strange sounds from pump

[632 Regal]

auto leveling... in 4-5 second cycles I hear a pisst/whirr sound and the engine lowers rpms when it cycles.

The CH7 fluid is below the screen whe off but wondering if this is normal. Fluid is not real dirty, belts tight pump dont get hot either. Is this normal? If not what do I look for, havent pumped the **** outta the brakes and checked it yet as it is on ramps for me to finish the suspension replacement.

[632 Regal]

auto leveling... in 4-5 second cycles I hear a pisst/whirr sound and the engine lowers rpms when it cycles.

The CH7 fluid is below the screen when not running but wondering if this is normal. Fluid is not real dirty, belts tight, pump dont get hot either. Is this normal? If not what do I look for, havent pumped the **** outta the brakes and checked it yet as it is on ramps for me to finish the suspension replacement.

[grave77]

this is one of the annoying options in 8 series, I read something somewhere about 8 series that just don't buy the one with the auto-leveling cuz it's pain.

but I guess in ur case u already have it and u need to figure out whats going on, so as u always say ... go to basics, replace the hydraulic fluid and do a full flush, you can also check for leaks around the pump and the high pressure hoses. hydraulic systems hates air bubbles and that causes the pump to get noisy by time.

after all the mess u saw in the engine, don't expect to find a perfect maintained hydraulic system too. so you might think about replacing the hydraulic pump too.

[shogun]

I had that on my E32 750 power steering - which is also with Pentosin because it uses same reservoir and has a double pump for PS and LAD - when I turned the steering wheel to either roght or left side till the end.
Got a good advise from an old BMW Meister to change the filter in the reservoir and there is another filter in the ASC+T line (small item but costs 50$) and to check the pressure lines to the power steering pump, as he suspected that ine of these copper(?) washers where this hollow screw goes into the pump and hplds the pressure line was tightened too much and squeezed and could hinder full flow.
That is the small filter
http://8810.teacup.com/750hiline/img/bbs/0000258M.jpg

Did that and no more noise.

[632 Regal]

after doing conciderable reading I believe it to be the brake bomb. This is on order and I will flush and change the canister filter. I will also remove the small filter and try to clean it out mattering on the material it is made from.

My fluid looks real ugly and I am looking forward of ridding it of the stuff. A complete change of all fluids will be performed also as there is NO history available at all on this vehicle.

[winfred]

i've seen 7 series with lad make odd noise cycles when someone ****s with the level sensor and gets the system at the wrong ride height

[632 Regal]

twas the bomb, no cycling sounds or pump whirring...lots and lots of tiny bubbles that need to come out of the fluid tho. Amazing how the brake peddle feels now, like it has power brakes now. Quite a lot of things to get out of the way to work on it from the top side.

[grave77]

congratulations ... I was wondering what's that sound when I hit the brakes few times, something like a kick feel then a hissing sound, is this thingy the Bomb?

[632 Regal]

yes, the bomb is an accumulator to hold pressure for the brakes when the car is off.

[grave77]

so it's normal to hear and feel it when it works?

[632 Regal]

not really, the pump charges it in its leasure, if you hear it instantly you might have a bomb leak or 1 of 5 bazillion other problems.

so it's normal to hear and feel it when it works?

[Omega]

there is NO history available at all on this vehicle.

In the UK you can ring BMW-UK and give them the VIN number. They will then give you all the history of the vehicle along with the contact details of every BMW garage the car has been registered with, for free....... :D

Maybe BMW-NA do the same? Surely it's worth the cost of a phone call?

[grave77]

I just hear it kicks every once in a while, or if I hit the brakes while parking few times I hear the same kick every 6 - 8 brake hits like the AC clutch going on but I feel it in the brakes and the steering. I just been wondering if that's normal or I have something wrong.

[632 Regal]

thats not normal by any means, the pump is constant so you shouldnt feel much at all. the brake bombs are common source as I have been reading on them. How does you fluid look anyways? Mines stil a decent shade of **** and will be changing it out a few more times



I just hear it kicks every once in a while, or if I hit the brakes while parking few times I hear the same kick every 6 - 8 brake hits like the AC clutch going on but I feel it in the brakes and the steering. I just been wondering if that's normal or I have something wrong.

[grave77]

well the fluid looks alright maybe I need to check it from the brake pistons, although braking is alright, it's just that kicking I feel and hear, I just wanted to know if this feeling is normal or not, and now your saying that it shouldn't be felt. that means it's not fine but maybe it's a noisy but still working and it will be down soon ... am I right here?