fork oil capacity 750SC '82-83 question

[borissytch]

hi ,
i just realized that I put too much oil into my reassembled forks. I used '84 CB750SC manual before I realized that my '83 CB750SC might have different specs!!!
I think I put about 70 cc too much in each fork.
I haven't  put them back onto the bike yet.

Even if I try to pour some oil out of them I can't be sure of the exact amount of it in the forks.

Does anyone know why it is bad/dangerous? And what should I do in this situation? rebuild the forks again and buy new oil? that'd be expensive....

thanks for you advises,
alex

[TOOLS1]

Too much is better then too little. I would not worry about it.
TOOLS

[sgtslag]

Too much oil can cause the seals to blow out, but it depends on how much excess you have in them -- oil will not compress, so if too much is in there, something will be forced to give when the forks compress...

The solution is actually quite simple:  drain the fluid, and add the correct amount.  Pull the drain screws from the bottom of the tubes, and empty them into a used oil container.  Compress the fork tubes to ensure that all of the fluid is removed, then re-install the drain screws, and fill with the correct amount of fluid; compress them repeatedly, with the top caps off, to expel air from the system, then install the top caps, and the fork tubes in the triple tree.

Alternatively, just drain out 70cc of excess fork oil from each tube.  Hold the tube over a measuring cup, pull the drain screw out, carefully, then re-insert it as you near 70cc.  Either way, no need to tear the tubes apart, just to solve the fluid issue.

Fork Oil is expensive ($10-$15/quart), but Dexron (III-VI) ATF fluid is dirt cheap (around $3/quart).  Dexron ATF is supposedly around 8W, but it is hard to know for sure, without very expensive test equipment.  Not sure the performance gained by using Fork Oil of whatever weight is worth the extra cash, but that's up to each rider to decide.  Cheers!

[Piute]

         I enjoy saving
   The book says tranny fluids ,Myself put it in your CARS tranny,Fork oil..huile a fourche (ab-la ?)Heavy 20w Drag Specialties 8 bucks reg.price about the price of a 6 pack.that i wont be drinking cause I'm riding
          Theres a dry fill and a just drain and fill changed my seals and putting in 7.5oz.CLYMER book says 7-7.3 oz in chp.8 and 6.9-7.1 in chp.3 ,Thats CLYMER fo ya doesn't say amount dry fill..
 " All "my past bikes I end up at least 1oz over ,heavy loads and hard front brake breaker,hit a bump while applying front bottom out ? 

                               Just my couple bucks more advise,no credit

[borissytch]

Thanks guys!
after all I took a deep breath and just drained out the extra 70cc of oil into the measuring bottle.
Still haven't had time to reassemble the front end. I'll see how it works then. Hope it's all right. I am a small guy anyway - 150 lb  shouldn't be too heavy on the shocks.
I used the fork oil bought at the honda dealer. It is expensive indeed - about 18$ CAD per 0.9l
But I was told that ATF has ingredients that eat the rubber of the seals... though the service manual does say ATF and it's much cheaper.

[TOOLS1]

"I was told that ATF has ingredients that eat the rubber of the seals"
Somebody was giving, you a bunch of BS. Automatic transmissions are full of rubber seals.
TOOLS

[Piute]

                                                                   

                     VERY good point ,2+1 bonus point, - 1/2 for missed spelled word "bs"

                   That was the 1st thing I thought

[TOOLS1]

But it was big "BS".
TOOLS

[shinyribs]

I cant believe someone told you that ATF is hard on rubber! That was rotten. Like Tools said,rubber is used to seal tranny's too.

[borissytch]

good point. I never thought of it!

thanks!

[bwrk3]

hold on atf F for old fords will mess with the rubber it not the same kind but atf dex works the best

[rrgunslinger]

I just use fork oil. I figure that's why it's called fork oil. But not the expensive stuff. Mostly try to do what the service manual says.  However I see your points on the ATF but I still don't like guessing...

[Piute]

I just use reg.but heavy fork oil cost 8.50 a quart not sure were the high price stuff comes from ,8 bucks for what it is.Any how this Clymer 1969-1978 says
                                                                  K1-K2   6.9-7.1oz.(207-213cc)...
                                                                ..K3-K6,CB750A  5.3-5.4oz.(160-162cc)
I bought this for my 1977 F2 no listed on amount..have a F.S.M. of my own on the way