bleeding anti-dive forks

[crc1214]

I was reading through a thread here, and it mentioned to bleed the anti-dive forks when bleeding the calipers. How do you do this? Mine is a 1978 GS550E, and I assume it has the anti-dive forks on it, but I do not see how brake fluid can possibly be in my forks (no hoses leading into it)

If so, where is the screw located to bleed from? Also, do I bleed these just like the brakes (do I need to pump the brake lever, hold, and unscrew, then repeat), or is it a separate procedure?

Thanks,

Chad
Columbus, OH 1978 GS550E

[KennyJ]

I don't think you have anti-dive on your bike, this was a very distinct 80's product. The anti-dive unit is on the front of your forks and looks like a vertical cylinder between 3 and 5 inches tall.

I don't believe all were brake fluid activated...my 85 550E is action oriented (the dive of the forks). My FJ1100 is definitly brake actuated though.

Kenny

[Anonymous]

Late model 8-valve GS550's did have anti-dive forks and they were activated by the brake fluid pressure. They are very noticable devices onthe front of the fork leg as Kenny says and would have a short brake line running from the caliper to the anti-dive unit. They are just a valve that restricts the fork oil movement, stiffening up the forks when the brakes are applied. It is possible to simply remove the short brake pipe and disable them.

Tony

[QuaiChangKane]

The way to tell is if you have a rectangular block bolted to the bottom of your fork legs with a jumper hose between it and your brake caliper.

Alot of bikes had them in the early to mid-eighties, some even earlier.

It's a simple process to bleed them - you do it the same way you do your brakes. It's just like bleeding 4 calipers instead of two. The best way to do it is to turn your bars full lock to one side, and start on the opposite side. Start with the highest fitting first - if it's your caliper, then bleed the caliper then the anti-dive on one side, and then the caliper then anti-dive on the other side. Don't turn your bars to full-lock the other way when you go to work on the other side - the whole reason you're turning them in the first place is to make one side higher than the other so you're more likely to get more air out with less work (at least that's what the factory book says).

It's basically a small piston that gets pushed into the fork when you slam on the front brakes, limiting the flow of fork oil through the oil-stop valve at the bottom of your forks, increasing compression damping which will stiffen your forks and reduce the amount your front end will dive under hard braking. Theoretically....

Some like it, some don't, but mostly it's not a really noticeable benefit. It can also make your front brakes feel a little spongy, since you're losing a little of your braking effort by having to move that extra fluid around. All you have to do to bypass it is to remove the extra jumper hose, replace the banjo bolt on your caliper with a shorter bolt, and plug the anti-dive hose fitting with a shorter bolt.



-Q!