Topping up dampers.

Post by **dunketh** » Wed May 02, 2007 2:57 pm

Am I right in assuming you simply undo the bolt on top, removing whatever washers and whatnot are there then re-assemble them the same way in reverse?
Safe to empty them with a turkey baster and refil with my decided oil? (no I'm not getting into that one here!)

I've seen some diagrams that are frankly scarey - showing loads of washers just waiting to be lost.

Post by **chickenjohn** » Wed May 02, 2007 3:37 pm

You dont need to remove the whole top of the damper- just the bolt at the top. Empty the oil via this bolt hole, working the damper arm when you re-fill to remove bubbles.

Post by **bmcecosse** » Wed May 02, 2007 9:24 pm

To empty them properly - the old oil will be runny and often stinking! - you need to take out the little valve assembly at the base - and yes - don't lose the little washers and spring!! Then gently rock the car to expel the old oil, then flush through with the new oil of your choice, then re-fit the valve assy - and then top up with new oil, bouncing the car until all the air comes out. Despite your best efforts - more air will come out over the next week or two - so check and refill. If you want wobbly suspension - use jack oil, good suspension use 20W 50, Rally suspension use straight 40 oil - or even EP90!!

Post by **bigginger** » Wed May 02, 2007 11:07 pm

All the usual warnings, natch. I wonder why it was designed "wobbly"?

Post by **alex_holden** » Wed May 02, 2007 11:11 pm

For a softer ride on poor quality roads perhaps?

Post by **dunketh** » Thu May 03, 2007 12:00 pm

I'll need them nice and stiff. I'm fed up of my door handles scraping the tarmac when demonstrating the minors abilities to random t*ts in random newer cars.

Post by **Peetee** » Thu May 03, 2007 4:00 pm

I was happily using 20W oil which gave a more chuckable response to the suspension but it blew the seals on three of my dampers.

Post by **Packedup** » Fri May 04, 2007 1:22 am

I'm sure the Midget has 20 shock oil as standard - And the dampers are near identical in design from what i can tell.

I'm thinking of mixing 20 and 30 fork oil to give a 25% or so increase when I rebuild the suspension, though I suspect simply replacing the old chewed up oil with fresh woul probably make a notable difference on a lot of cars

Post by **Peetee** » Fri May 04, 2007 8:29 am

I'm sure the Midget has 20 shock oil as standard - And the dampers are near identical in design from what i can tell

Probably OK on new dampers then. Perhaps mine were past their best and 20 weight just hastened the inevitable.

Post by **Rob_Jennings** » Fri May 04, 2007 8:54 am

dunketh wrote:I'll need them nice and stiff. I'm fed up of my door handles scraping the tarmac when demonstrating the minors abilities to random t*ts in random newer cars.

changing the damper oil will not stop much of the lean, dampers only effect short term roll and hop, you need stiffer torsion bars or an anti roll bar to reduce lean on corners.

Post by **bmcecosse** » Fri May 04, 2007 9:15 am

This is true for long corners - but for little wiggles the dampers do a grand job - especially if beefed up with tele dampers in addition to the levers. Driving a car with little or NO lean is a very un-nerving experience.

Post by **Dominic** » Fri May 04, 2007 6:50 pm

Driving a car with little or NO lean is a very un-nerving experience.

I was lucky enough when I was about 9 to have a ride in a recently restored Bugatti racer (not sure which marque). My Dad's friend collected them when a box of rusty bits was still cheap! My abiding memory was of going round corners at the same speed as on the straight, with no noticeable lean! Weird, but exciting!

Post by **Dru** » Tue May 15, 2007 2:39 pm

I've just taken the rear dampers off and drained and refilled them... the first time in a VERY long time, by the look of it... one of the dampers is now very slack on the compression stroke, only stiffening up towards the end of it. I'd pumped it and pumped it while filling, and seemed to have got in as much oil (hydraulic jack oil, ISO 32) as possible.

Any suggestions as to what may be wrong?

Post by **Stig** » Tue May 15, 2007 5:19 pm

If you need a replacement I've got an old pair sitting in a box in my garage if you're ever heading up the M4.

Post by **Dru** » Tue May 15, 2007 9:20 pm

That's a kind offer, and thank you; but I've got a workshop manual* on the way after a bit of E-baying, and will delve deeper into the damper before giving up on it.

*as in, hopefully, a proper one rather than the Haynes job I got. THHHRRRP.

Post by **alex_holden** » Tue May 15, 2007 9:47 pm

I suspect there may still be air trapped inside - it took ages to get all the bubbles out of mine.

Post by **bmcecosse** » Wed May 16, 2007 4:55 pm

Assuming none of the valve assembly (little spring + spacer washers) was lost during the draining - then it will just be air. Mount the damper vertically in a vice top it right up - and slowly move the arm from one end to the other of the stroke. May take a while!

Post by **Dru** » Wed May 16, 2007 6:46 pm

I did spend some time pumping it... then I gave up and remounted it... then I drove twenty miles or so with it (had to pick someone up from the airport)... then took it off again and tried again.

The level was still up to the top.

I'm pretty certain that all the springs and washers went back in as they should...

I presume there's some piston arrangement inside. I don't want to go the whole hog with dismantling the unit just yet, as there's a BMC manual on its way which will hopefully be some use. Maybe the bore is worn?

Post by **bmcecosse** » Wed May 16, 2007 8:34 pm

Was it like that when you first took it off the car ? ie Flopping about uselessly ?

Post by **Dru** » Thu May 17, 2007 6:32 am

Not flopping - it isn't flopping now, just moving rather freely - but it was pretty ropey, and there was only a bit of sludge in there... I've mentioned it to the garage, as they're going to sort out one of the front wheel bearings which is a bit worn; and they'll sort out the damper at the same time.

I was just trying to fix the things that I can sort out easily enough myself without much expense, as a big part of the reason for getting the car in the first place was that I could service it myself. I've done a few other little niggly jobs that needed doing, although the six months mechanical guarantee has still got a fair way to run.