Power steering not working; brake light on

[thrty8street]

The power steering does not seem to be working. Does anyone know the culprit of my issue?

Symptoms:
- Extremely difficult to move the steering wheel when the car is running at a stand-still (same feeling as when the car is off).
- The "Brake" light in the dash cluster is permanently on.
- The brake pedal is rock hard before startup, as mentioned in this thread: viewtopic.php?f=3&t=158802
- I believe the system is not bleeding properly (see below).


Other info:
- brake accumulator is one year old. I ordered a new one and it should be arriving next week. If that's not the issue, ill keep it as a spare.
- I tried bleeding the power steering system and only a few little bubbles came out through the reservoir. The fluid does NOT get frothy and does NOT change in height when bleeding, as mentioned in this DIY video: https://www.youtube.com/watch?v=YDNTygi ... k&index=10
- Replaced the brake pressure switches on the pressure regulator (voltage regulator)
- Checked the power steering fluid reservoir filter and it looks new/good condition
- Replaced the brake master cylinder one year ago
- Brake servo unit was recently rebuilt by Jay Stratton
- Recently replaced the accumulator o-ring, as described in this thread: viewtopic.php?f=3&t=158735
- Replaced the power steering and alternator belts with new ones
- No leaks anywhere

[Blue Shadow]

The brake light indicates the brake fluid is low, or the pressure is not right in either of the two sensors on the power flow regulator.

If the bomb dies, that doesn't affect the power steering which gets power from the power flow regulator. The bomb supplies pressure storage for the brake system.

Seems your pump isn't putting out or the power flow regulator is sick. There could be other issues but I'd look into those. If the pump isn't putting out the bomb will not fill up and the brake pedal will be hard car on or off and the pressure switches will turn on the dash light.

[thrty8street]

Thanks Blue Shadow! Will a rebuild from Jay potentially fix my issue if it's the pump, or will I need to source another pump? It seems like Jay's rebuild is more for fixing leaks. https://www.jaysbmwparts.com/work/power-steering-pumps. Can you recommend anywhere to source another pump?

[Mike W.]

Nothing against Jay, but I think it's unlikely to be the pump, so I'd do more investigation before a new/rebuilt pump.

Hopefully all the brake/power steering lines are plumbed and hooked up correctly. Assuming they are, does the P/S pump growl? Especially when cold? If so that means a leak on the suction side, repeat suction, which will not result in a fluid leak. Check the suction hose from the reservoir to the pump, it's a relatively inexpensive, medium quality hose. Replace it if you have any suspicions. The filter in the reservoir has been known to be a problem. There's lots of long threads on it and current availability. Search. How tight is the belt? On my 535 it seemed like it had to be crazy tight not to lose P/S in wet conditions. Alt would be fine, but P/S would go away if I went thru a puddle and it wasn't super tight. Lastly, and most important, tighten the bolts that hold the P/S pump together. Sounds dumb, but try tightening them. Not super tight, but tight. I was going nuts with mine and the pump growling when cold. No leaks, but finally I tightened the bolts. They weren't exactly loose, but not quite tight either. Bam, problem solved.

[vinceg101]

Nothing against Jay, but I think it's unlikely to be the pump, so I'd do more investigation before a new/rebuilt pump.

Besides, rebuilding the PS Pump is one of the easiest tasks you can do yourself. The seal kits are readily available and once you get the unit apart, the hardest thing after that is cleaning it.
Midway down page 2 in this thread: viewtopic.php?f=7&t=139465&start=25

[Blue Shadow]

Notice how Mike tiptoes over the bolt tightening. He did that because the bolts can break and that isn't a step in the right direction.

[thrty8street]

Thanks everyone for your help with this! Here is an update:

1. I tried to tighten the two bolts on the PS pump but they were already tight. They are 19mm and 22mm for those who may need to know in the future.



2. I tried to tighten the power steering belt a bit more but it would not go any further because the teeth on the PS adjuster were stripped (not my doing).

3. I checked the brake and power steering lines to make sure they are hooked up correctly. But honestly, I do not see how they could be installed incorrectly as I see only one way they can all fit. The PS pump does not growl, and have not heard it growl before.

4. I ordered a new suction hose from the reservoir to the pump which I will be installing when I receive it.

5. I had previously checked the PS reservoir filter and it looked new/good. I had previously ordered a replacement filter from Ivo Christov (https://www.e28specialist.com/product/b ... 0x70x35mm/) for an arm and a leg but did not switch it out since it looked fine.



6. Upon further inspection I noticed the high pressure PS line has a gash in it. It looks worse in real life than it does in the picture. Is this the source of my issue? It's strange because there were no leaks. The cheapest I've found it is about 260 Genuine BMW or 170 for a Gates from RockAuto.



