V7 II (ABS) - Rear Brake Not Pressurizing

[Dirk_S]

Since getting the bike back together, the past 30 miles have been going well EXCEPT I still can’t get the rear brakes to pressurize after a few attempts of bleeding and priming. If I pump the foot lever multiple times fast enough, I do build up pressure, but it quickly loosens up. During the first few pumps, I hear air movement in the lines to/from the ABS module. So, I have no rear brake.

I initially used a syringe to prime the line up via the caliper bleed port. Then I proceeded to bleed… and bleed… and bleed, via the reservoir—Pump, pump, pump > lever depressed > crack the bleed 1/4 and close back up quickly > repeat > fill reservoir as needed. No progress, and I feel I’ve done it enough times by now…

I’ve read that brakes fitted with ABS can hold more air and require more bleeding, and I see the ABS module sits in-line with or possibly higher than the reservoir. I also wonder if perhaps during the engine removal or installation—or while the frame sat outside during the 3 months it took me to rebuild—if the ABS module or it’s lines might’ve been damaged.

I checked all the nuts—everything’s tight. I figured my next step is to spray some soapy water to check for leaks. Anything else I can do to troubleshoot? I have GuzziDiag, and I know there was some ABS support added in, but I’m not completely sure what all it can check.

No alarm/light, so I reckon the module itself isn’t the problem.

[Vagrant]

The only way to get the air out is to remove the caliber, get it higher than the ABS unit then bleed.

[Air-Cooled]

Yes, that caliper is a down-low


html url generator

[Dirk_S]

Yes, that caliper is a down-low


html url generator

Yeah, I learned previously with my Honda CX500 that when bleeding it’s best to turn those calipers so the nipples are facing upward, but I did that, and am still not gaining pressure. Maybe I’m just not doing it right. I’ll try some more.

The only way to get the air out is to remove the caliber, get it higher than the ABS unit then bleed.

I hadn’t thought about that, mainly because I never had to do it before. Guess that means bringing the caliper around to the other side so all the hosing can stretch up. I’m assuming the lines also should be elevated, but the ones going in and out of the module are rigid.

[guzzisteve]

The only way to get the air out is to remove the caliber, get it higher than the ABS unit then bleed.

THIS and sometimes you have to feed it through so line is strait. To do that maybe wheel out or stuff moved. It does bleed through the pump with key off. Don't forget to put a wrench between pads.
I was doing alot of this so I bought a canister for air compressor line. Worth every penny.
The holes are smaller than they used to be.

[Dirk_S]

And we have brakes! Elevated the caliper and within a few pumps the air was out of the system. Easy peasy; thank gawd it wasn’t a leak or module issue.

Funny that Guzzi doesn’t mention removing the rear caliper for bleeding/purging.

Much appreciated, Vagrant, Air-Cooled, and Guzzisteve!