Yorumlar için; http://www.bmwteam.net/board/index.php?showtopic=4597

ABS HİDROLİK POMPA TAMİRİ - 1995-96 E36 ABS WİTHOUT TRACTİON CONTROL (EXCEPT 318TI)

Has your ABS fault light come on and won't go off? By reading this FAQ, it is a good assumption that you have already had your ABS fault codes read. If not, get them read. Often the dealer will do this for free. There is no consumer-level tool (at least none under $2000) that will read the codes and reset your ABS light. The only way the light will go away is if the problem is addressed. The ABS controller module (this is separate from the car's ECU) always does a self-diagnostic when the car is started. Even if you just "reset" it, the light will come back the very next time you start the car, unless you actually correct the problem.

The light should go away by itself once the problem is corrected.

How to tell if this DIY applies to you:

Take a look at the diagnostic sheet the dealer (or independent mechanic) printed for you. Anything relating to the following more than likely indicates a problem with the ABS pump (remember, we're only dealing with 1995-96 w/out traction control):

• Left front inlet valve
• Right front inlet valve
• Left front outlet valve
• Right front outlet valve
• Rear axle outlet valve
• Rear axle inlet valve

And the dealer has probably quoted you something like $1400-$2000+ to fix, right? (Note: independent mechanic may charge a fee for reading the codes.)

If you have verified that it is indeed the pump, you can save yourself $2k by DIY. Bottom line is you have nothing to lose. The reason for this is that BMW will NOT service/repair hydro units. If anything at all goes wrong with the pump, even if it's just one loose wire, BMW will recommend replacing the ENTIRE UNIT at a substantial cost. So basically, if you break it even more by attempting to fix it, you are no worse off since you would have had to replace the whole f'n thing anyway.

Read this first:

• If you decide to do this repair, you do so of your own free will, and at your own risk.
• I cannot verify if this procedure will work for cars with AST (or ASC+T).
• For models prior to 1995, the principles should be the same, although you will need to refer to Bentley for the appropriate wiring diagrams. This FAQ is specifically for 1995-96 w/out traction control, excluding 318ti.
• Do not attempt this unless you are competent in bleeding brakes.
• You will need a saudering iron and a digital voltmeter, and be competent enough to know how to use them.
• You will need a Dremel with a snake extension and cutting attachment.
  Of particular interest are pages 27-33, which give the resistance readings, which you will use in this repair.

PARTS NEEDED

• Brake fluid (at least 32 oz)
• Small hose clamps.

1. REMOVE THE ABS PUMP (HYDRO UNIT)

Disconnect the negative battery terminal. Suck out as much of the brake fluid as you can from the fluid resevoir (a turkey baster works nicely). The pump is located beneath the master cyclinder. You'll have to remove your MAF from the throttle body. It is NOT necessary to remove the brake resevoir or master cylinder. It is a good idea to label all the lines so you know where everthing goes when you reassemble.

You may run into problems removing the hose clamps from the connections to the fluid resevoir. This is actually the hardest part of the whole DIY. BMW uses those lovely single-use sacrificial clamps. You will have to cut them off with your Dremel. DO THIS VERY SLOWLY AND CAREFULLY, or you will be buying a new fluid resevoir. Also be sure you have some replacement screw-type hose clamps ready for when you reassemble (unless you are masochistic and want to intall new single-use sacrificial clamps).

2. REMOVE PUMP

The pump is held in place by a single bolted rubber stopper in the front of the unit. There are two more stoppers in the aft of the pump which fit into two retaining cups. Loosen the front nut and tilt the front upwards, and pull the whole thing out. Warning: Be prepared for fluid spillage.

3. REMOVE BOTTOM PLATE

Marvel at your solenoids.

4. TEST ELECTRICAL CONNECTIONS

Refer to wiring diagram below. The diagram on the right (from Bentley) is only for 1995-96 without AST, excluding 318ti. The Table on the left is compiled from the Teves Mk IV manual.

From the Teves Mk IV manual that you downloaded, you can determine the expected resistances across the various valves. All the testing will be done at the 12-pin connector on the pump. You should be able to verify the faulty valve from your diagnostic sheet.

5. REMOVE FILAMENT WIRE

Un-sauder the filament wire. THIS THIN FILAMENT is the culprit. With age it sometimes cracks or tears or corrodes. Don't bother trying to find the break in the circuit, it is virtually impossible to see. Just remove the whole thing.

6. GASKET SEAL

Before reattaching the harness to the hydro, put a bead of gasket sealant on the edge where the harness mates with the pump body.

7. REWIRE THE VALVES

Here is the path for my particular unit. This isn't an exact tracing of the filament. I had to go the long way for some wires (for example, T to A to D to E to B ).

REWIRING IN PROGRESS

Commentary: After doing this little exercise, I realize why BMW went with filament wire instead of full-on gauge wires: filament is easier to install. The entire circuit is pre-printed & mass produced on the conductor film; all the assembler has to do is sauder all the pins in order, much faster on an assembly line. No need to route individual wires. The drawback is that the filament eventually corrodes or disintegrates, causing a fault.

8. VERIFY YOUR WIRING

Once you are done wiring, re-test the resistances at the pins using the table in step 4 above. If you did everything right, the readings should now be within spec.

9. GASKET SEAL & REASSEMBLY

Apply a bead of gasket seal before reinstalling the bottom plate. Then reinstall the hydro to your brake system.

Installation is the reverse of removal (I've always wanted to say that). Use new hose clamps in place of the ones you Dremeled off the hoses at the fluid resevoir.

10. BLEED BRAKES & CYCLE HYDRO VALVES

Bleed your brakes. Reconnect your battery. The ABS fault light should now go away. The car is now driveable, but you should cycle the valves in the pump to be sure you get every last trace of air out of the pump itself.

You can manually cycle the valves by jumpering the connection at the pump relay. See below for the location of the relay (red arrow).

To cycle the valves, jumper the valve circuit. I have included the relay schematic with the pin numbers. This diagram is also stamped onto the body of the relay. You want to jumper slot 30 to 87 (red line). PLEASE VERIFY that you are indeed jumpering the correct slots!!!! I say this just in case your model has the relay oriented differently.

Make sure your battery is connected. Do not put the key in the ignition (slot 30 is always hot). When you jumper it, you will hear the valves activating.

After you cycle the valves a few times, bleed your brakes again.

Congratulations. You have just saved $2000 or more in repairs. All for the cost of some brake fluid and a couple of hose clamps.