brake fluid overnight. Open to any ideas to get my brakes bled.

 

Curious, did you get the OEM or the aftermarket kit? My memory is getting faulty, but I'm pretty sure I got aftermarket first (no replacement spring), then most recently the OEM. The first one also kept binding on me and eventually fully failed leaving me with NO front brake mid-ride last year - whether due to a bound seal or bad original spring, I do not know. I just recently re-re-built with the OEM kit and it 'plunges' smooth as silk. Maybe Chacal can chime in, but I'm now a bit dubious of the aftermarket kit. Should have listened to my father - buy one, cry once.

 

The OEM kit is typically better than aftermarket Contact info@xj4ever.com

 

Installed the MC refill screw again and lost the air/ plunge sound, but still no brake level pressure. I did get the MC rebuild kit from xj4ever for 130.00 +- and the piston and spring later on. Thanks for the reply.

 

Are the brake lines the originals? Are the calipers rebuilt? How about the Anti-Dive?
Did you anneal the banjo washers, or use new?

 

I'm losing my marbles trying to get the 750 Seca front brakes bled.

I rebuilt the MC, calipers, and anti-dive units, so the system started empty.

I've tried @k-moe's method of tying the lever to the handle and leaving it overnight, nothing happens. Fluid doesn't go anywhere, fluid level in MC does not change. I've tried vacuum, no luck. Good old fashioned pump and twist, no luck.

I've gotten to the point where I disconnect the hard line at the MC and it just pumps air. How in the sweet fiddlers f%*& are you supposed to get that MC bled?

It almost feels like I must have something wrong - a clogged passage or backwards seal or something. The main output passage is clear and the two holes at the reservoir mount are clear. What am I missing???

 

I've gone through this twice in the last couple years. Last time, I wound up back-filling as much as I could from the bottom with the hardline cracked at the top of the master cylinder. Honestly having the forks apart made it easier though I don't know if I would do that just to get to the master cylinder.

Then the other methods of leaving the level tied overnight and whatnot were the finishing touches.

 

Aha!!! Now I understand the syringe holder thing! Thanks @Oblivion !!

I'm going to stop beating my head against the wall and order me up some syringes and more tubing.

 

Best wishes.

 

OK, I was able to back-fill the lines as discussed, but still no real progress.

It still seems as though it is not pulling any fluid from the reservoir. The MC pumps and I can bleed one or two times at a bleeder screw, then nothing. In fact, there is then a vacuum in the system. At this point shouldn't it be pulling fluid from the reservoir into the system to make up for the fluid that was bled out?

I've had the MC off several times and I don't think there are any blocked passages, but maybe I'm missing something.

That then leads me to think about the piston seals - could I have one on backwards that is preventing flow from the reservoir? Maybe a bad one? Again, I've had it on and off several times and everything seems correct.

@Oblivion, @k-moe, @hogfiddles, @chacal?? Anybody?? I'm at the end of my rope here.