mk1-forum.net

Hello,

I successfully replaced the front right displacer with an ebay item. All went smashingly although the ride height on the right is now less than the left even though they are at the same pressure. Possible causes?

First, I filled the system with a hand pump (no vacuum) I have since driven around, then bled the system and refilled 3 times to displace any air. I am sure there will still be some air in there so could this be the cause.

Second, could i have purchased a different type of displacer? I have read about different colour bands and cooper s etc. I could not see any discernible colours but i do have a part number.

Luckily, the displacer came in a matched pair so i can always swap the left one to match if this is the case. In fact the ride on the right side of the car is now better. The car used to ride quite high in the back now the right hand side feels stiffer and rides level, the left side still rides high in the back.

Any suggestions much appreciated. Thanks again for all your help. A great wealth of knowledge. How did anyone get by before the internet.

Daniel

dan

the knuckle joint will, to some extent, set the height - as it wears the car will sit lower.

displacers will have different heights if they are secondhand as it depends on how much use and weight has been on them.

if your wanting to run the car level with the same pressures you will have to shim the knuckle joints to equalise the heights

Hi Daniel,
It would be worth popping the pump on again and checking the pressure, it is quite common for the car to settle after a bit of running. In the manual, they tell you not to be too concerned over pressure differential, concentrate more on equalizing ride heights.

Regards
Al

i,ve always gone by ride height, the guauge on the pumps are not terribly accurate.

Hi,
It could be the displacer is different and if you change the the other side to
match, it may solve the problem.

".....the knuckle joint will, to some extent, set the height - as it wears the car will sit lower."

Is this really true?? I can believe that thicker/longer knuckle joints at both ends would raise that side ..but I thought the front to rear rake was controlled by the rear spring??? Without the spring the suspension will basically settle on the front bump stops. So, can one knuckle really affect this??

Cheers, Ian

ian

it will, just like on a dry car

on a hydro car the suspension will settle as the knuckles wear, so you will have to pump it up to get the front to lift up - the back will lift as well, but not by the same amount.

on hydro cars you can 'trim' the rake/height of the car by machining the cups the knuckles fit into, then add or remove shims until the car is sitting correct with the pressures you want.

when my car was hydro i could run it at various heights and pressures - worked well until i ripped one of the front - back pipes off it!!!

The knuckle never changed. Just the displacer. I think i will drop the pressure on the right a little to bring them in line. Just have to slow down a little more on the speed bumps. Looks better lower anyway. I have a set of dampers to fit on the front. Might get those on the weekend. Cheers for all the suggestions.