Suspension Damper Overhaul

[Dominic]

Hi folks

I want to change the fluid in the dampers, as I do not know when this was last done, and have read past topics regarding which fluid to use. (I have chosen hydraulic jack oil.) I would prefer not to disassemble the front suspension, but would rather keep these dampers in place. Is the nut at the bottom on the inner side of the damper a drain plug? If so, does it require sealing washers on reassembly, or does it rely on a taper thread? I realise that the rears need to come off to top up the fluid, so obviously the filler can be used to drain in this case.
Thanking you for your time

Dom

[Cam]

I can't remember what seals the plug now but if you take the plug out there is a little valve in there that causes the restriction of oil flow and therefore the damper operation. The units will drain on removing that plug though.

[Alec]

Hello Dom,

it's not usually necessary to remove the rear dampers to top them up?

It is a while since I did ours, as it now has telescopics fitted, but I used to use an oil can filled with hydraulic oil to top both front and rear. (Much less spillage that way.) and found it easy to do the rears.

Alec

[Peetee]

I've done this a few times. You must bounce the suspension a few times to ensure all the oil has drained away. Likewise when topping up to ensure that any trapped air is released.

[bmcecosse]

Take the bottom plugs out - but be very careful not to lose any of the parts from the valve assembly. The valves can be adjusted and little shim washers put behind the springs if you want to. Otherwise just bounce up and down until all the old (probably stinking!) oil comes out - then flush through with some of your new oil - then put the plug back in (never had any leakage problems) and fill up the damper - lots more bouncing and filling to get the air out. In fact - it may take a few weeks to get all the air out - just keep topping up each weekend. One of the rears can be done ok on the car - the other is at a funny angle and you can't fill it right to the top unless you take it off. It's up to you what oil you use, but heavier oil does give better damping. While in there - knock back the lock tabs and tighten up the mounting bolts on the front dampers!

[Dominic]

Thanks for all that info chaps, very much appreciated!