I've actually got a number of questions about my 1990 300D:

1) Should power steering fluid turn "dark"?? I recently drained the old, replaced the filter and replaced fluid with Valvoline synthetic (nice, clear fluid). Now when I look at the fluid it has turned brown enough that I can no longer see the filter...

2) I have a slight leak on the low-pressure side of the power steering and wonder what type of hose I can use to replace this with??

3) I realized that my ALDA hose has been bypassed at the vacuum changeover switch because one of the nipples is broken on the switch. There appears to be 3 outlets on this switch, one on the bottom and two on the top in an L-shape with the top outlet covered by some type of cap--when I replace, how do I know which hose goes where and what damage can this cause until I can fix--I have read the posts about this and am unclear as some people say the engine could melt and others say bypassing is no problem?? Also, if you ask about performance, I have no comparison so don't know if the car is performing turbo-boost-wise as it should.

4) The steel "clips" that hold the vacuum hoses on these and other switches--are these the banjo fittings I keep reading about and regardless of that, how do you get them disconnected and reconnected??

<** adding after BillyBob's comments: that is helpful and based on what was said, the clamps I'm talking about are definitely NOT banjo fittings!! And they are not the clips that are what I call radiator "screw-tight" clamps but instead are clamps that look like they probably take a special tool to clamp on and I can't figure out how to get them off without ruining them--which may be the intent ;-) can the radiator clips be used for this application?? **>

Sorry for all the questions but had some time this weekend to check things out after reading a lot of stuff on this forum.

Thanks for all your help--I REALLY appreciate it from a novice-but-learning-lots-from-this-forum mechanic!! Mike

I'll take a stab at a couple of your questions

1) I recently did the exact same thing with the same results. I assume that not all the old fluid is ever drained + the lining of the rubber hose parts probably contribute to this coloration effect + it seems that synthetic fluids like this often have a dilutive effect on the glaze and varnish deposits that are characteristic of past dino fluid use.

2) Don't know for sure but a good quality hydraulic hose will work for sure and probably any similarly sized reinforced neoprene hose would be serviceable or you could visit the dealer!

3)I'm not sure of your exact setup but it appears that it is the overboost limit switch you have bypassed. This is probably not good as there is effectively no limitation to the increased stress that turbo charging could subject your engine to. The theory is that more air and fuel will be combusted than your engine's cooling system is capable of handling and some engine parts will overheat and eventually fail, pistons, valves, and cylinder heads are closest to the combustion occurring. Will you operate your engine at a high enough speed and for a long enough duration to have this happen probably not but at the cost of engines and their parts would yo like to find that point of no return!

4)Not sure about the "steel clips" your referring to, on my vacuum system small steel clamps secure plastic vacuum pipes and rubber connecters together, these are loosened and tightened by Philips head screws. Banjo fitting/connectors are a fitting that is bolted through with a hollow or perforated bolt allowing some fluid/gas to pass out/into a device through the inside if the bolt and through the section of the banjo fitting that surrounds the hollow bolt stem. Usually this fitting application effectively forms a 90 degree turn in the hose or line. A common easily viewable application for these banjo fittings is the connections into and out of the canister fuel filter housing. You unbolt the through bolt and remove it thereby freeing the actual banjo fitting itself. Seals or washers either aluminum or copper are often used on both sides of the fitting to seal the connection and some through bolts may have an o-ring or two fitted on their bolt stem. The banjo fitting itself is shaped somewhat like a banjo with the bolt going through the doughnut shaped body and usually a hose bib fitting for the neck hence the name "Banjo" Some of thse answers may help!


Yeah see zbenz's post, by your updated desciption these sound like compression clips. A pair of regular slip jointed pliers with serated jaws works great. These clips are designed to be always applying presure. The only place I've run into them on my car is where the low pressure PS hose connects to the steel pipe ends on the resevior fitting and the steering box fitting.

You can get the specific power steering return hose from the dealer or online parts shop. Pretty reasonable at about $0.10 per centimeter. You need about 40 cm to replace all 2 or 3 sections, if I remember.

The Vavoline fluid is a synthetic blend (not 100% synthetic) and it is an excellent fluid that contains some seal consitioner.

The clips you talk of are a spring steel compression clamp if you use a pair of pliers you can squeeze the "ears" on them together and they will loosen enough to move the hose. Hope this helps.

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87 300SDL 220K
85 300SD 218K
82 diesel Chevette 440K
85 subaru 4WD turbo
83 4.1L buick powered cutlass THE TOY

couple of add'l comments vs. editing my original post.

1) loubapache says for the power steering hose you can replace the 2 or 3 sections?? I only see one tube from the reservoir down to what I assume (as a novice!) is the steering box...am i missing something??

2) for the overboost switch--i will replace that here pretty quickly but still not sure which vacuum lines will go where--any help??!!

3) unfortunately my compression clamps are not of the ear type--the "ears" are closed and I don't know how to get them off without totally mangling them...here is my best attempt at a picture!! <** see that my picture is not showing up too good...anyway it is the circular part then like a neck and a closed loop...I plan on replacing these with the "ear" clamps **>
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1) loubapache says for the power steering hose you can replace the 2 or 3 sections?? I only see one tube from the reservoir down to what I assume (as a novice!) is the steering box...am i missing something??
>>
Do you see some small metal tubes going to the front of the radiator? There are more rubber hoses to couple these.

One hose goes on each lower connection -- should be fairly obvious by where they easily fit. The capped "connection" on the top is the vent -- when the valve is actuated, the pressure is vented out the top instead of being applied to the ALDA and increasing fuel delivered. I'll take a peak at mine tonight and see how they are connected there.

The overboost switch isn't there to prevent "eventual" overheating -- it is there to prevent overboosting and rapid destruction of the engine if the wastegate controller fails closed -- the turbo will produce about 20 psi of boost at full throttle if the wastegate stays closed, and the "effective" compression will then be high enough, with added fuel, to fail the rods, head gasket, and possibly head bolts. This engine cannot withstand that kind of boost for more than a few seconds!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!