Announcement

Collapse
No announcement yet.

Slightly different control valves

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Slightly different control valves

    Just noticed a slight difference in my 2 control valves, on the left an early one from a 71 on the right a later one from a 73. The later one has 3 holes and larger drillings at the top for the return oil. Does anyone know if this would affect the operation of the Power steering?

    Terry Hunt, Wilmington Delaware

    www.terryhunt.co.uk

    #2
    My memory is that the earlier ones have more feel, less power assistance. Also the earlier ones had a different number of turns lock-to-lock.
    My memory could be faulty though.
    Richard
    Mabel is a white 1972 Mk1½, TV8, Mo/d.

    Comment


      #3
      Yes thats the strange thing, despite the 71 car being pretty early 71 both are the same turns lock to lock, (i.e 3) but they had different torsion rods, the earlier one being thinner which would make the earlier ones have more power assist, and I think thats correct. Looking at the parts manual I think the rack change happened later than my car, maybe late 73

      I'm leaning towards the later one but it has a mark in the area of the top seal that is concerning me, though when I took it apart it did not seem to have a bad leak there.

      The other strange thing is the drillings for the roll pins are 90 degrees out, which means you cannot mix them!
      Last edited by trunt; 2 November 2017, 14:46.
      Terry Hunt, Wilmington Delaware

      www.terryhunt.co.uk

      Comment


        #4
        if you refer to the workshop manual (57.00.06 ) there are 2 types of valve Alford and Adler and Adwest, the manual explains the difference and says they are described as being interchangeable.

        Hope this helps

        angel

        Steering Valve.jpg

        Comment


          #5
          Ok I did see that.

          These are both the same type, it's just details here. The adwest types are quite different.
          Terry Hunt, Wilmington Delaware

          www.terryhunt.co.uk

          Comment


            #6
            Cars are likely to have had a number of re-con racks already in their life, and I don't think suppliers differentiate between different years or specifications. So, the ones off each car may not be age-appropriate.
            '72 Manual O/d Saffron Yellow

            Comment


              #7
              Originally posted by davidf View Post
              Cars are likely to have had a number of re-con racks already in their life, and I don't think suppliers differentiate between different years or specifications. So, the ones off each car may not be age-appropriate.

              Yup, that's probably what I am seeing, here in the USA I'll bet that type of rack is common, (EDIT or maybe not? thats a British company I now know.)

              I think I saw the stag pump on a Pontiac amongst many others.
              Last edited by trunt; 2 November 2017, 22:56.
              Terry Hunt, Wilmington Delaware

              www.terryhunt.co.uk

              Comment


                #8
                MY spool valve was locking/ feeling very notchy , when the car was being driven in a straight line , very scary when you came to a corner, could not find any info about refurbishing the spool valve it's self from here or google, the rack people would not just refurbish the valve, so ended up buying a refurnished rack, but that is starting to leak as you don't get a lot for £130 (may 2015) 5,500 miles. so any info on the valve would be very useful. The actual resealing of the rack is an easy job, I kept my rack waiting for the repair of the valve.
                My rackP1060378.jpgP1060557.jpg Refurbished rackP1060556.jpgP1060560.jpgThe paint came off when handled.
                "The UK,s 2nd Most Easterly Stag" Quad Exhaust- ZF 4 Speed BOX

                Comment


                  #9
                  Originally posted by MandM View Post
                  could not find any info about refurbishing the spool valve it's self from here or google, the rack people would not just refurbish the valve, .
                  The problem with refurbishing the control valve is probably lack of spares, I doubt you will find anything except the PTFE seals found in the kit. It seems to me that aside from inspecting and then replacing seals there's not much you can do.

                  Having 2 of them helps!

                  My next job is installing those pesky seals and I plan on posting that -- if it goes well!

                  Just need to drink the bottle of wine first (that's the key part - you wait!)

                  Terry
                  Terry Hunt, Wilmington Delaware

                  www.terryhunt.co.uk

                  Comment


                    #10
                    OK so tonight I did the final assembly of my Control Valve, first job was to get a bottle of wine....

                    A cheeky little Riesling that had the bottle shape I desired. The reason was to stretch those PTFE seals enough to get them on. Using the wine bottle will make the stretch a little more even, something I wanted. I dropped the seals into a cup of just boiled water and left them there for a while, oiled up the wine bottle (not myself) then fished the seals out and pushed them down the bottle neck with as many fingers as I could, pushing the seal down maybe 1/2 inch was enough to stretch them enough to get them on. I found a little extra stretch was needed for the bottom ones as they started shrinking a little as they cooled and got harder to get over the last couple of places. In the end I had them all on but they were still too big, as you can see on the right.



