Front dropping overnight - possibilities?

**Graeme** · 7th July 2018, 01:23 PM

The front has been dropping to the bump-stops overnight for a long time, with or without the 20A suspension fuse removed to prevent valves from being opened trying to level. All except 1 of the o-rings in the front valve block have now been replaced, with only the tiny one inside the cross-link valve piston rod still original because I couldn't get the plastic section apart without appearing to get close to breaking the plastic. This o-ring may indeed be the culprit but I can't risk damaging the component as the RR is my only registered vehicle. I can't spot any evidence of cracking in either part of the valve body. I've been unsuccessful in trying to spot escaping air using soapy water but I haven't remembered to immerse the valve in a container of water either time the guard liner was removed to prove the point, so perhaps I need to do that next.

Access to check the tightness of the airline connectors on the front springs appears to require the strut tops to be unbolted which then necessitates a wheel alignment. As I consider it unlikely that both connectors are leaking equally, I'm not inclined to unbolt the strut tops to check.

Any suggestions before purchasing a new valve block?

Edit: I'll swap front and rear valve blocks for an overnight test.

**Roverlord off road spares** · 7th July 2018, 05:43 PM

maybe you have another problem like a hole somewhere in the actual airbag?

**Graeme** · 7th July 2018, 06:17 PM

Thanks for the suggestion.

A hole in 1 air-spring should cause that corner to drop mostly with a lesser drop the other side unless there is also a leak in the cross-link valve between the 2 sides to allow the other side to drop at the same rate. It is possible that the cross-link valve has been allowing air to transfer slowly as it would not normally be spotted and that a leak has developed in 1 air-spring, at its airline connector or in the top seal which I think would be the most likely spot for a leak in this vehicle which is not very old.

Swapping the valve blocks should either keep the front up on both sides or perhaps drop on 1 corner if the fuse is pulled for the test but if both still drop then perhaps the top seals on both sides are leaking. IIRC they're not very reliable but I expected to do a lot more than 90K before they started leaking.

**rar110** · 11th July 2018, 09:19 PM

Any update Graeme?

**Graeme** · 12th July 2018, 08:12 PM

Not really progressed, having only checked for air leaking from the top mounting rubber bushes and that the nuts are tight. I need to recheck my earlier assessment that both sides drop evenly with the 20A fuse removed.

With reports of others with the same problem having replaced their front valve blocks to no avail and that mine was spotless internally, I'm reluctant to expend the time and effort to swap valve blocks without exhausting all simple checks.

Edit - I've pulled the fuse but it again dropped evenly.

**Graeme** · 17th July 2018, 04:44 PM

The source of the leak was indeed the front valve block, leaking from around one of the centre pins in the electrical socket which I assume is for the cross link valve. Although I had previously sprayed soapy water along the seam between the 2 halves, I hadn't dunked the block in a tub of water with the electrical connector unplugged, which on several occasions I had meant to do.

**Graeme** · 4th August 2018, 12:18 PM

A new, non-leaking front valve block didn't stop the dropping but soapy water found this whilst fully-extended - porous all the way around the bottom.

**justinc** · 4th August 2018, 12:36 PM

Wow. Grit etc ingress? 😟

**scarry** · 4th August 2018, 01:46 PM

The genuine LR valve block that was fitted to mine as it was dropping almost onto bump stops in 4 days,fixed the problem for 3 months.

Replaced again with another genuine LR valve block,and all good for over 12 months.

**Graeme** · 4th August 2018, 01:49 PM

I don't think that it has been damaged by grit as the holes are very fine, they are all the way round including on the engine side, the driver's side is totally leak-free and Arnotts advertise their replacements for the dry-rotting MY10-12 bags, which is not very good news for the other side.

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