7. I found a low mileage PFR on ebay which I bought just in case.

Any thoughts? Thanks again!

[Mike W.]

Thanks everyone for your help with this! Here is an update:

1. I tried to tighten the two bolts on the PS pump but they were already tight. They are 19mm and 22mm for those who may need to know in the future.

No, I'm talking about the bolts that hold the pump together, not the banjo ones for the hoses. Should be 13MM heads. Sounding less like your problem now, but still good to do.

2. I tried to tighten the power steering belt a bit more but it would not go any further because the teeth on the PS adjuster were stripped (not my doing).

Those things are more art than a mechanical device. Stick a small crowbar or big ass screwdriver in there and put some tension on it. Don't try to break it, but more pressure than it seems like there should be on it. You may need 3 hands to do it right, but it can be done. Buy a new belt if you're maxed out on the slot in the adjuster bracket.

6. Upon further inspection I noticed the high pressure PS line has a gash in it. It looks worse in real life than it does in the picture. Is this the source of my issue? It's strange because there were no leaks. The cheapest I've found it is about 260 Genuine BMW or 170 for a Gates from RockAuto.

Good to address it, it could definitely bite you long term, but not your problem now or else you'd have ATF spitting out at you. Many real auto parts stores or hydraulic shops will custom make hoses for far less. Work the phone. O'Reillys is not a real auto parts store.

[Blue Shadow]

6. Upon further inspection I noticed the high pressure PS line has a gash in it. It looks worse in real life than it does in the picture. Is this the source of my issue? It's strange because there were no leaks. The cheapest I've found it is about 260 Genuine BMW or 170 for a Gates from RockAuto.

I have had the high pressure PS line cause a loss of power steering. But the hose came apart at the flow regulator (metal piece in the middle of the hose) and the system dumped all the fluid at that point. The drive back to base was without power steering and without power brakes. Fortunately, it was only a mile.

That hose isn't the problem, yet. If you have all three sets of connectors hooked up to the pressure and level switches and get a red light, then there is a component problem...if your brake fluid level switch is closed (easily checked; ohm it out).

The Bentley/ETM state the pressure range for the PFR's two pressure switches.

[thrty8street]

Update #2

Same issues remain. The "Brake" light is still on and the brake pedal is hard as a rock. There is no change in the fluid level when I try to pump the brake pedal or turn on the car.

What I did:

1. Tightened all the 13mm bolts on the PS pump.
2. Tightened the PS belt as instructed. It was a two person job. I pried the PS pump with a large flat head screwdriver while another person tightened the bracket.
3. Replaced the PFR with a used united I bought on ebay with approx. 105k miles and installed a NEW accumulator. Installed the new pressure switches I had previously bought.
4. When I removed the old accumulator (approx. 1 year old) from my original PFR, there was absolutely no fluid inside the accumulator.
5. Replaced the suction hose from the reservoir to the pump with a new hose.
6. Did NOT replace the high pressure PS pump because the Gates unit sold at Rockauto was a different design and therefore did not fit. See pics below.

So at this point is it the PS pump? Is my BMC bad? Why is my brake pedal so hard? I am scratching my head here. I feel like this shouldn't be this difficult.

[Mike W.]

When I removed the old accumulator (approx. 1 year old) from my original PFR, there was absolutely no fluid inside the accumulator.

I'm not sure where, but we're getting somewhere. The quoted above is significant. While it may not take a rocket surgeons intellect to make this statement, it sounds like you're not getting any flow. Start with the basics, take the belt off the PS pump, disconnect the high pressure hose from the regulator and with the hose in a drip bucket, turn it over by hand. You should be pumping something. Nothing that would run anything, but if you can sort of spin it by hand, you should get some fluid out. If it seems like nothing is happening, I'd pull the pump and take it apart, it's a bit messy, but not complicated. If it does seem to pump, next stop is the regulator. I've not had that apart, if you do try to take it apart (but it seems you've already tried a spare?) be careful, one or more things inside are probably spring loaded waiting to jump out at you and go flying to parts unknown when you disassemble. Like take it apart inside a plastic bag.

[gadget73]

I once took apart a power steering pump to re-seal it and it never pumped again. Absolutely no idea what I did wrong, pulled it back apart 2 more times and very carefully compared it all to the service manual but no joy. It worked perfectly but leaked before I touched it. Stuck a spare reman I had on there, problem gone.

best I can figure is something was on the edge of failure and I disturbed it without realizing it.

[ahab]

I would change this, it can l prevent proper flow and it seems that's the one thing you haven't eliminated as a potential problem. Despite throwing an arm and a leg at it, what are you saving it for if not this situation?