                    Next, they need to be "resized" there is a bit of info on the internet on doing this with this type of seal mostly regarding Automatic transmissions, which use similar type seals. So I cut out some plastic from a gallon windscreen washer refill bottle, soft enough not to damage the seals, thin and clear enough to check what the seals are up to. I wrapped them in that and clamped them down with a couple of hose clamps. The first time I was a bit conservative on the clamping and they did not get much smaller, second time I clamped them firmly and backed off 1/2 a turn. Left them in a warm place and after a couple of hours they looked fine. If I squeezed them all to one side they showed about 1 mm - about what I saw on the old ones.



                    I then quickly assembled the bobbin to the shaft and inserted it all into the housing - it slipped in nicely. This can be done without fully disassembling like I did but if you do take the bobbin off, watch out when putting it back on as the bobbin can be assembled 180 degrees out, the 3 (2?) return oil drillings in the shaft need to be on the side where the two offset (left right) holes are, not the single central (high pressure in) hole which is at the rear.



                    I'm afraid its going to be a while before I test this rack but I think its going to be OK.
                    Last edited by trunt; 4 November 2017, 14:36.
                    Terry Hunt, Wilmington Delaware

                    www.terryhunt.co.uk

                    Comment


                      #11
                      Excellent work with the wine bottle! Thanks for a comprehensive report, this should be useful to many of us.

                      Richard
                      Richard
                      Mabel is a white 1972 Mk1½, TV8, Mo/d.

                      Comment


                        #12
                        Thanks Terry for the insight and tips, did you find anything in the spool valve that would cause the steering to feel momentarily hydraulically locked when you try to turn off centre and when it did turn with a harder pull there was a thud though the system but was ok when off centre (half turned), do you think a leak over the white seals would cause this?. The rack and pinon itself was in good condition (no damaged teeth,scores etc)

                        Thanks for your help

                        Martin

                        P.s when my steering was like this the passenger could feel/notice this locking syndrome
                        "The UK,s 2nd Most Easterly Stag" Quad Exhaust- ZF 4 Speed BOX

                        Comment


                          #13
                          I guess the seals could cause that,

                          I could imagine this:-

                          The magic happens in the bobbin. The center "groove" is at high pressure and as you turn the wheel the internal slots send pressure to either the lower or upper grooves to apply pressure to the left or right (the other being opened to return oil) If the seals were leaking then a bit of pressure would get to both grooves and it would be "locked" but once you open the slots enough to overcome the leak pressure perhaps it would start working...

                          I guess the same could happen if the internals were worn as well.

                          You can open it up quite easily and take a look, just remove the circlip and plastic spacer on the input shaft, support the flange and drift the input shaft down to release the bearing from the housing. The whole lot will come out. Release the wire clip and the bobbin will slide up and off, you can check it internally. Check the inside of the housing for wear as well
                          Last edited by trunt; 4 November 2017, 15:03.
                          Terry Hunt, Wilmington Delaware

                          www.terryhunt.co.uk

                          Comment


                            #14
                            Just to say that there will always be a bit of free play at the wheel if the pump isn't operating, as the spool valve rotates. It is sometimes necessary to remind an MOT tester to have the engine running when checking this, to avoid an unwarranted fail. Mind you, that will go away when we no longer have to get them tested!
                            Mike.

                            Comment


                              #15
                              I have just put my original rack back on the car, I change the Spool valve seals ( the White ones) after speaking to Terry on here (above).

                              20220717_150447.jpg 20220717_151924.jpg 20220717_152059.jpg







                              This rack did not leak but when you came down a duel carriageway to a roundabout after a high speed run , it felt like it had locked and you had pull very hard on the wheel to get it to go around the corner, once move off this straight head position it would be fine. I always felt that the oil was at high pressure on each side of the value keeping it central, it would move with a clonk even the passenger could hear it .

                              so have check the tracking and been out there is no clonk when driving, not been on a high speed run yet, but this rack has a total different feel to feels like it has less power assistance , the recon leaking one , feels light, no clonk but leaks badly now.

                              so does the seal effectiveness between the spool valve and the housing affect the feel of the steering rack , over light or not ??





                              have attached this tread below as well as I thought it would be useful to some.

                              Steering rack overhaul - Stag Owners Club Forum
                              "The UK,s 2nd Most Easterly Stag" Quad Exhaust- ZF 4 Speed BOX

                              Comment

                              canli bahis siteleri bahis siteleri ecebet.net
                              Chad fucks Amara Romanis ass on his top ?????????????? ???? ?????? ?????? ? ??????? fotos de hombres mostrando el pene
                              güvenilir bahis siteleri
                              Working...
                              X