chancho196 Posted June 4, 2012 Report Share Posted June 4, 2012 I've now got a 1983 GSX750ESD in the garage for a rebuild, and possible cafe racer. It's rough as you like but, in my opinion, they're the best ones - the underdogs that need a bit of love. So anyway, the monoshock on this model has a remote, hydraulic preload adjuster - how cool is that back in '83? (Ohlins eat your heart out.) They also come with a remote damping adjuster. I took the spring off expecting the shock shaft to be rusted out, but it turned out to be perfect. Removed the seal head cover, knocked in the seal head and removed the circlip - no problems so far. Took out the shaft with piston and all looks good, but this shock is supposed to be pressurised with nitrogen. So... Where does it go? How is it put in there? Does it just share the same space as the oil (instead of a separate bladder), and how much oil does it require to work properly? Obviously the oil can't be filled to the top because it would lock up, but there doesn't seem to be much information online on how a gas shock works (when not fitted with a separate reservoir). It must work the same as your average Monroe gas shock on a car, but that doesn't help me with how this one is filled. Any ideas? Link to comment Share on other sites More sharing options...
cagimaha Posted June 4, 2012 Report Share Posted June 4, 2012 This is for a later GSXR1100 shock but they're not that different and the principles are the same. http://www.gixxer.com/forums/showthread.php?t=199645&highlight=gsxr1100+shock Hope this helps, Ben Link to comment Share on other sites More sharing options...
chancho196 Posted June 4, 2012 Author Report Share Posted June 4, 2012 Cheers Ben, much appreciated. It's a good write up, but that shock still uses a remote reservoir with separate bladder for the nitrogen. Link to comment Share on other sites More sharing options...
cagimaha Posted June 4, 2012 Report Share Posted June 4, 2012 Sorry, that'll teach me to actually read the original post before replying... Is there a valve on the adjuster (I'm assuming this is the highest point in the system) which would allow you to fill it with the oil (not sure on oil capacity, might be worth checking with someone like MCT or possibly getting your hands on an original Suzuki workshop manual) then pressurize the system? Link to comment Share on other sites More sharing options...
fran9r Posted June 5, 2012 Report Share Posted June 5, 2012 I seem to remember reading (somewhere, not sure where) someone fitted a push bike valve to a shock to pressurise it. I'd be very interested in anything you dig up. Link to comment Share on other sites More sharing options...
chancho196 Posted June 5, 2012 Author Report Share Posted June 5, 2012 That's what I'm wondering. If a Schrader was fitted to the bottom of the shock, would that be suitable for pressurising the unit, i.e. insert nitrogen directly in with the oil? I was sure somebody on here would've worked with shocks at some point. Most people with these old GSX's fit a modern equivalent, but I want to use the original if at all possible. Link to comment Share on other sites More sharing options...
Superdunc Posted June 5, 2012 Report Share Posted June 5, 2012 There are various ways of separating oil and gas. Forget your car Monroe/spaxgas dampers, they are totlly different. A pressurised gas damper normally runs about 200 psi, so fitting a schraider valve is pointless unless you have the kit to fill it. Is there a floating piston in the damper tube above the main piston? Link to comment Share on other sites More sharing options...
lorenzo Posted June 5, 2012 Report Share Posted June 5, 2012 If you've got a remote reservoir (which you don't, sorry), fitting a schaider valve to pressurise it all is a peice of piss, and scientific tests on team norths bros have proven that a nice screw in type one can withstand the pressure easily. Link to comment Share on other sites More sharing options...
Superdunc Posted June 5, 2012 Report Share Posted June 5, 2012 With standing the pressure is not the prolem with schrader valves, 20bar no worries. It's getting th gas into the damper at the required prssure thats the issue. Link to comment Share on other sites More sharing options...
chancho196 Posted June 5, 2012 Author Report Share Posted June 5, 2012 Cheers for the answers folks. Superdunc - thanks, that's what i wanted to know (car shocks). Here's some pics to explain it better than I can. Link to comment Share on other sites More sharing options...
chancho196 Posted June 6, 2012 Author Report Share Posted June 6, 2012 So, any ideas Superdunc? Where would the gas go? In fact, how are they filled from factory? Baffled.com Link to comment Share on other sites More sharing options...
tomekzxr Posted June 14, 2012 Report Share Posted June 14, 2012 Hi, I investigated the topic of rebuilding shocks becouse I'm going to do it myself. For old type shocks the soution is to fit car type shredder valve. near shock's mounting point on cylinder's side. In aluminium casting just drill and tap and use thread locker. On steel type there's usually thin wall so welding preffered. Car shredder valves are actually used on oem showa and kayaba shocks just covered under a lid. If there's no bladder nor piston dividing fluid and gas chambers, it's becouse it's so old less advanced model. It works just as forks-oli and gas are not separated. Nowadys the best racing forks are pressurised just as shocks, back then they didn't do it at all. As for the amount of oil I would use same much as You removed, asuming it did't loose any. If you're not able to say, then fully compressed shock must have some room left for compessed gas but in every situation piston must be covered in fluid and some more for safety. The gas chamber works as progressive spring so size determines what spring You get. You fill the gas ca.180-200psi. Link to comment Share on other sites More sharing options...
chancho196 Posted June 19, 2012 Author Report Share Posted June 19, 2012 Awesome! Thanks for that answer Tomekzxr, that's pretty much what I was hoping for. Link to comment Share on other sites More sharing options...
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