Modern Vespa

Just sharing my findings regards the front brake on my GTS300 ABS.

I was disappointed with the front brake on the my new 300 (2500 miles now), it felt almost wooden ! I tried roughing the pads up, cleaning the disc with brake cleaner, and bleeding it …. but it still wasn't as I thought it should be. It just had no bite, so I have fitted EBC sintered HH pads, this was an immediate improvement.

I also struggled to get the lever to "feel hard and not spongy" (probably a technical term for this !), I moaned to myself that when it was PDI'd at the dealers that the brakes weren't bled properly, but I couldn't get them any better even after a couple of tries, and I got no air out of the system ! So as a last resort I tried an old trick I have used on my sports bikes before, pulled both brake levers on as hard as I could and put a cable tie round them to hold the brakes hard on over night ……. bingo, next morning levers feel great Much more bite in the brakes now.

I am back in love with the GTS again !

I'm definitely trying this tonight! I have also been unhappy with the brakes on my GTS. No real bite. The dealer has offered to look at them, just need to take it in, but the service manage also mentioned the "bite" was not real impressive. He recommended different pads, which I was planning on, although spending $150 or so on such an expensive scooter is a bit frustrating.

Why do you think this will help? What does it accomplish? It's too easy not to try, but??? I think I'll just use my griplock on the front lever overnight? Any reason to do both at the same time?

Hi gregbenner

The pads are cheap, I only paid around £9 for the front set delivered from Ebay, and only took about 10 minutes to fit. Regards why this works … I'm not too sure ? whether the fact that it sits under pressure and this helps force the air upwards I don't know. All I know is that it does work because its helped me out on several occasions. Just make sure that your brakes levers are pulled hard on and cable tie them up, next morning, a couple of pumps and you should feel a marked difference. Let me know how you get on ?

Tony

Fenner,

You may be brilliant! I always like nice stiff brake levers.
Do you think this will also work on my 2007 Suzuki Burman
400AN?

Bob Copeland

Not an expert Bob

Just know what has worked for me, give it a go m8.

Tony

It's a good technique to keep up one's sleeve - but it only works in certain circumstances. This is when very small quantities of air are trapped in pockets - typically at connections. These can be very hard to remove by conventional bleeding, though a vacuum bleed or reverse bleed often helps.

By compressing the brake levers, any air trapped is hugely reduced in volume, so reducing the surface tension where it is in contact with the brake line wall, and often breaking it away completely. It can then slowly travel upwards unimpeded, and will gather at the base of the master cylinder valve (firmly closed while under compression). As soon as the compression is lifted, and the piston moves back to open the valve, the air will escape out into the master cylinder reservoir and be free from the brake line itself.

Thx jimc, that makes some sense. The pads are inexpensive, but with ABS I don't feel like installing them myself, and the labor adds up. Would be nice to have good, responsive brakes, with spending any more $, if possible. I have both levers zip tied now, should know in the am

gregbenner, the pads are real easy to swap, no different to non ABS.

[quote="FENNER.gregbenner, the pads are real easy to swap, no different to non ABS.[/quote]

I suspect you are correct for a Vespa, but both my BMW and Tiger (with ABS) had wiring and sensors going to the calipers. Likely a piece of cake for most, but for me, easy to screw up (believe me, I know).

I suspect in the future someone will post a utube showing that these wires/sensors either don't exist on a Vespa, or don't need to be touched? Until then, I don't want to....

Will test the newly scrunched brakes this afternoon.

After taking mine apart, FENNER is correct. As far as the calipers themselves, really no difference.

The front ABS sensor and connecting wire are attached to the shock mount. The receiving sensor, the ABS sensing pin wheel, is attached to the front rotor.

On the rear wheel the ABS sensor with removable wire are connected to the outside surface of the swing arm. Again, the sensing pin wheel is connected to the wheel itself. The caliper is mounted on the opposite side of the wheel just as previous models. After reassembly, check your manual for the procedure to recalibrate the ASR. Pretty simple.

I also used the EBC sintered HH pads. Pads obviously have more bite, but nothing extreme. Enough to give you more confidence in your braking ability. Must say it did take a little more time to seat them into the rotors. Attached a pretty good video explaining the difference between certain types of pads. Towards the end shows a decent method of preparing and setting in the pad and rotor.

Fun project. Sure you wouldn’t have any problems if you’ve changed brake pads in the past.

Floridian, many thanks! I have changed pads many times over the years, although not since I broke my leg in 2011 (it is finally healed after three surgeries, but getting down on knees is tougher now). However, with your explanation and video I think I will try it. I put the EBC HH pads on my Victory XCountry, and really liked them.

Just tried the brakes after zip tying the pads for 24 hours. Definitely seems a bit better. Actually able to engage the ABS. With new pads, I think I'll be super happy with the brakes. Now if only the mileage (range) was better. Oh well, the scooter is so terrific I can live with 100 mile/tank range, and perhaps with more miles it will improve as well.

Thanks for all the ideas/help!

Just a follow up. I now have the EBC on both front and rear. Difference is quite noticeable The brakes now work like I expected from a new scooter.. As others have noted, I can actuate the ABS relatively easily, great immediate bite.

Had the same issue on GTS 300 SuperSport HPE 2019. Spongy brakes. Zip the brake overnight and come firmly again.

Chasing a recall on Piaggio.

I agree. They should recall - this could be a huge safety issue!

I definitely recommend a cheap brake bleed kit. Harbor freight has them for very little. Lots of bikes I have worked on have the sponginess cured through a combination of brake bleed and letting them sit under pressure. One of the most cathartic mechanic feelings is that first little "SSSSSSSSSS ppfff oooom" from a system under pressure with a brake bleeder kit on it after it's sat for a while.

Can you please detail a bit what is SSSSpffffooom?

Actually It didn't cured 100%, just more firm than spongy. I dind't let it 24h, just. I will try again tonight to see improvements...