SM strut oil info needed
05-29-2016, 12:04 PM
#1
Thread Starter
SM strut oil info needed
I looked at SMs instructions but it doesnt tell you how much oil to put in the strut, or what kind of oil it is. I did some searches on rcu and didnt really find anything with the info I need. The struts are from a SM Large Viper, the stock oil is brown and smells like sewing machine oil but not sure what it is....It was real dirty and I am trying to get these struts to work so I took them apart and have cleaned them really well.... I thought I read some place brake fluid or transmission fluid works well...
The strut has a piston inside that simply slows the fluid moving from one side to the other and the manual states about 45 PSI for the mains but not sure how much to add for oil. Thanks
The strut has a piston inside that simply slows the fluid moving from one side to the other and the manual states about 45 PSI for the mains but not sure how much to add for oil. Thanks
05-29-2016, 01:05 PM
#4
Thread Starter
Thanks Joe!
Argyris, I dont suppose you can be a little more specific, how much of the strut did 8ml give compared to the over all volume. Did this give 1/4, 1/2 or 3/4 of the strut volume filled with fluid, if that makes since?
Argyris, I dont suppose you can be a little more specific, how much of the strut did 8ml give compared to the over all volume. Did this give 1/4, 1/2 or 3/4 of the strut volume filled with fluid, if that makes since?
05-29-2016, 01:34 PM
#5
Join Date: Jun 2006
Location: Gold Coast, Queensland, AUSTRALIA
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Fender,
If you follow the SM video instructions regarding the filling of the oleos and repeat a number of times to bleed all air out of the system - then leave the oleo filled completely with the oleo fully extended, but completely assembled with scissors link attached. I have been using a power boat, power steering fluid with a 15 rating.
I use 130lbs of pressure in my large SM Viper mains.
Cheers,
Jan
If you follow the SM video instructions regarding the filling of the oleos and repeat a number of times to bleed all air out of the system - then leave the oleo filled completely with the oleo fully extended, but completely assembled with scissors link attached. I have been using a power boat, power steering fluid with a 15 rating.
I use 130lbs of pressure in my large SM Viper mains.
Cheers,
Jan
05-29-2016, 02:35 PM
#6
8ml is near 3/4 and more.. of strut volume and works great on PC-21. PC-21 has the fill port on the top of the strut.So we fill until this port with the strut extended not compress..The total amount is even little more of this port.Because PC-21 is near 24 kilos empty we add 120 psi .If you want you can add lower psi.
Think of it as the amount of oil is to control the stroke of the suspension and that the amount of air pressure is the hardness of the spring.
Think of it as the amount of oil is to control the stroke of the suspension and that the amount of air pressure is the hardness of the spring.
Last edited by argyris; 05-29-2016 at 02:40 PM.
05-29-2016, 02:58 PM
#7
Thread Starter
Well sm instruction are miss leading, you cannot completely fill the strut because it will not compress. I managed to fix the gear which is great and I managed to figure out the system. I filled the strut and then compresses it to about half stroke. I then capped it and added 45psi per the sm viper instruction and boom! The hold the jet at about 3/4 stroke and with fuel the will probably go to 1/2 to a 1/4. I took the struts back off and relieved pressure and took the cap off and emptied the fluid into a tiny measuring cup. It was just under 10ml so I put the that amount back in the strut and removed all the air in the strut. Then I capped them and added 45psi to both, may have to increase to 50-60 psi but I don't think I will need 130.