[thrty8street]

Update #3

I took off the power steering belt and removed the high pressure line from the PFR and turned the PS pulley by hand in both directions. Not a single drop came out of the hose. The pulley did spin freely, however, with minimal resistance - not sure if that's good or bad.

I guess this means its the PS pump, then? I've read that the 533i pumps are different than the 535i pumps.

I haven't changed the filter but its on my to-do list.

I purchased a BMW power steering repair kit and will be repairing the pump as mentioned earlier in the thread.

https://www.fcpeuro.com/products/bmw-po ... 2411135880


PS pump out.

[thrty8street]

Update #4

I took apart the PS pump to rebuild it and I was in for a surprise....I see metal pieces and specs all over the place.

So does anyone have a known good pump I can buy? Is this Meyle brand pump good enough or should I go OEM (for an arm and a leg)?

https://www.ecstuning.com/b-meyle-parts ... 33969~mey/



Here is the damage:







Any advice?

[Mike W.]

Owwww, that looks ugly. At least you found a likely cause. Where to buy? I'd go for a used one, I don't know if I can recall hearing about one failing. New, used, whatever.

But... with that kind of carnage in there I'd flush everything I possibly could and flush it well. You don't need to circulate grit thru a new pump. Actually I'd flush, flush again, run it, drain and fill, run again, drain and fill, etc. A couple of quarts of ATF are cheap compared to a new pump. Oh yeah, a new filter. Even though you have a M30 car, I might go for the M20 housing, which includes filter at least short term. They're cheap and for a disposable filter might be the way to go.

[thrty8street]

Owwww, that looks ugly. At least you found a likely cause. Where to buy? I'd go for a used one, I don't know if I can recall hearing about one failing. New, used, whatever.

But... with that kind of carnage in there I'd flush everything I possibly could and flush it well. You don't need to circulate grit thru a new pump. Actually I'd flush, flush again, run it, drain and fill, run again, drain and fill, etc. A couple of quarts of ATF are cheap compared to a new pump. Oh yeah, a new filter. Even though you have a M30 car, I might go for the M20 housing, which includes filter at least short term. They're cheap and for a disposable filter might be the way to go.

Thanks, Mike! To do the flush, should I install all the lines back up to the new pump and filter, and then drain and fill?

[Mike W.]

I would probably remove all the lines, wash them out with solvent like paint thinner, blow them out then reinstall. The power brake regulator concerns me too, just do what you can on that. The problem is that stuff was circulating thru everything from the steering box to the brake booster and inbetween until it stopped pumping enough to circulate.

[thrty8street]

Update #5

Problem solved! No more brake light. What I did:

1. Removed all of the PS and steering box lines and cleaned them out with paint thinner. Allowed them to dry and reinstalled.

2. Installed a NEW power steering pump. Installed a new PS adjustment bar (# 12311719992) and nut (# 12317677914). The belt was a breeze to tighten.

3. Flushed the PS system several times with ATF.

4. Bled the PS steering system several times until no more bubbles or foam were visible in the reservoir.

Now the car steers smooth and quiet, the best it's ever been, actually. Also, the clutch pedal feel improved.

Thank you all for your help throughout this process! I could not have done it without you.

[gadget73]

Thats well worn. I've had to replace hydraulic pumps on fork lifts that had similar wear. This specific type of pump with the floating vanes needs tight clearances on the face more than around the outside. If there is too much space between the rotor and the side of the housing the fluid won't force the vanes out, and at that point it won't pump at all. The clearances around the outside are pretty much self-adjusting.

The clearances in hydraulic systems are quite small, and any dirt in the fluid just eats it up. Overheated fluid doesn't help either, the fluid is also the lube and when it gets good and roasted it doesn't lube very well. Lots of power steering systems have no filter at all, and the ones that do are more of a screen than any sort of fine particulate filter. It also very rarely gets changed so any metal that ends up in the fluid from wear just keeps going round and round.

[thrty8street]

Update #6

After driving for a few weeks without an issue, a leak has developed in-between the crush washers of the low pressure PS line to the PS pump. I ordered a new bolt and washers. Hopefully that solves the leak. Anyone know the torque spec to the PS line bolt? Do the washers have to be copper?

[Mike W.]

BMW seems to like copper washers for sealing. I kind of like the aluminum ones better because they're softer and crush better. But they probably know what they're talking about more than I do...

I do reuse both copper and Al washers at times, but I'll try to smooth them out on some sandpaper first. They're still kind of compressed and harder, but at least I start with a virgin surface. And it's worked well for me.

[gadget73]

If you re-use copper washers they should be annealed first. Heat with a propane torch until red hot, drop in water. Then use a bit of Scotchbrite or whatever to remove the crust from heating. Once compressed they work harden and don't seal nearly as well anymore but getting them hot makes it soft again.