How do these shocks work?

[TurnipJF 9192]

As those of you who frequent the build section will know, I am in the process of restoring a Sand Scorcher for @Grumpy pants. It has these shocks fitted:

I have taken them apart and given them a good cleaning but I'm struggling to get them filled with oil without causing a hydraulic lock. They don't have diaphragms or any sort of volume compensation mechanism, so unless I put in only a small amount of oil, they can hardly compress at all, as the piston shaft tries to take up space already occupied with uncompressible oil that has nowhere to go.

The pistons are solid brass items with no holes, so I was wondering if they are even supposed to be filled with oil, or if they are meant to be grease dampers?

If anybody has any experience with them, or thinks they have a suggestion as to how to get the best out of them, I am all ears!

[Juggular 4964]

That is curious...

Given the time period, maybe it wasn't an oil shock?  Just a spring guide mechanism?  (sorry, I'm not helping)

This problem seems to require older members' wisdom.  

 

[Nicadraus 6201]

I think a little amount of oil is what's needed to just lubricate the pistons. The damper is not supposed to be filled.

[Juls1 1661]

They are emulsion shocks the same as all the shocks that style available now. Ie: air is mixed in the oil. 

Keep topping them up until you get a little bit of end stroke resistance. Then your set to go. The airspace is required as with any shock, just in this case the air isn’t separated. Each time you use them the air gets mixed into the oil after a minute or two running. 

For a modern equivalent, 

Gmade XD come in piggyback with spring loaded floating piston as compensation, they also come as bladder type (as per usual Tamiya shock) and emulsion type. The gmade emulsion are a little easier to use as they have a bleed screw to let out excess oil.

gmade rsd are emulsion design too. 

As is Tamiya aeration dampers.

[ruebiracer 1046]

Can these dampers be quite new, and are the Tuning RC Channel Version for the SS Rere? Hard to tell from the photo, but I have the suspect, as the springs are also black, and design is very similar to the Tamiya shocks.

[Grumpy pants 4485]

1 hour ago, ruebiracer said:

Can these dampers be quite new, and are the Tuning RC Channel Version for the SS Rere? Hard to tell from the photo, but I have the suspect, as the springs are also black, and design is very similar to the Tamiya shocks.

I bought these shocks about 3 years ago, they where quite a popular hop up for the SRB’s for a while.

Definitely RC Channel about £40, I was looking for an alternative to the leaky Rere Sand Scorcher shocks.   

[ruebiracer 1046]

Ah, good to know! So the inner built up is probably quite similar to the Rere Shocks, but with a brass piston? I´ve also my Rere Sand scorcher shocks lying around, but they are quite oil tight. Problem is in my opinion, that some of the O-rings were not o.k. and 80% of the people overfilled them, which caused the leakage. I just found out, that the sealing / rod guide unit is the same design as for the Rere Hicap dampers, and so far I have not heard About people complaining leaks on them.

[TurnipJF 9192]

11 hours ago, Juls1 said:

They are emulsion shocks the same as all the shocks that style available now. Ie: air is mixed in the oil. 

Keep topping them up until you get a little bit of end stroke resistance. Then your set to go. The airspace is required as with any shock, just in this case the air isn’t separated. Each time you use them the air gets mixed into the oil after a minute or two running. 

Thanks for the advice. The shocks are now filled emulsion-style and are working well. 

[Static Age 65]

Look like RC channel shocks. I have a set on my Ranger, pretty good quality. I've had them a few years & no leaks. 

[Grumpy pants 4485]

Thanks for all the input and help on this topic in the last 24 hours 👍