The following article gives detailed instructions on replacing the power steering pump on a BMW E36 3 series car. Even though we have used a 1996 BMW M3 to perform this repair, this article can be applied to any BMW E36 3 series vehicle with minor modifications.
A BMW E36 power steering pump replacement may be needed if your car’s steering wheel suddenly becomes difficult to turn.
The BMW E36 is a joy to drive…especially on twisting roads that test the vehicle’s suspension and steering system. It was one of the last “unmolested” cars manufactured by BMW…void of all of the fancy onboard electronics that in many ways ruined the 3 series’ pure driving experience.
Unfortunately our wonderful E36’s are reaching a geriatric age where many critical parts begin to fail. Time takes a toll on the engine’s mechanics, especially on the pumps and pulleys under the hood that have been subjected to repeated torture over the years. One of the parts of special concern is the BMW E36 power steering pump.
The power steering in your BMW E36 is a hydraulic, power assisted rack and pinion system that allows you to turn the steering wheel without exerting much effort. Simply put, the power steering pump pressurizes the power steering fluid that you add to the reservoir. The pressurized fluid applies force to a piston in the power steering rack when the steering wheel is turned, allowing the driver to turn the car with less effort…especially at low speeds.
Common signs of a failing power steering pump on your BMW E36 are a distinct “whining” sound coming from the pump or the vehicle’s steering wheel becoming more sluggish and difficult to turn. When the BMW E36 power steering pump completely fails, the vehicle will be nearly impossible to turn at low speeds without an enormous amount of force exerted on the steering wheel.
A failed BMW E36 power steering pump is a dangerous situation that can cause catastrophic damage to your car’s engine. A seized pump pulley can cause the main accessory (serpentine) belt to disintegrate, destroying the cars cooling system and potentially causing a blown engine. The power steering pump in your vehicle should be immediately replaced at the first sign of failure.
Determining what parts you need
In most circumstances, all you will need to do this repair is a new pump. Unless you experienced catastrophic failure of the pump that caused its shaft to seize up, the original pulley and accessory belt can be reused. It is often suggested that a power steering pump replacement creates an opportunity to replace the original BMW plastic pump pulley with a stronger aluminum one (or a new plastic one if an aluminum one is not available for your model car). While we do agree with this idea, it is not mandatory. If your plastic pump pulley is in excellent shape with no visible chips or cracks, it is perfectly acceptable to reuse it. We have provided links below for the correct replacement pulley for your model car.
Now is also a good time to replace your fluid reservoir. Fluid reservoirs have filters in them that tend to get clogged with gunk. They are relatively inexpensive and swapping them out with a new one only takes a few minutes. We have provided a link below so you purchase the correct one.
We also suggest replacing your accessory belt if it is showing signs of age or is nearing the end of its service life. Since you will need to pull off the accessory belt to replace the power steering pump, it is a great time to replace it. Once again, we provide links below to the correct belts for your model car.
You may need the production date of your BMW E36 3 series to purchase the correct pump. Get the production date for your vehicle from the drivers side door jamb label or by clicking on the link in the above caution box.
1. Power steering pump (required) – Always use a high quality replacement pump when doing this repair. Cheap generic “aftermarket” brand pumps are poorly made and have a high failure rate…what looks like a good deal today can end up costing you more money in the long run. The following pumps are excellent choices and fit most budgets.
2. Power steering fluid (required) – The BMW Repair Guide only recommends using Pentosin CHF 11S hydraulic fluid in the power steering system of your BMW E36 vehicle. Pentosin CHF 11S is specially formulated for high performance applications like used in the BMW 3 series car. Only 1 liter is required for this repair.
3. Power steering pump pulley (optional) – Although we list this part as optional, we highly recommend purchasing a new pulley when replacing your power steering pump. A new pulley is cheap insurance against future failure of your steering system.
4. Power steering fluid reservoir (optional) – Replacing the fluid reservoir is always a good idea when replacing the fluid in your power steering system. The reservoir has a filter built into the bottom of it, so replacing it ensures that your new fluid doesn’t become contaminated with old system debris.
5. Accessory belt (optional) – If you are doing this repair because your power steering pump failed, you may want to consider replacing your accessory belt. The accessory belt drives the power steering pump pulley and is a critical part of keeping your engine from overheating.
- Jack and support the front of your vehicle using the four corner wheel stand method as shown in our article BMW Jacking and Supporting for Repairs and Maintenance.
- Remove the air box assembly using a 3/8″ ratchet and 10mm socket. Disconnect the cruise control and lay to the side so it is not in the way.
- Remove the alternator air duct boot with flat blade screwdriver (see above image).
- Remove plastic cover from engine belt tensioner pulley. Using an 8mm hex socket, turn the bolt inside the tensioner pulley clockwise. Slip the main accessory belt off of the tensioner pulley. *Note: Unfortunately, unless you have part of your coolant system removed, you can’t get a good photo of this step. We have “borrowed” a photo from Bimmerforums.com member ApexSpeed. He used the following photo in an answer to a S52 serpentine belt/idler question.
- Next, slip belt off of the power steering pump pulley (you only need to remove the belt off of these two pulleys in this repair ).
