Has anyone rebuilt shock absorbers

[Davezj]

I have a leaking shock, it is an old tein HA i am tempted to get some shock oil and see what happens when i strip it down. i can get an almost infinite range of O-rings from a local supplier so i am hoping it will be a simple stip and replace, they are not gas charged shocks so i just need to refill with oil and bleed the air out, i am hoping i can get to the seal i need to but if all else fails i can always send them back to tein for a refurb and pay the money.

so my real question is has anyone got any experiance of doing shock rufubs from a leaking seal point of view.

all info gratefully received.

[Davezj]

hasn't anybody tried to rebuild shocks

[wintertidenz]

Why would you risk rebuilding it yourself and have it fail while you're driving down the road, potentially causing an accident?

I would leave it to the professionals, personally. It's not something to muck around with.

[Davezj]

but that is like saying why would you rebuild your bakes if they fail it will cause a big accident.

They do not seem to be complicated items, and you see motorcycle forks and suspension being stripped and rebuilt all the time.
i have watch lots of videos about revalving your shock to change the damper rates etc. so it cant be that hard to replace a couple of seals.

it is just finding the parts to do it with, tein offer a refurb service but they charge £100-£200 per shock to do. they don't sell the internal parts separately so they have you over a barrel.
i will have to pull one of my shocks apart and find out what is going on inside, and what seals are like need replacing.
but it is not something i can do in the house, my wife would go potty. so i will have to wait for some better weather so i can do it out side.

it has not stopped rain in the UK for about 2 months now and i can't plan on doing anything out side in the shed as i have to take half the stuff out of the shed so i can get in.
i have got to much stuff.

story of my life though.

[Tam]

Hi Dave,
I gave rebuilt loads of motorcycle forks but never a rear shock but on bikes these are pressurised. However it's easy to get parts (seals and bushes) for forks from dealers.
Might be worth stripping it down and taking the parts to a suspension place ( I can think if loads for bikes but not cars) and see if they can get the parts. I'd expect a car shock to be easy as it does not have a spring inside and that's the hardest part with forks.
If you would like how to do forks I can photo a procedure out of one of my manuals.
What's the worse that can happen, this is what I thought when I did my turbos.
Hope this helps.
Marc

[Gingerfish]

At the re-furb prices, you might as well buy new! :dizzy2:

I know what you mean about there not being "kits" available. I took a bit of a flyer on my D2 brakes fitting as they were specifically for an Evo, but it worked out pretty well in the end.

The only way to know for sure if you can do it yourself is to just bite the bullet and strip it.
I'd go for it dude. The worst you can do is take it to peices, then if all else fails the re-furb service can put it back together.

Most of the seals and such must be available off the shelf.

[Davezj]

Cheers for the info Tam, i don't think my shocks are gas filled.
if they are then that will make it a tad more difficult as i will have to weld a plate on the outside of the shock body drill it weld a car tyre valve (schrader valve)on to it and then get a tyre place to fill the shock with nitrogen to about 50-60psi i think.
but a good test to see if you shocks are gas filled with gas is to strip the spring off and compress the shock and let go, if it returns to full extension on its own, then it is gas filled it is stays compressed then it is not, or it is just broken. In that case you will have to do the check on the other side shock to verify.

but if i am going to do a DIY shock rebuild at some point then i will have to do both rears to be sure.

[Davezj]

At the re-furb prices, you might as well buy new! :dizzy2:

I know what you mean about there not being "kits" available. I took a bit of a flyer on my D2 brakes fitting as they were specifically for an Evo, but it worked out pretty well in the end.

The only way to know for sure if you can do it yourself is to just bite the bullet and strip it.
I'd go for it dude. The worst you can do is take it to peices, then if all else fails the re-furb service can put it back together.

Most of the seals and such must be available off the shelf.

I will give it a go when the weather gets a bit better.

[adaxo]

What sort of oil you going to use? and what amount of it?

I have a close look at my rear tein as its also leak oil and they seems to be designed to be refurb at some point, not like standard shocks, tbh I would never even try to split 'non refurb-able' shocks, especially gas filled.

