Middle. The tape should be held with some tension on it, and the highest portion of the trim strip that touches the tape.
-Max -----Original Message----- From: mercedes-boun...@okiebenz.com [mailto:mercedes-boun...@okiebenz.com] On Behalf Of andrew strasfogel Sent: Monday, July 12, 2010 10:17 AM To: Mercedes Discussion List Subject: Re: [MBZ] W123 wagon with jarring ride and and inaccuratespeedometer What part of the chrome trim strip - top, bottom, or middle?? On Mon, Jul 12, 2010 at 8:18 AM, Dillon, Meade M CIV SPAWARSYSCEN-ATLANTIC, 53310 <meade.m.dil...@navy.mil> wrote: > Also, there is a shade-tree method for determining if your car's rear > end height is correct or not. You should find 19 inches measuring > from the center of the star in the wheel straight up and over the lip > of the fender to the chrome/rubber trim strip. Plus or minus 0.5 > inches is probably acceptable. > > -Max > > -----Original Message----- > From: mercedes-boun...@okiebenz.com > [mailto:mercedes-boun...@okiebenz.com] On Behalf Of David Bruckmann > Sent: Sunday, July 11, 2010 6:17 PM > To: mercedes@okiebenz.com > Subject: Re: [MBZ] W123 wagon with jarring ride and and inaccurate > speedometer > > I would proceed in the following order: > > 1. Check the rubber mounts at the top of the strut. If you had bad > spheres, these mounts may well be pulverised/absent. Check also the > bottom balljoint. > > 2. Test the function of the levelling valve (see instructions below) > > 3. Remove and test/replace the strut. A small leak is no definitive > indication that it needs replacement (see permissible leakage below). > > Some clarifications/suggestions: > > Service document "32-501 - Functional Description" explains the role > of each of the levelling system components. This document is available > at bruckmann.com/32-501.pdf and is also on the 115, 107, 123, and 126 > service manual discs. > > -the nitrogen spheres provide variable-rate springing (only) when > there is hydraulic pressure present. They do NOT have the damping > effect of a shock absorber. > > -the shock absorbers/dampers are simple flow-constricting perforated > discs located inside the struts. They travel back and forth on the end > of the piston, constricting flow in both directions. They don't > normally "wear out" because there are no moving parts. I suppose it is > conceivable that flat spheres could damage the dampers (eg sudden > pressure increases over bumps causing the o-ring around the damper to > blow out). > > -the strut seals can eventually wear out, and will do so quicker if > your cells/spheres are flat because of sudden pressure increases. Poor > maintenance (infrequent fluid/filter changes, dusty roads) can shorten > the life of the seals. A bit of leakage is permissible, up to 0.4L / > 10,000km. > > -flat spheres will also destroy the ball joint at the bottom of the > strut as well as the rubber mounts at the top. > > The latter is why I'm asking whether you "feel" the jarring, or > whether you are just hearing it. If you just hear it, it could be the > ball joint or rubber mounts. > > If you are so inclined, it is possible to check the struts for correct > damping function. This is described in another service document > "32-510 > - Checking spring struts". > > > Here's an easy way to check that the levelling valve's base pressure > is working correctly: > > 1. Raise the rear of the vehicle on ramps (better yet over a pit) and > shut off the engine. Make sure the ramps are high enough to allow you > sufficient space not to be crushed when you lower the car's hydraulic > pressure and it drops a couple of inches! > > 2. Disconnect the leveling valve's lever from the sway bar. Put the > lever in "emptying" position (towards the ground; away from the bleed > screw) and leave it there. The car should NOT DROP. Then measure the > height of a specific point on the car relative to the ground. Wait an > hour or two. > > 5. After the delay (with engine off), measure the vehicle height again. > It should be exactly the same. If it is NOT, you have a leaky base > pressure valve. > > The next step is important: > > 6. Engine off, position a drain pan and relieve the base pressure by > opening the bleed screw on the levelling valve. The car MUST DROP > significantly. Measure the height. If the car did NOT drop, your base > pressure valve isn't working. A non-functional base pressure valve > will result in a lower-than-normal ride height and poor damping, which > is most often resolved (incorrectly) by setting the levelling valve to > "fill" until the correct height is achieved. That hack leads to > knocking noises, unstable ride height, and incorrect damping behaviour. > > Note that the base pressure valve is internal to the levelling valve > and operates completely independent of the position of the fill/drain lever. > The bleed screw is normally the only way of relieving the base > pressure (aside from opening one of the hydraulic lines). There's an > MB rebuild kit (used to be about $100) for the levelling valve that may revive it. > > You may also find that the behaviour is temperature dependent (worse > when hot). This further implicates the base pressure valve, which will > leak more when warm, causing lower pressure and generally bad > behaviour in the system. > > D. > > > Andrew Strasfogel wrote: > > > [snip] > >The second issue is the hard, jarring thumps in the rear when I drive > >over potholes. The lack of dampening was not cured when I installed > >new air cells (accumulator sphere). The tech pointed out, however, > >that one of my rear hydropneumatic struts was leaking slightly. This > >seemed strange, considering that the car rides high and doesn't > >settle when sitting. He said that the function of the struts was to > >act as a shock absorber, yet I thought that was the job of the air > >cells. Would > > >my problem resolve if I replaced the leaky strut? All other SLS > >components (pump, rear valve) seem to be in order. > > > > -- > David Bruckmann, Palo Alto, CA > Current Reality: > 1970 Mercedes-Benz 220/8 (200,000 km) > 1972 Mercedes-Benz 280SEL 4.5 (160,000 km) "Blauer Engel" > 1973 Mercedes-Benz 450SLC (200,000 km) "Lottie" > 1976 Citroen 2CV6 (145,000 km) "Piaf" http://dolly.bruckmann.com/ > 1976 Mercedes-Benz 300D/8 (200,000 km) "Willow" > 1979 Mercedes-Benz 300D (425,000 km) "Brown Betty" > Shady Past: > 1970 Citroen DS21 Pallas (170,000 km) "Goettin" > 1971 Citroen DS21 Pallas (137,000 km), 1972 Citroen DS21 Pallas > (502,000 > km) > 1978 Mercedes-Benz 300D (1,200,000 km or thereabouts) "Sieglinde" > 1979 Mercedes-Benz 300TD non-turbo (260,000 km) "Diva" > 1981 Citroen 2CV6 Charleston (120,00 0km), 1988 Merkur XR4Ti (209,000 > km) > 1981 Peugeot 505 GRD (350,000km), 1984 MB 300TD (385,000 km) "Gertraud" > 1985 Toyota Camry "The Slamry" (330,000 km) 1986 Renault 9 1.7L > (155,000 > km) > 2002 VW Golf GLS TDI "The Hated Golf" (74,000 km) > > ---------------------------------------------------------------------- > > _______________________________________ > http://www.okiebenz.com > For new and used parts go to www.okiebenz.com To search list archives > http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > _______________________________________ > http://www.okiebenz.com > For new and used parts go to www.okiebenz.com To search list archives > http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
