Morris Minor Owners Club

Just checked front dampers. Undone bottom valve and about a cupful of black oil came out. Is it possible to put white spirit or something similar through to wash them out before filling with fresh oil and secondly can the six screws be removed to remove filler plug mounting cover, to make for quicker filling.

Knowing my luck if I take this cover off without asking advice, all the innards of damper will shoot out.

Ian.

I replaced the oil in mine from the top by use of a syringe and a thin rubber tube! Both to suck out the old oil and replace the new!!

Bounce the suspension a few times to expel the old oil.

Expelling the old oil isnt the problem. Its putting new stuff in.
Someone must have been curious and taken cover off. Come on spill the beans, or pistons and springs!!!!
Ian.

Hi Ian,
No problem taking the top off, nothing will fly out but watch no dirt goes in. Also try and save the gasket. If I can find the thread I will post the topic for uprating them and it has an exploded view of what's inside etc. There is nothing magic about lever dampers and most problems with them can be sorted out on the bench. Don't undo the big 'bolt' at the bottom without a diagram!!!
Nigel

Cheers Nigel,
That will be very helpful as I dont seem to find anything in official manual or Haynes. Is it possible to take them to bits to clean them out. All black oil etc.
Ian.

How do you take the tops off? Referring to the back ones, they seem to be very stuck, and I daren't use any heavy tools

Onne,
Dont know yet. Havent got that far yet I started at front. May get to rear next w/end.
Ian.

I got plenty of time.

Ian, have PM you. Tops are a s*d to get off, its the gasket goo they use, on the bench use a rubber/wooden mallet.

I got them off. There was an ounce of grit in them.

Ian - no need to take the tops off. Just carefully remove the bottom valve assembly - catch the little spring and any loose bits of the valve. gently rock the car - and as you say thin black oil (often stinking) runs out. The oil gets ruined by squirting through the valves - the long chains get ripped apart! I then just filled up with oil of my choice - and rocked the car again and again until only clean oil came out. Then replace the valve assembly and fill up - rock until air comes out - repeat over and over - and then check again a week later. I use 20w50 oil (and have used EP90 in the past) - but many on here disagree with this - it's your choice. Whatever you use - it's well worth tightening up the fixing bolts - especially for the front dampers.
I would be very interested in a copy of the 'uprating' advice if anyone has that ??

Was told that its best to jack car up under chassis, then fill up fronts. The same bloke also said engine oil would perish seals in dampers. Is that right or not?
Ian.

Didn't perish the seals in the Rally Minor (EP 90) - or cause any leaks, and the Traveller has had 20w50 in for 6 years now with no trubble at all! If you jack up the car then you won't be able to bounce it - just do it the easy way without any jacking - I concede a bit more difficult at the back where one damper has to be partly taken off to get the filling hole horizontal - but the basic principle applies!

Just thought I,d ask, as I didn,t want to replace dampers 12 month down line.
Ian.

Does the type of oil used affect the damping rate? If so is it a considerable effect?

Does the type of oil used affect the damping rate? If so is it a considerable effect?

Yes and Yes.
The correct oil is available, but generally accepted to be the same as 'hydraulic jack oil'.

The general rule is that hydraulic oils and mineral oils (engine oil, axle oil etc..) should never be substituted as they are completely different animals. They need different seal materials and either one will ruin seals intended for the other.

For the front dampers I've no idea how they seal or what materials are used so I'll not comment on that specific one.

Well i assume mineral oils are ok as i believe the workshop mineral advises a 20w oil (which i assumeis a mineral oil)

Well i assume mineral oils are ok as i believe the workshop mineral advises a 20w oil (which i assumeis a mineral oil)

20W is only a measure of the viscosity.
Hopefully someone here will know (rather than guess) which of the 2 families the shock oil comes from.

Hydraulic oil is exactly the same type of oil as engine oil - we use large drums of it (engine oil that is) at work for extremely high accuracy presses - it has more additives /wear resistance properties than simple 'straight' hydraulic oil - it will NOT damage seals intended for 'jack' oil.