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Old 07-14-2012, 12:53 PM
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collins912 collins912 is offline
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Location: Virginia (Hampton Roads)
Join Date: Jun 2009
Posts: 1,147
Mein Auto: 745i; 750Li; Yukon Denali
Replacing the Alternator/Oil cooler block off seal DIY

First, I would recommend is to make sure the vehicle is cool as with any job working on or around the engine. Safety first!

1. Drain all coolant into an absolute clean bucket or whatever container you have if you wish to reuse the coolant.

2. Drain your power steering(hydraulic) fluid in the same manner with a clean bucket. That's $40 a qt if you contaminate the fluid or simply just put new fluid in.(Thats up to you)

After these first two steps you can proceed to start doing the maintenance on your beautiful 7.

3. Carefully remove the Active Stabilizer Bar. Be sure not to break to smaller lines going into the oscillating motor. Label or mark the steel braided lines to make sure they go back into their original position.

There are 2 brackets with 2 nuts on each one that secures it to the front axle. Remove those I believe they are 10mm. Last portion to remove the bar are the swing supports which are connected right above both front tire.

NOTE: If the stud spins with the nut, you must insert a torx bit or torx screwdriver whatever you prefer. I'd recommend a bit on a ratchet. I believe that size is a Torx 30.
Now you can fully remove the Active Stabilizer Bar.

4. Next is going to be your bottom pulley or guide. Held in by 2 bolts. Remove that (having someone taking the tension off of the belt). Pull the drive belt up and out of the way so that it doesn't somehow come into contact with any hydraulic fluid (power steering fluid). If it does come in contact the belt must be changed. According to BMW that is. I wouldn't test that. Being that it's a critical part.

5. Power steering pump. There are three mounting points. Two bolt on the front and 1 one the back side. Now pay very close attention to the back mount(#6 in the pic below) make sure when you re-assemble this that you know how many threads are showing. Its basically an adjustment knob. Failure to do this will cause an annoying squeal on the drive belt. This is the main part to worry about re-installing in my opinion I didn't know what was causing that awful squeal.

6. Next will be your engine mount brace. There are 4 torx bolts(size 12 female torx socket) mounted to the side of the engine(this is where a lot of extensions and universals will come into play). Last bolt is mounted pointed downward through the engine mount. You can reach this one by looking to the ground from the top by the suspension/steering fluid reservoir.

7. Last but not least is your alternator bracket. Very simple to remove this one. Once removed take out the flattened old $4 seal and install your new one.(#2 in the second pic) Now just re-assemble in reverse order and service and top off all fluids drained.

I hope this helps with anyone who has this problem or just doesn't want to pay for the maintenance.
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Last edited by collins912; 07-14-2012 at 12:58 PM.
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