Modern Vespa

I have a 2018 Vespa GTS 300 with about 7000 miles. The right brake lever feels perfectly fine before starting the engine, but about the time the ABS light goes out after starting, the right brake lever gets very stiff to operate. After squeezing the lever as hard as I can, the lever slowly starts to work again, and then returns to normal operation, and operates normally until the next time I start the engine.

Anybody else ever had a similar experience?

Sounds like there is air in the lines.

I had this problem on my 2018 GTS. One morning the rear brake lever just refused to move at all. Had to replace the ABS control system to fix it. Not cheap. This is the only problem I have ever had with this scooter.

I got this issue with my 2018 gts 300 this week. May I know what is the problem and fix??

Hells any comments for the fix??

does it feel ok with ignition off?
does it feel ok with ignition on?
does it feel ok with engine started?

In my case, no, no, no. It was just completely seized up.

I had he same problem with my 2020 GTS. It was the ABS pump. I called Piaggio and they had it replaced it under warranty even though the warranty had recently expired. My dealer, Vespa of Ft. Lauderdale, was great in handling the issue.

yeah abs.

and I've no doubt that the solutuon for bigloveben will also be replacing the abs.

I was asking because @HellsGrampa said theirs felt ok with the engine off (don't know if ignition on/off) so was pondering that bigloveben might be able to remove the fuse for the abs as a temp workaround until replacing the abs. (think this would also disable the speedo)

Hell's Grampa here, I was the originator of this string. A couple of weeks after my original post, I found that the front brake lever got "hard" immediately after the ASR light (I think, may have been the ABS light, not sure anymore) turned off. I found that if I squeezed the front lever as hard as I could, the lever would slowly release and return to normal operation until I shut off the bike, and the hard lever would return as soon as the ASR went out after the restart, and if I squeezed it hard, normal operation would return until the bike was shut off again. Anyhow, one day the problem went away, and hasn't returned since. I'm absolutely clueless what caused the problem and why the problem went away.

interesting ...

I had the exact situation with my 2020 GTS. Then one day the lever locked up, no matter how hard I squeezed, and would not work again with the bike running or not.

That is when I had it hauled to the dealer and they replaced the ABS unit. Very dangerous.

Hi Everyone,

Thanks for the replies. To me, the brake lever for rear stiffens up once engine on and ASR lights is off.

Brought it to Vespa Kuala Lumpur Setapak, had the sensor and speed wheel refitted and adjusted, but it was not the cause. Alex the mechanic had activated ABS jam break a couple of times till it works fine, but the problem return the next day.

till today, once the ASR lights are off when running, I have to squeeze the brake to have running normal after that. I feel it is dangerous though.

Just another update, I did the bleeding for brake fluids today, the problem still there but a lot better, I hope from continuos usage the it will be fine.

So indeed:
Need to change the ABS module. Which is effing expensive.
Or bypass the module only leaving the front abs working.

I started having the same problem with my 2018 Super Sport front brake at 12.000 km ODO.
Haven't ridden it for about 20 days, and then before even starting it (before even switching the key to ON), I noticed that front brake lever is so stiff to the point that it seemed like it's welded in place, no movement at all. I depressed it with both hands full power, and managed to move it, but it was still way too stiff than it should be normally. After next 2 days of riding, it came completely back as it should be. I even brake-tested the ABS on purpose while driving, and it worked perfectly normal. However, I haven't had any warning lights on the dash, ever.
Then I left it again for some 20-30 days just sitting in a garage, and the exactly same issue appeared again. No warning lights again.
From what I read in the comments on various threads, symptoms look like ABS control unit decided to say goodbye.
Since the price of the new unit is approx 800€ , can someone suggest what other potential causes to eliminate before buying a new ABS unit?
Does anyone know is it required to calibrate/program the new ABS unit using diagnostics tool after it's installed, or it's just plug&play?

I am wondering what is the connection of long time standstill and failure of abs pump internal valve…Because after I managed to restore normal brake operation for the first time, and after stand still again for 20 days, the same problem appeared again
If the ABS pump failed, it should be in failed state permanently, right?

The workshop manual says plug and play, pads not needed.

Which page please? I can't find it

There was a recall (maybe a few) with incorrectly galvanised materials in the brake system creating hydrogen gas. That might be causing a pressure buildup over time?

https://www.asphaltandrubber.com/recall/vespa-gts-300-hpe-gtv-brake-line-recall/
https://motorsportsnewswire.com/2019/12/09/piaggio-recall-of-certain-vespa-gtv-300-gts-300-and-vespa-gts-300-hpe-scooters/

to fair, I'm referring to the HPE workshop manual but I'm confident the process is the same on the pre-HPE.

detailed abs replacement instructions start at the bottom of page 280 in this: https://manuals.wotmeworry.org.uk/Vespa/GTS%20300i%20HPE/GTS300%20HPE%20E5%20Workshop%20Sei%20Giorni%201Q000844.pdf

Just an update again, after having the proper bleeding it was slightly better, and having spoken with another foreman, I followed his guidance to service , remove the brakes pads, take it apart and squeeze in the pistons and reassemble everything. and after that the problem is gone!! No need to change ABS unit.

I also solved the issue few days ago, at least for now…Dealer did the brake lines bleeding (he said that abs pump was not bled properly on last change), and the brake is not stiff anymore. Hopefully it remains like that.

so in these two replies directly above the abs unit was not the problem. meaning abs unit fails are even more rare than some in this thread fear. who'd a thunk it.

Hopefully bleeding solved the issue with stiff front brake, we shall see in due time if the issue appears again.