@$&*#@% Anti-Dive Brakes!

[Griffin]

The 1150 and 550 are equipped with Suzuki's PDF anti-dive system. I've changed brake fluid on both of them after the systems were bone dry. During bleeding, I didn't have any problems getting the air out. The brake levers both have a firm, linear response and the pistons are fully engaged with the levers about halfway to the throttle.

The GS700 has the older anti-dive design, commonly found on 1982-1983 vintage GSes. I rebuilt the front calipers on it last night, then proceeded to go through nearly a quart of brake fluid, feeding and bleeding out of all four ports, trying to get the air out. I only achieved moderate success in my endeavor.

The brake lever goes about 1/4 way through it's travel before any resistance is felt at all. The next half of lever travel feels spongy, but does actuate the calipers to full lock. Unfortunately, it takes so much travel, there is only about a half inch distance between the end of the lever and the grip. I like to use two fingers for braking, and leave the other two on the throttle. I can't do that now, because my two fingers on the throttle are pinched by the lever. The spongy feeling isn't very confidence-inspiring either. The system must've been well bled before, because although a bit spongy, it was far better than this.

Anyone with this anti-dive system on their bike have any suggestions, or special procedures they use for bleeding these things?

 

[Mr. Jiggles]

I still have the anti-dive units on my bike. I also had problems with sponginess until I changed over to steel braided brake lines. Are your lines still stock??

 

[Griffin]

I still have the anti-dive units on my bike. I also had problems with sponginess until I changed over to steel braided brake lines. Are your lines still stock??

yup. :?

 

[oldschoolGS]

there is a specific order to bleed in. If you don't have it:

1. left anti-dive
2. left caliper
3. right anti-dive
4. right caliper

This is per the factory manual.

One other suggestion- the anti-dive function is worthless on these bikes. All they do is rob pressure from the calipers with all their additional plumbing. I have had mine removed for 20 yrs. I use aftermarket springs to contol damping and braided steel lines run only to the calipers. This produces true 2 finger effective braking. Add an aftermarket fork brace and you have about as good a front end as you are gonna get without doing a complete swap.

good Luck, Ed.
1983 GS750ED


http://groups.msn.com/SuzukiGSGarage/gs750edbacktolife.msnw?action=ShowPhoto&PhotoID=3191

 

[Eliseo Monteverde]

Re: @$&*#@% Anti-Dive Brakes!

.... there is only about a half inch distance between the end of the lever and the grip.

In my Katana with anti dive I learnt to drive with only about 3/4" distance between the end of the lever and the grip.
Personally I do not want to do any mods, because I keep my bike stock.
...but sometimes I would like to change my mind. :lol:

 

[Griffin]

there is a specific order to bleed in. If you don't have it:

1. left anti-dive
2. left caliper
3. right anti-dive
4. right caliper

This is per the factory manual.

That's how I did it, but it was still mushy. I'll be trying again tomorrow.

One other suggestion- the anti-dive function is worthless on these bikes. All they do is rob pressure from the calipers with all their additional plumbing. I have had mine removed for 20 yrs. I use aftermarket springs to contol damping and braided steel lines run only to the calipers. This produces true 2 finger effective braking. Add an aftermarket fork brace and you have about as good a front end as you are gonna get without doing a complete swap.

good Luck, Ed.
1983 GS750ED

I've been thinking about disconnecting them and upgrading to steel lines. If I don't get them working well tomorrow, I might just do that.

The PDF system doesn't seem to help with front end dive any better than the older setup, but at least it doesn't seem to affect the braking function at all, and is easy to bleed.

 

[Griffin]

I got 'em bled as good as I think they're gonna get. The brake handle only moves back abotu 2/3 of the way to the handgrip, and I can keep my two fingers on it and lock 'em up. Still spongy though.

Now I know how Popeye got those forearms. He must've bled brakes for a Suzuki dealer int he early eighties. What a workout!

All I need is an anchor tatoo on my arm, and I got the Popeye look down.

 

[Joe Nardy]

I got 'em bled as good as I think they're gonna get. The brake handle only moves back abotu 2/3 of the way to the handgrip, and I can keep my two fingers on it and lock 'em up. Still spongy though.

Now I know how Popeye got those forearms. He must've bled brakes for a Suzuki dealer int he early eighties. What a workout!

All I need is an anchor tatoo on my arm, and I got the Popeye look down.

I removed my anti-dive lines years ago which helped the lever feel somewhat. Last year I installed stainless lines and the difference in the lever pull was so great that I had to adjust the brake light switch because I couldn't pull the lever far enough to activate it.

Joe

 

[Eliseo Monteverde]

All I need is an anchor tatoo on my arm, and I got the Popeye look down.

Maybe an spinach salad could help you,before bleed the brakes and the Anti Dive.

:lol: :lol: :lol:

 

[tfb]

I still have the antidive units on my Kat1100... might ditch them one day, but mine still seem to work OK and I have no complaints. APART FROM the blistering fact that, as many others have observed, they are indeed a pain to bleed. It's crazy to have to pump through gallons of brake fluid in the quest for that elusive air bubble, isn't it. :roll: And that's after following the correct bleeding procedures as per the manual, I might add.

So what I did last time was this: I got a length of inner-tube tyre rubber, and wrapped it around the brake lever/ handgrip, so that the brakes were pulled on nice and hard for a few hours. The idea (which I think I got from somewhere here on the GSResources) was that any small air bubbles in the system would dissolve under pressure into the surrounding brake fluid. Then, I quickly bled out the air-carrying fluid before the bubbles had a chance to re-form.

And the result? All I can say is -- whether the theory is right or not -- it worked! No more sponginess (I have braided lines on the bike), and no more symptoms or signs of air in the system.

Hope that helps,
Mike.

 

[Jethro]

Wow, I'm gonna have to try that method on my bike. The anti-dive units are a pain to bleed!