Question about old losi shock cartridges....

[Brandon G]

Has anybody had one of these apart?

Are they rebuildable?

How many o-rings are inside?

I am assuming the inside top "cap" pops off, but I havent had much luck. Seems like I need to use breaking force to get them off, and I don't have many spares.....

I would rather rebuild before buying the later double o-ring version. Trying to keep period correct, you know.

[mrlexan]

The newer ones, the short length are supposed to be rebuildable, but are difficult to get apart. The older ones, the longer versions, were designed to be replaced as opposed to rebuildable.

[aconsola]

They are not really rebuildable. there is a spring and a rubber washer in there, part of the volume compensating system, I don;t recall how many o-rings though. If you are able to get them apart without destroying them you could put fresh o-rings in, but it would likely need to be glued back together after meticulous de-greasing.
I'll see if I still have any broken ones and take a pic of the internals.

[aconsola]

One advantage of the newer ones for a runner is that they are much shorter in stack height and can give more travel both up and down.

[highwayracer]

hello All,

The original losi shock cartridges were not designed to be rebuildable. When you cut one apart, you will find one flat large o-ring (never seen another kind like it), a plastic spacer that looks like an up side down top hat, and a large spring that fits over the smaller end of the spacer.

If you are having problems with the shock leaking, it's because they were designed to leak. The losi shock does not have a blader like most of the top mounted shocks (kyosho golds). When a shock is filled correctly, there needs to be a place for the fluid to go when the shock is compressed. Because of the losi shock design, the only way they could do this was to have the oil move into the bottom end of the cartridge. The spring was suppose to allow the flat o-ring to move up and down within the cartridge.

When I use to race, I figured out that the shocks needed a second o-ring. I lokes at many options including the regular o-ring (associated) , the flat o-ring from yokomo and other varieties. I decided to use losi o-rings. I cut open 4 cartridges so that I can add them to the 4 existing cartridges. Here's what you do.

1. Take a .05 mm allen wrench and insert it inot one of the 3 slots of the cartridge (top view)
2. Push the o-ring inside the cartridge to compress the spring.
3. Fold the new o-ring like a taco
4. Insert the "taco" through the shock shaft hole.
5. Remove the allen wrench and make sure that the o-ring sits flat inside the cartridge.

This will cure all of the leaks. Also, when you are cleaning the cartridge, it will hold a bunch of water. Make sure that you det all of the water/fluid out because the first few times you compress the shock, it will look like it's leaking.

Hope this information helps...

Regards,
Highwayracer

[highwayracer]

One more thinkg, there was a company called SRS or something that made a cartridge for the older shocks that used bottom loaded o-rings (like the old rc10 shocks). It was made out of a really hard white nylon.

Regards,
Highwayracer

[aconsola]

good info on the old carts, I never thought of addding another o-ring in there like that.

I have a set of the SRS units on my jrx-2 shelfer. They seem to work well and are shorter in height than the stock ones so you get a bit more travel out of the same shock shaft and body combo.

-Anthony

[mrlexan]

I want a set (of the SRS units)!

[highwayracer]

mrlexan....smile, I have an extra NIP set for you

I'd like to do a trade, but I have to get a list of the things I need for my next project.

Regards,
highwayracer

[mrlexan]

PM sent............. Oh and BTW, post some pics of that Optima of yours. I know both I and Erik want to see some details of the rear suspension.

[Brandon G]

"designed to leak"

Yeah no kidding. Back when we first started racing the JRX2, we converted over to the H arm on the rear and flipped the shocks upside down to reduce oil loss. This was long before we knew anything about unsprung weight. What do you expect we were only 14.

[GJW]

we always used a brand of oil called ozcharge (ozcharage electronics-barry putty was his name) any aussie guys remember him..it made the o-rings swell a bit and stopped the leaks in the catridges