xj750rh bleeding Question

I replaced the oem brake lines with braided stainless type. I filled the lines from the anti-dive and caliper
bleeders with a syringe. My question is, When I am vibrating the lines with my sander, what position should the
brake lever be in ? Tied to the grip, or extended out ?

 

extended, then when you're done vibrating, just wiggle the lever a little. the air should be up by the banjo bolt and little pulls on the lever will help them come out

 

does this apply to the xj750 seca with the master cylinder down between the forks ?

 

xj750RH is a 1981 XJ750 Seca
R stands for Seca H is the year

 

My question was lever in or out when vibrating the air out of the hydraulic brake system
of an "81" xj750rh seca. I had the impression that Polock was referring to a bike with the lever
attached to an MC mounted on the handlebar. If I'm wrong forgive me. I remember Dave Hogfiddles
recommending filling the reservoir,tying the lever down and the brake fluid would drain down overnight.
this would indicate that there would be an unobstructed path for the fluid to drain down with the lever tied
to the grip. Would the same path the fluid took on its way down be open to air bubbles on the way up ?
Or, would the path for air to escape be open with the lever all the way out ? Or, perhaps it doesn't make
any difference and the air can escape through the reservoir whether the lever is in or out.

 

Yes sir, you know what the initials stand for. but, the question was on this model bike does the air
escape better with the lever in or out.

 

missed that you were op.

 

out, the line is open to the relief port and intake port
in, the piston is past the ports and the line is sealed
but does it matter, not much really
what matters is if the sander is on straight mode or orbital mode

 

When I replaced my brake lines, I used a syringe and tube from the bleed port to slowly force fluid up to the MC. I covered the MC with a rag or it will squirt all over.

However, I don't have anti-dive on my xj550. Would this method work for the OP's issue?

 

I started a big push on tues. 8/29 to solve this 750 seca brake problem. Got 2 new anti-dive "0" rings (thanks Len at xj4ever), New braided brake lines from Apex,
A spare used master cylinder from ebay, a couple of spare anti dive units from the junk box, and 2 more jugs of brake fluid. First I drained the fluid then pulled off
the old rubber lines, the left AD ( leaking air), the MC ( already rebuilt twice) and the calipers. I rebuilt the spare left AD, polishing the plunger bore, installing a new
"0" ring and remounted it.Then I remounted the calipers, installed the new brake lines, and wrapped the bleeder threads with teflon and screwed them in.
Now, everything is rebuilt to the splitter. I flushed and blew out the rigid tube and disassembled both master cylinders, the original and the ebay spare. Examining
all the parts, I chose the strongest spring and the best bore. I then pollished it out with felt disc dipped in polishing compound and with the dremel I shined that bore up
mirror bright. After cleaning the tiny return port with a strand from a mini wire brush, I flushed and blew the MC out and reassembled it, using the new seals ( from xj4ever)
and all the best parts.
The whole system was either new or rebuilt and time to add fluid. First I filled the reservoir with the syringe/funnel. then hooked up another syringe to the right AD bleeder
and a passive tube to the left AD bleeder into a jar. I opened both bleeders and pumped fluid from right to left, filling the lines with fluid and removing most of the air. I repeated
this about six times; vibrating the ADs, the calipers and the lines with my sander for several minutes in between pumping ( I clamped the syringe tube to the bleeder with a fuel
line clamp to keep it from blowing off the bleeder). After I could see no more bubbles coming out from the left bleeder, I closed it and pumped the syringe on the right till fluid
overflowed from the MC filler neck. I could now feel some resistance in the lever. I pumped it about a hundred times, held it in and let a few bubbles out of the left bleeder. Then
vibrated the splitter, rigid tube, MC and reservoir and pumped more fluid from the syringe on the right bleeder to bring the lever back. Repeating the sequence until the lever had enough
resistance to stop the front wheel. I used the syringe/funnel in reverse to suck the excess fluid from th filler neck and capped it. HOLY MOLEY I WAS DONE. Starting Tuesday I
was finished this morning. The front brakes actually work.
I started on 7/20 and finished today. Thanks to K-moe, Hogfiddles, Polock, Dad of seven, and Len from xj4ever as well as others. I could not have done this without you guys.
Also. the best advice was " Think like a bubble".

 

Wow! So happy for you! I could feel your pain and frustration the whole way through as I've been following along.
Glad you stuck with it and it finally worked out.

 

The master cylinder is between the forks. The front brakes on an xj750 seca are hard to get the air out of. First you have to make sure there aren't any leaks in any of the
brake lines, components etc. The only way to do that is to start at the bottom with the anti-dive device, rebuild it, the calipers next, and the lines and finally the master cylinder.
there are so many twists and turns in the design and pockets that trap air that it's easier to use air's tendency to rise in a liquid by pumping fluid from the lowest point, the anti-dive
device. I believe that getting the front brakes on an xj750 seca to work is a right of passage. Anyone who succeeds should get a tee shirt with " I got my xj750rh to stop" on the front.