[Davezj]

you can get suspension oil from anywhere.
here is a video of a guy rebuilding hes teins
http://www.youtube.com/watch?v=Z-FEn4-hfLY

Here is a straight forward rubuild of a quantum black shock
http://www.youtube.com/watch?v=cAvCschxqxI

[exevoowner]

Can you find specs for the oil used in them as you need to know how much n spec then set yourself up to get it done

[Davezj]

Well a little update, i managed to stip the shocks down.

the one that was leaking had oil that looked like bailys in it a lite milky chocolate colour.
the other rear shock have grey oil with is what i expected.

i am trying to see if i can revitalise the top rubber seal, well it looks like rubber. so only time will tell, only because i can't find anyone that sells shock seals for tein's or some kind of universal seal.
Unfortunately the top seal on the actual piston is not a simple set of O-rings but one big seal. not sure what i can do with it apart from try and swell it up a bit so that it seals on the piston shaft.

i will post up some pictures later today. the shocks are really simple things as long as you don't stip the valave assembly, which you don't have to do unless you want to change the damping rate. My shocks have adjustable damping on them anyway so it is not something i would want to anyway.

The issue i had with this particular shock was a slight weep on the top seal and after stipping the spring off it i noticed that the compression damping was as expected and had resistance but the extention resistance was almost non existant. So when i stripped it down i only 180ml of oil in the shock, which was this milky brown colour, which suggests some water contamination (immulsification). I suppose if oil can get out of the seal water can get in.
In the inner tube of the shock there was oil under the valve on the piston bit no oil above it in the tube, which is why it did not have much extension resistance.

I think the tein twin tube shock which what this HA is should take about 250ml of oil so it had lost quite a bit.
There nothing wrong with the other rear shock but i will clean it out and change the oil in that one as well considering it is dark grey colour.

well that is all for now, i am just waiting for the oil to turn up. before i rebuild them.

[adaxo]

May you car try to send them a message and see what they suggest http://www.tein.co.uk/online_shop/contact/online_inquiry.html

[Tam]

Hi Dave,

If the top seal is similar to stuff on bikes they sometimes have a number on which might help. Sounds like the sort if seal for either forks or gear linkage seals. Lots of aftermarket motorbike suspension shops rebuild shocks so must be able to get them.
With fluid quantity could always drain the one that's not leaking and put same amount in.

Marc

[Davezj]

Hi Dave,

If the top seal is similar to stuff on bikes they sometimes have a number on which might help. Sounds like the sort if seal for either forks or gear linkage seals. Lots of aftermarket motorbike suspension shops rebuild shocks so must be able to get them.
With fluid quantity could always drain the one that's not leaking and put same amount in.

Marc

Yes with regard to quantity of oil to that is a good idea, i will use the other shock as a guide to the quantity.
you will see when i take the picture tonight, i have saved the milky brown oil and put it in a small wine bottle so i can compare it to the other shocks oil when i drain it. i just did not have another small wine bottle to pour it into.

I will take pictures of all the parts in the shock and the seal that leak slightly.
i am trying a old trick of soaking the seal in auto trans/PAS leak stop fluid. all this does is makes the seal expand slightly which stops some leaks. so hopefully over night the seal will expand slightly and fit the shaft a little better.

as i said above the tein HA's are twin tube shocks so they work like this,

http://www.youtube.com/watch?v=vcSH2z706rU
watch from about 25 second in and explans how a twin tube shock works, it is very interesting and it must be an easy topic as i now understand it.

Tein do make mono tube shocks as well but they are pressureised with nitrogen and need to be refilled after a refurb. the nitrogen shock are a much more efficient design as they stop any cavitaion of the oil in the shock when rappid damping is done. It stops bubles of air from forming in the oil which reduces the damping efficiency, the twin tube shock can suffer from tis cavitation issue.

[Davezj]

re are the pics of the inside parts of a Tein HA twin tube shock absorber (non gas filled)

66822668236682466825668266682766828668296683066833

1 Top seal nut
2 is mount bearing
3 adjustable piston rod
4 adjustabe damper valve
5 O-Ring seal which goes round top seal nut.
6 bottom valve
7 inner compression tube
8 outer shock body

this is how it goes together,
Part 6 goes on to the end of part 7 and part 2 , 3 ,4 go inside part 7. This assemply then goes into part 8 and part 5 gets put round part 1 and this goes over part 3 and screws into part 8.

but you do have to fill it with oil. there is nothing to it really.

you can see the top seal nut in the stop leak, which it will stay in over night and will see how it fits on the to adjustable piston rod in the morning to see if the seal has expanded or not.

