Modern Vespa

Yes, I did do a search and read all the posts on bleeding brakes on a BV 350 but nothing there helped.

2013 BV 350 non ABS but has a proportioning valve for back brake.

Rear caliper was frozen so I replaced it along with the banjo bolt and crush washers.

Been trying the pump, hold, bleed, repeat method but not getting anywhere. I am getting new fluid out and looks like no air but brake lever still goes right to handle bar.

Tried the reverse method of pushing brake fluid up from the rear caliper. I cannot get the syringe to move and push fluid up.

I next went to the proportioning valve and getting nothing out of the bleed nipple on that.

Suggestions?

Pressure bleeder? https://www.motiveproducts.com

The only way I do my cars now. Haven't tried it yet on the scoot. Source a spare reservoir cap and drill and tap for fitting.

I'll be watching with interst. Unfortunately cha I n of events left me in the same spot last fall and it's my next project. Did purchase a pump, so we'll see where that goes...

Failing that, wanna start a support group?

What bleeder did you buy?

What I find puzzling is the I can push brake fluid up from caliper???

BVBM group? BV Brake Misery?

I can't recall right now. I think its buried behind my replacement storm windows, my current project. It's not a major brand....

Now I have an incentive to have a go...either to have something to share, or to have a cry with you...

UPDATE:

I was able to bleed the rear brake using the pump and bleed method but I raised the caliper up and blocked with wood shims. See pic.

I got fluid out of the proportioning valve finally after the rear caliper bleed. I did do a couple calibrated taps with a NIST certified hammer. But I'm not sure if that was it or that I really opened the bleed nipple.

I had an issue with the rear brake on my 07 GTS. The lever action was squishy and really not getting any pressure.

I replaced the master cylinder last year thinking this was the problem and bled about a pint of brake fluid through it to no avail.

I wound up replacing the rear caliper and shoes, bleeding the system again, and then tied off the rear brake lever to apply pressure for a few days. Now I've got really solid rear braking again.

Yes, I had tried that before moving the caliper up high but still had a soft lever. After I did the bleed as noted above, I still tywrapped the brake lever overnight and did have some additional improvement.

Finally got my front brakes done and solid. No luck yet with the rear-still squishy, removed and elevated caliper, getting no bubbles with pumping.

Trying push method seemed to work, but getting some leakage, I think past the threads, despite being taped. Messy, and to date ineffective.

What year is your BV, Barry? I have in my notes that my '17 doesn't have a proportioning valve since ABS was added, but now can't seem to find that info. I guess I could go after more plastic and look for it, but resistant to go down that rabbit hole.

As my lovely assistant isn't always available or eager, I think a vacuum pump is in my future. It seems the Mitey Vac is the gold standard, but wondering if it's truly superior to the myriad other choices out there?

I have the Harbor Freight clone. It works well enough, though it helps to use a small hose clamp on the tubing at the brake bleeder.
https://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-63391.html

Thanks! Curious about what hose clamp you use. Of my bag of metal screw clamps collected over the years, my smallest didn't work, and the hardware store's answer was bigger than mine! I've had fairly good luck with the smallest zip ties....

Wondering too how to know when to quit. Not pulling any air after 50 cc of fluid? I threatened at one point to just get the family sized bottle of fluid and having at it.

If you get a MityVac, ensure you get the model that can pressurise as well as suck fluid. Makes reverse bleeding a doddle.

I found a couple of these pinch-type clamps at a local hardware store. For 1/4 or 5/16 inch, I believe.

They probably have them at my ACE store. Love supporting the place, but man, help isn't like it used to be. One of their clerks a while back was reeking of alcohol..... They've got some good people too...just not always easy to get them.

Maybe I should copy your photo....

I also use the Mighty Vac to do ALL brakes on any vehicle. The problem was having to stop to empty out the small reservoir bottle. The fix- get a pint or quart mason jar and plastic lid ( the black lids are leakproof) these from grocery store. Now get some 1/4" natural rubber tubing ( you will only need 8-10" or less) but it comes 10 ft at home improvement store. Also buy 10 ft of 1/4" nylon or plastic hose, and small tube of silicon sealer- also at same store. Drill or whittle two holes in the plastic lid an inch or so apart from each other. Cut one piece of natural tubing 2", and one piece 4". Force these through the holes in the lid leaving only 1" sticking out the top. Seal around the tubing w/ silicon. Let dry overnight. Hook your vac unit to the short hose sticking out of the lid with 4ft of nylon hose. Hook 4-6 ft of nylon hose to the other hose that has longer rubber hose sticking down in the jar. Now you have a larger reservoir. Just keep master cyl full and pump up vacuum unit and bleed away at the fitting. Hope this helps.