1998 940 Celebration Steering Rack change

[360beast]

Originally Posted by Laird Scooby

You could contact someone like Pirtek Ian to create a "hybrid" pipe for you - steel from the rack to a certain point where it changes to rubber. If it is only a return pipe then there will be little or no pressure in it, just flow back to the reservoir (RTT = Return To Tank) so arguably a simple fitting into the rack with an elbow hose-barb for a suitable size rubber hose to return the PAS fluid would be adequate.






I read this last post before remembering the rest of the thread - taken completely out of context like that it was a case of "OOoooooooooooooo-errrrrrrrrr Missus! "

We used portal to make one of these braided hoses for us as they were out of stock and the car had to go. Absolutely brilliant and better quality than the original part!

You dirty bugger Dave!

[Laird Scooby]

Originally Posted by 360beast

You dirty bugger Dave!

Me?

[Ian21401]

I hadn’t realised that that comment could be misconstrued.
Re those pipes. There may be some misunderstanding here.
The ones I am referring to do not return to the fluid reservoir. Those ones are definitely flexible.
My rack has two rigid metal pipes located externally along it’s length. These are the ones which, if not a accurately bent and fitted with non standard short unions at each end, foul the sub frame.
One end of each one is fitted into the “pinion box” of the rack near to where the pipes from the compressor are fitted.
One pipe is longer than the other.
The other end of the long one is fitted into the rack housing near the far end of the rack.
The other end of the shorter one is fitted into the rack housing approximately at the middle point of the housing.
I may be completely wrong but my thinking is that those pipes return fluid, which has been displaced by the movement of the rack, back to the “pinion housing” so there must be some pressure within them, albeit not great.

[Laird Scooby]

Originally Posted by Ian21401

I hadn’t realised that that comment could be misconstrued.
Re those pipes. There may be some misunderstanding here.
The ones I am referring to do not return to the fluid reservoir. Those ones are definitely flexible.
My rack has two rigid metal pipes located externally along it’s length. These are the ones which, if not a accurately bent and fitted with non standard short unions at each end, foul the sub frame.
One end of each one is fitted into the “pinion box” of the rack near to where the pipes from the compressor are fitted.
One pipe is longer than the other.
The other end of the long one is fitted into the rack housing near the far end of the rack.
The other end of the shorter one is fitted into the rack housing approximately at the middle point of the housing.
I may be completely wrong but my thinking is that those pipes return fluid, which has been displaced by the movement of the rack, back to the “pinion housing” so there must be some pressure within them, albeit not great.

Probably my warped sense of humour and taking your comment out of context Ian!

I haven't investigated the internal architecture of the Volvo rack but from what you described, i would suggest there is a spool valve of some description in the pinion housing and this opens up to either end of a hydraulic ram inside the rack so at any given time, one end will be pressure and the other return. When you change the direction of the steering wheel, the pipes will change function and what was pressure will becom return and vice versa, all done by the valve in the pinon housing.

As such i would suggest both pipes should be either steel or some other high pressure material.

Are the pipes available from Volvo at all?

[Ian21401]

Thanks for your reply Dave.

I should have looked here before asking questions.

https://www.youtube.com/watch?v=amTnNkAhWgQ

https://www.youtube.com/watch?v=Jfgu0vgumK8

Re my problems with the pipework and unions on my steering rack, see my update in post 10 of this:
https://www.volvoforums.org.uk/showt...=steering+rack

As I mentioned in that post,the unions must have a total length, including the hex part, of exactly 15.5 mms. or 11.3 mms below the hex part. I did not mention that IIRC they are 7/16"x 20 (M11 X1.25 ).

At the time of the problem, March 2018, I enquired with my main dealer re replacement pipes. I was advised that there were at least three different styles of rack fitted through the life of the 940 and only one pipe was available, namely VO9140941 which I ordered but upon receipt was found to be completely different to what I required. As it was a "special order" it could not be returned/exchanged.
If anyone requires a hydraulic power steering pipe, part number VO9140941, they can have it for the cost of carriage as it is of no use to me and I would rather it helped someone.