1982 GS1000S Katana forks with the Anti-dive, leaking fork seals?

[roy826]

Time has come they are leaking at the seals and have never been into. The oil has been changed over the 40 years a few times and Suzuki was nice enough to add a drain hole to do that. Now that the seals are leaking I need to remove the forks from the bike which means the Anti-dive must be disconnected from the brake system. Another reason to not like this failed technology from the 80s. Added work for no gain. I have serviced dirt bike cartridge forks in the past so I am somewhat familar with fork work. I plan to order everything that is rubber inside the forks minus the Anti-dive part which I do not plan to take apart at this time. Any tips, tricks or watch out advice I need to know taking the forks apart and putting back together.

[Rich82GS750TZ]

Don't know if it's exactly the same, but there is a lot on the anti-dive fork system in this supplement for the '82 750 E and T (E had the anti-dive, T did not).

https://gsarchive.bwringer.com/mtsac/~cliff/storage/gs/Suzuki-gs750ET-SUPPLEMENT.pdf

If you use the search you should find many threads on the site that talk of buying or making a blanking plate w/ a channel that replaces the anti-dive unit.

[dorkburger]

I'm only familiar with the later PDF units, not the brake actuated anti dive. Other then the anti dive, they are old school damper rod forks. If you're familiar with cartridge forks, these should be pretty simple. Those with such things use an impact gun to loosen the damper rod bolt at the bottom of the fork. If not you will need something to hold the top of the damper rod while you loosen the bolt. Mine was a 19mm 12 point recess. I welded a 19mm bolt to a long rod, then held it with vise grips. Its awkward.

[roy826]

So I figured I would get a service manual like a Clymer to step me through this easier. Nope out of stock at Clymer and my local Suzuki dealer doesn't have a manual either for this 40 year old bike. Found one on ebay but for an incredible $149.99 amount and it was used not even new for that kind of money.

Guess I will tear into them blind, what could go wrong.

[roy826]

F0DDAF59-253A-4B4C-B0C7-FF5800AA264F.jpg
She is forkless! Just left the upper fairing attached and had plenty of room to work. I need to remove it soon to have it repaired around the signal mount holes but not this go around. For the curious I have it strapped down to the lift on the rear subframe. The jack stands with bar through engine mount it just in case a strap comes loose it will still be supported. No weight on them at the moment they are strictly insurance right now.

Parts ordered. Ordered all OEM seals, gaskets and orings and new seal retainer clips. Hope that is all I need once I tear into them in the upcoming week. Everything was available from Suzuki so I should have the parts by middle to end of next week.

[roy826]

DE600B97-585E-43FA-95D0-D7E47371D93E.jpg

one down one left to take apart. Not a bad job way easier than modern dirtbike forks. Made a tool for the damper rod removal out of an old spark plug wrench from some bike from the past taped to two long extensions with a 14 mm socket holding it all together. Worked great! Seal was a bear to get out. Everything cleaned up and awaiting new parts arrival. I did not take the anti dive stuff apart it'll be fine once I reattach it to brakes and bleed out good.

[roy826]

Well the fork job went smoothly they are like new. Unfortunately I managed to break the little plastic switch pin in the brake switch while having issue bleeding the 40 year old master cylinder out. No big deal I'll replace the little switch pin only one of the tiny little phillips screws that hold the pin cover in place decided to snap off in the threaded hole on the bottom of the master cylinder flush. I said several choice words once that happened. Now the fun part trying to drill a even tinier hole in a tiny screw what's left of it to get a tiny extractor bit in that. The girl is the gift that keeps on giving some days. Any advice or different approach to removing that tiny screw remainder, greatly appreciated. I am ordering the tiny parts I need tomorrow when dealership opens back up on tuesday.

It appears Suzuki no longer sells the entire front master cylinder for this bike so that is not an option or I would just do that.

[Rich82GS750TZ]

I’ve you don’t want to bother trying to extract that screw, they do make a switch integrated into a banjo bolt, you have to splice the wires into the harness or add your own connections. Just be sure to get the correct banjo size and pitch. Probably 10mm x 1.00. But be sure to be sure.

[salty_monk]

When you release that cover there is a spring and a ball bearing & a circuit board with some contacts on it....

Personally I would probably switch to the banjo bolt type. You could probably hide it at the joiner on the triple tree rather than have the wires sticking out at the master cylinder...

What I actually did was switch to an EX650 master cylinder with a microswitch.... get an adjustable lever then too. The parts on the clutch switch are exactly the same.

[roy826]

When you release that cover there is a spring and a ball bearing & a circuit board with some contacts on it....

Personally I would probably switch to the banjo bolt type. You could probably hide it at the joiner on the triple tree rather than have the wires sticking out at the master cylinder...

What I actually did was switch to an EX650 master cylinder with a microswitch.... get an adjustable lever then too. The parts on the clutch switch are exactly the same.

The Katana has clip on bars and the master cylinder has to contend with a downward slope so the top fill cap will still be level. So any master not gonna work on it. Plus it holds the mirror stalk on the backside bar clamp. The master cyl can be seen in the picture above in a earlier post of mine.

I managed to bugger up the hole removing the broken screw so I just re-tapped the hole to a slightly larger screw. Waiting on the internal switch pin and a new bolt/washer for the other hole. Once that all arrives this project will be put to bed.

[dorkburger]

The 1150 es.... has to be ES, not E, has a similarly shaped master cylinder. Possibly first generation GSXRs as well.