My rear shock absorber exploded/burst spilling hydraulic fluid everywhere! My question is this, my L405 has a rear shocker with an extra external reservoir whereas the equivalent sport L494 does not! Why is that? What does the extra capacity do?
The electrical plugs on the top are identical and if I put a spare L494 Sport shocker in the boot and plug in the electrical socket there is no fault to display on the dashboard!

Anyone cast any light on this situation please? 🫶

Is the extra capacity a heat management solution? The extra thermal mass of the added fluid can more fluid movement through the valves without too much heat build up? First time FFRR owner

It's nothing to do with heat.

The external accumulator is used to hold more fluid to support the large variance of wheel travel that the L405 has (ie. when it's in extended mode).

Hope this helps  Kev

2014 L405 RR Vogue SE 4.4 SDV8 in Corris Grey
2010 L320 RRS HSE 3.0 TDV6 in Stornoway Grey

@knwatkins:

Clearly a knowledgeable and correct answer, and so very logical after a moments’ thought, isn’t it?

The general helpfulness and knowledge available are what makes this forum a cut above, long may it continue.

@C-T-C:

I take it a “low-rider” conversion is NOT about to happen?  “If it ain’t broke, don’t fix it” -where’s the fun in that?

I doubt that more extension is the reason as the fluid moves between above and below the piston as the shock extends and retracts. If more extension is required then a longer shock will be required.

Shock absorber canisters, whether affixed to the shock body or connected by a hose are promoted as providing extra oil capacity to keep the oil cooler under harsh operating conditions.

PS. The open and closed lenghts of the L494 shock would need to match the L405 shock if considering fitting the L494 shock. The fixed and bypass valves could be different too.

It’s actually for 3 reasons, I suppose:

Heat dissipation will be better, longer stroke needs greater displacement/oil volume, and greater volume results in lower operating pressure, resulting in the softer ride of the L405 vs the L494, so ride comfort in the L405 could be the primary reason?

This explains it well: https://www.elevatesuspension.com/blogs/ne...-shocks-v1

Interesting discussion. “If it ain’t broke, don’t fix it” -where’s the fun in that?

Thanks gang…
Don’t think I’ve ever given a shock absorber a second thought!
Both our 405’s have burst the same rear OS shock in a month! Bloody bad luck or??? 🤷‍♂️🤷‍♂️🤷‍♂️