750 SECA Brake Bleeding Issue

I decided to redo the brakes and upgrade to SS lines. All kudo's to XJ4EVER, service and selection were great, as usual.
Swapped lines easily. If I were doing it again, I'd buy a few extra crush washers though, in case I decided to finish the job after dark and happened to drop one of those tiny things.
I'm a nurse so I had a 50 cc luer tipped piston syringe handy (works at least as well as a Mity-Vac) and the tip screws tightly onto the section of hose.
Great! Ready to go.
Now for the whine. I've spent too much of today bleeding the stupid things.
Put 1.5 litres of DoT 3 through the MC, still pulling bubbles and no back pressure at the lever.
Hmmm.
I went and found the MC/reservoir from my dear old donor bike. That's when I started to really get mad. The reservoir only holds about 15 cc's of brake fluid.
So, any one who decides to get new brake lines. Find a volunteer whose only job is to top off the reservoir.
I'm bringing home a 10 cc syringe for the next time.

 

Did you use the brake lever to "pump" the fluid through to the caliper? It is required to expel air from the master cylinder. It is common to see bubbles in the line if you are using a suction device to pull the brake fluid through.
I use a vacuum to start the fluid going then pump the rest through to get all the air out.

 

You have my sympathies, as I just went through something similar. In the end, I put 12 oz or so of fluid through my system because I had enough pressure to fully brake. After a few miles of riding, I'm ready to bleed again to rid those last few bubbles.

Read this to hear my similar story: http://xjbikes.com/Forums/viewtopic/t=42910.html

 

I've found if you fill the reservoir and open the bleed screws it will naturally bleed down into each callipre/anti-dive unit.
Then close them off and tap/wiggle/shake the brake lines and most of the air bubbles will rise to the top and into the reservoir, stop when you see no more bubbles(just moving the brake lever slightly in/out at the same time will allow the air to pass also)...

Then start the bleeding process.

Works for me!

 

I personally guarantee that if you follow these simple instructions; the whole Brake Bleeding process will take less than two hours. (I'm being generous.)

I did it in less than 90-minutes.
A 750 Max has no Dives.

Prep:
Remove the Bleeder Screws. Wrap them with three, tightly applied layers of Teflon Tape.
Make sure they are not clogged any free-flowing.

Use a Syringe and evacuate the Master Cylinder Reservoir.
After cleaning any residue; refill the reservoir.

Attach 10-feet of Clear Vinyl Hose to the Bleeder furthest away from the Master Cylinder.
The Hose MUST fit tightly without Air Leaks.

Attach Hose to Bleeder.
Open Bleeder.
Place the Hose to your lips and draw a Vacuum causing Fluid and any Air Bubbles to be expelled.

When the Fluid in the Hose gets to the 8 or 9 foot length, ...
CLOSE the Bleeder.
Remove the Hose and drain the Fluid in the Hose so your mouth remains fluid-free!

REATTACH Hose.
OPEN Bleeder.
Draw more Fluid and Bubbles into the Vinyl Hose until you remove all the AIR within the System.
:: You may have to drain the Hose 2 or 2 times ::

After you have successfully Bled the left side, ... repeat the process on the other side.

Air Bubbles MUST be expelled through the Bleed Screw.
That's why it's the BLEED SCREW.
Bubbles cannot be expelled through the Master Cylinder, ... unless the Main Hydraulic Seal is malfunctioning.

I did BOTH sides of my 750 Max in less than 90 minutes after removing both Calipers, removing both Caliper Pistons and installing New Caliper Seals.

If you can't hack maybe needing to spit-out a taste of Brake Fluid, ... buy a few more feet of Hose.

90 minutes after I put the rebuilt Calipers back-on the Bike, ...
Ii was DONE!

 

Has anybody tried to push the brake fluid up in the brake hoses thru the opened bleed screw before attaching the upper hose to the MC? THen most of the air would bleed at the upper connection next to the MC and you would have very minimal bleeding left the usual way (downwrads trhu the bleed screw.

I have a hand-drill operated pump that I could be using to try this procedure.

 

Used the MC from my donor bike, took it apart,burnished the internals with a Dremel. Everything seems to be tight as the proverbial drum.
The problem seems to be that I've emptied out the reservoir (repeatedly), even if it gets refilled every 10 - 15 cc's withdrawn.
Assume that you pull from the anti-dive bleeder first.
If we could push fluid up the lines, how would it move the brake cylinders?
About to start my 3rd litre of DoT3.
Still using the syringe, but I'll rewrap the bleeders with more teflon tape.
Thanks everybody for the input.

 

Sorry Quebecois59. Re-read your post. Did that at the cross tube and at the splitter. Then purged again.
Still don't get any back pressure, but when I open the bleeder and squeeze the handle, fluid comes out.
Must have an air thrombus (stationary) in there. Wish it'd turn into an embolism and "go with the flow".

 

Check to see that the MC is capable of developing Hydraulic Pressure.

Remove the Banjo Fitting at the MC.
Bleed the MC
PLUG the Outlet with a Bolt.
See if moving the Lever develops pressure.

 

Do you still have the original Master Cylinder behind the headlight that are standard on the 750 secas? Have you noticed that the highest point in the system isn't the reservoir, it's at the top of the master cylinder where the steel brake line comes in? And that the master cylinder is oriented vertically? If there is any air in system, it's going to travel to that highest point and get stuck there.

This is going to get messy. Remove the headlight and stuff a bunch of towels in there and see if you can bleed it at that connection. You pump the brake, crack open the fitting, then close it again. You are trying to give the master cylinder a chance to actually draw fluid from the reservoir (at the bottom of the master cylinder) once there is no air at the top.

Then proceed with normal bleeding procedures.

 

If you don't have any bolt that fits, the ones that hold caliper halves together fits in the banjo bolt holes (at least on my Seca900).

 

Thank you very much, Rick and Quebecois !
Read your posts and went out in the rain (Yamaha factory touring fairing which came off before any of this started, including the headlight).
Quebecois, you were right, there was a big air bubble.
And Rick, I couldn't find a bolt which had the same pitch, used my finger, (the back pressure helped to move the air out of the MC) and - voila, we have pressure at the lever.
I'm back to the jail for the weekend (work, not doing time), it's a hundred mile drive back to Rochester, but as a grey-haired grad student I'll take the work where I can find it.
Come Monday morning I'll get back on it. Thanks again, guys.

 

Not sure if I'm the one who talked about a big bubble, but i'm happy if I helped you in any way!

 

Hey Rick, reviving this thread here to ask you a question about this process you mentioned. I notice in your instructions you don't mention anything about depressing the brake lever at all? I've seen others mention this including the Haynes manual. Is this not necessary due to drawing the vacuum at the bleed screws?

 

Rick has not been on these forums since November of 2014.

 

Does anybody know how is he going?

 

Correct. When using a vacuum bleeder it is not necessary, though it may be helpful.

 

Just read about that in another thread. Sorry to hear.

Thank you for the help k-moe and others!