Side note:-
not sure why the pics are there at the bottom of the post i can't seem to delete them

[Davezj]

well here is a slight update over night, the top seal nut in the stop leak over night seems a little bit tighter on the the piston shaft.

this seal is only an oil scraper effectively, as the shock is not pressureised so i am hoping maybe a another 24 hrs in the stop leak will make it slightly tighter again as this seal was rock solid, would not flex at all, had no movement, when i first removed the nut, but now has a bit of give. only time will tell.

[exevoowner]

Good little write up dave such a important part we all need

[giblet]

Great write up, useful info for the other Tein owners on the forum. Looking forward to seeing how they perform once you have rebuilt and fitted them.

[Davezj]

At present i am only talking about Tein HA shock as this is what i have, tey are quite and old set and old design, which means they are not gas charged and of twin tube design. i am not sure how well other types of gas charged tein shocks will lend themselfs to rebiulding/refurb, they may been more complex work on the to rechange the gas (nitrogen) side of there design.

For my HA shocks,
I am going to do just both rears for now as the front have no leaks at all and seem to perform well.
as i am changing the shock oil for a brand and thickness that is different from the original, because i can't any info on what tein actually use. i am expecting the dampering rate to change and possibley the shocks not to work at all due to the thinness oil the new oil.The oil viscosity is key to the valving in the shock that control the damping rate if it is to thin it will not work.

The oil i have chosen to first is suposidly very good stuff 'ed Line likewater' there are different grads of this oil, which i did not realise when i bought it. so i got the lightest grade they do by mistake. i will try it but i think i might have to go for the next grade up, slightly ticker viscosity. but as this is a learning curve me, i am prepared to do the testing so other do not have to.
On the outside of the bolltle of the oil it does say that this oil is very thin and may require changing the valveing in the shock to get the most out of the damper. i do not want to change the valveing so if it does not perform as expected, i will just buy the next grade up (thicker viscosity) clean the shock again and try it. if that does not work, then i will go for the next grade up again, and so on.

the oil is not mega expensive, but it is still about £15 for a bottle, which might be just enough to do oth rear shocks but not quite enough to do both from shocks as they need more oil as they have a bigger resovoir.

only time will tell.

if anyone has any more info on this subject, fell free to post it up and let us all know what you think.

[adaxo]

On this video (https://www.youtube.com/watch?v=tu85Fnx8UPU) they got quite thin oil too, as yours, scroll to 2:50, is very similar to what you show me so you may not far off.

[Davezj]

yes i have seen this video i think he is using pro circuit PC-02 oil.

I have also read that most factory motor bike shock come with a 5W oil fitted a standard form the factory. not sure how relivant this is to car suspension shocks.
there seems to almost no info on the the web about car shocks and what oil to use if you are rebuilding them. i suppose it is to do with the fact most shocks are sealed for life and you just throw the shock cartridge away when it has been removed from the strut (Macpherson strut type).

loads of people with motor bikes seal to change the shock settings and oil and revalve them on a race by race basis, but no info on car shocks.

[Davezj]

Well i have been busy to taday as we did not get to go to the Lake distric as Vicky is unwell.

so i decided to put my shocks back together.

but first i had to empty the second non leaking rear shock of its original oil to find out how much oil was supposed to be in the shock. I did this and found it was about 220ml of oil.

so i cleaned the non leaking shock and and filled it with 225ml of Red Line Likewater clear type oil the thinest and most stable (releative to heat) shock oil they do. I reassembled the shock and all seems to work fine with no leaks on hand compression and extension.
so i did the same for the shock that was leaking, the seal had been soaking in 'leak stop' for about a week, and when i fitted it it felt exactly the same tightness on the piston shaft as the none leaking seal.
which is nice.
i hand compressed and extended the shock piston and it operated in a similar way to the none leaking shock. the shaft of the piston remained clean and oil free when doing the compression and extension.

So i will have to rebuild the shock and spring in to one, and refit them to the car and see if the shock leaks under normal use, hopefully not.



I would like to take the oppertunity to state that is shock rebuild is done to a twin tube type shock which is none gas charged. the tein HA's are quite an old design of shock whick maybe why it is not gas charged.
most modern shocks are gas charged so they will need recharging if you are going to rebuild your own.