- Empty power steering fluid reservoir by sucking out fluid using a vacuum pump.
- Place a 5 gallon drain pan under the power steering pump.
- There are two banjo bolts attaching the fluid hoses to the pump. They both have different size bolts holding them in. Remove the top M14 banjo bolt with a 19 mm socket and the bottom M16 banjo bolt with a 22mm socket, from the bottom of the car (you cannot get access to them from the top of the engine). Allow fluid to drain out of lines into pan.
- Remove the power steering reservoir return line using a flat blade screwdriver and let drain into pan. The return line is the hose that runs from the reservoir to the steering rack under the engine (see photo).
- Optional step if replacing power steering reservoir – Using a 10mm socket, loosen the reservoir mounting bracket and remove the reservoir from the car. Install new reservoir. Make sure mounting bracket bolt is snug…do not over tighten or you could crack reservoir.
- Now you must purge the rest of the fluid from the power steering system. In order to do this, the front wheels will need to be free so the steering wheel can be turned. If the car is on ramps, jack the front of the car up so the tires can turn freely. Reposition the 5 gallon drain pan so it is under the loose lines leading to the steering rack. The goal is to try and catch as much fluid as possible…don’t expect to catch it all and don’t be surprised when some of it sprays on the floor. Next, turn on the ignition (DO NOT start the car) and turn the steering wheel to the right until it stops (do not force it past the stopping point). Now turn the steering wheel to the left until it stops. Repeat this 2 more times. Your power steering system has now been purged of all of it’s fluid.
- Remove the three power steering mounting bolts using a 13mm socket. The bottom bolt will need to be removed from the bottom of the car. The other two bolts can be accessed from the top of the engine. One of the bolts is in a tight location (top bolt furthest in towards center of car), so have extra patience when removing. Remove the pump from the car and place on a workbench.
When doing a BMW E36 power steering pump replacement, it is recommended that you upgrade from the stock plastic pulley to a newer metal one. This is only a recommendation and not a requirement; if your original plastic pulley is in good shape (free of chips, cracks or scrapes), then reusing it is perfectly acceptable.
Removing and installing the pulley on an E36 power steering pump raises its own set of challenges; since the pulley spins on a shaft, trying to remove the bolts without somehow locking the pulley from spinning can become a lesson in futility. Further compounding the issue is that trying to remove and install the pulley while the pump is still on the vehicle is next to impossible. Don’t trust the photos you see online! You will never be able to torque the pulley bolts properly with the pump installed in the car.
The good news is the pulley bolts are at a relatively low torque (22Nm – 16ft lb) so removing and/or installing them is fairly easy. The trick is to immobilize the pulley without breaking it. This is easily done with an old accessory belt (or an inexpensive new one if you don’t have one lying around) and a table vice. Never attempt to remove or install pulley bolts with an impact wrench. This can cause damage to the pulley…it also may cause excess stress on the pump shaft leading to pump failure.
- Cut any “six ribbed” accessory belt you can find in half with a pair of shears. If you are replacing the accessory belt during this repair, use your old one. If you do not have an old belt, run to your local auto parts store and buy a cheap one…they have plenty of them for under 20 bucks.
- Wrap the accessory belt around the pulley twice and cut off excess.
- Place the pulley and pump into a table vice. Slowly tighten vice until pulley is secure. DO NOT overtighten. DO NOT allow vice jaws to touch pulley. They should only be pressing in on belt (see image below).
- Remove the three pulley bolts with a 13mm socket wrench.
- Carefully pull the old pump free of pulley. Leave the pulley in the vice.
- Install the new pump on the pulley and hand tighten the bolts. Torque bolts to 22Nm (16 ft-lb).
Reinstalling the pump is simply the reverse process of above, except you should replace the 4 banjo bolt “crush” washers (2 on each bolt) with new ones when installing the lines.
The following are the torque values for the bolts per the Bentley Manual:
Power steering pump to engine (including bracket) – 22 nm (16 ft-lb)
M14 (19mm) Banjo Bolt – 35 nm (26 ft-lb)
M16 (22mm) Banjo Bolt – 40 nm (30 ft-lb)
**Important installation notes:
- Be sure to re-install the 22mm (lower pump) banjo bolt first. If you re-install the 19mm (side) banjo bolt first, you will not be able to get a socket on the 22mm bolt.
- Since the power steering system is under pressure, it is very important to make sure the banjo bolts are torqued to spec. The 19mm banjo bolt is a little tricky since the front bumper is going to get in the way while trying to torque the bolt. Hold the metal hose fitting that attaches to the pump with one hand while using the torque wrench with the other. It will keep the fitting from turning with the bolt.
- Using a flexible spout funnel, fill the power steering reservoir with a high grade fluid like Redline D6 ATF.
- Bleed the system as follows: Start the engine. Turn the steering wheel all the way to the right until it locks (do not force past lock position), then all the way to the left until it locks. Repeat this procedure twice, then turn off the engine. Open reservoir and fill fluid to fill line. Replace cap.
- Start engine again and repeat step 2. Check fluid in reservoir and top off if necessary.