Interesting steering pump...

[av8r4aa]

I had a whiney hydraulic pump. It whined cold or hot.
Not loud but more than I thought it should.
Sometimes the steering wheel would get choppy in a tight turn.

The brake pedal pumps required to depressurize the bomb was about 8. I just installed
a brand new bomb so that was not problem.

Anyway, after installing my in house rebuilt pump, no more whine or groan.

I just dumped in new ATF in the canister and went for a test drive.
The new pump has better ( now easier) steering. Just a little bit less
muscle required to turn the wheel.

The interesting thing I noticed was after the test drive and leak check,
I popped the top of the canister. After NOW 15 brake pedal pumps
the bomb is empty. I serviced the reservoir to the specs.

I am no expert here but all things considered, if the bomb only took 8
pumps before the new steering pump, I think the new hydraulic pump is
producing more PSI. That or perhaps less bypass.

Any thoughts?

[Taylor Marshall]

15 pumps is normal, 8 is not. There was something wrong with your old bomb and your rebuilt pump is at normal spec.

Did you re build the pump yourself ? I'd very much like to hear about how that is done and any pitfalls to look out for as mine is whynging like a grounded teenager when it's cold out

[carsnplanes]

15 pumps is normal, 8 is not. There was something wrong with your old bomb and your rebuilt pump is at normal spec.

Did you re build the pump yourself ? I'd very much like to hear about how that is done and any pitfalls to look out for as mine is whynging like a grounded teenager when it's cold out

Must be because you left your teenager out in the cold, Taylor....ha ha!

Speaking of pumps and bombs, I can hear the pump refilling the bomb abnormally often. There is noise to it where if you don't use the brake you wouldn't normally hear any whining or groaning. Wonder if the pressure sensor on the bomb manifold is prematurely sensing a loss of pressure too early and asks the pump for a refill often. Anybody hear theirs? I get about 12 applications so I think the bomb is ok.

[av8r4aa]

Speaking of pumps and bombs, I can hear the pump refilling the bomb abnormally often. There is noise to it where if you don't use the brake you wouldn't normally hear any whining or groaning. Wonder if the pressure sensor on the bomb manifold is prematurely sensing a loss of pressure too early and asks the pump for a refill often. Anybody hear theirs? I get about 12 applications so I think the bomb is ok.[/QUOTE]


I had the same problem with my system, it seemed to be refilling the bomb too often.
A few brake applications and it would refill. If you have a noisy pump I might try a rebuild. I did mine and it was easy. Somewhere here there is a pictorial.
Don't let the vanes fly out!

As for your other hydralic questions, I just replaced damn near everything
brake or hydraulic so I KNOW that it was the steering pump.
Give it a try.


15 pumps is normal, 8 is not. There was something wrong with your old bomb and your rebuilt pump is at normal spec.

Did you re build the pump yourself ? I'd very much like to hear about how that is done and any pitfalls to look out for as mine is whynging like a grounded teenager when it's cold out


Check around for the directions. big coupe, or somewhere don't remember.
Chris knows everything maybe he will chime in. The rebuild is super simple.
Most of the time is spent cleaning the external.
rebuild kit is 25 to 30 dollars.

Surprisingly, the new (rebuilt) pump is nearly silent.

[carsnplanes]

Speaking of pumps and bombs, I can hear the pump refilling the bomb abnormally often. There is noise to it where if you don't use the brake you wouldn't normally hear any whining or groaning. Wonder if the pressure sensor on the bomb manifold is prematurely sensing a loss of pressure too early and asks the pump for a refill often. Anybody hear theirs? I get about 12 applications so I think the bomb is ok.


I had the same problem with my system, it seemed to be refilling the bomb too often.
A few brake applications and it would refill. If you have a noisy pump I might try a rebuild. I did mine and it was easy. Somewhere here there is a pictorial.
Don't let the vanes fly out!

As for your other hydralic questions, I just replaced damn near everything
brake or hydraulic so I KNOW that it was the steering pump.
Give it a try.




Check around for the directions. big coupe, or somewhere don't remember.
Chris knows everything maybe he will chime in. The rebuild is super simple.
Most of the time is spent cleaning the external.
rebuild kit is 25 to 30 dollars.

Surprisingly, the new (rebuilt) pump is nearly silent.[/QUOTE]

But the pump is constantly providing pressure so if the pump was bad and needing a rebuild, it would be noisy all the time. Like I said, there is this "pump noise" that lasts only several seconds, seemingly when I apply the brake, say, twice (two consecutive brake applications) where it appears to be bringing the hydraulic pressure back to normal pressure.


Speaking of pumps and bombs, I can hear the pump refilling the bomb abnormally often. There is noise to it where if you don't use the brake you wouldn't normally hear any whining or groaning. Wonder if the pressure sensor on the bomb manifold is prematurely sensing a loss of pressure too early and asks the pump for a refill often. Anybody hear theirs? I get about 12 applications so I think the bomb is ok.


I had the same problem with my system, it seemed to be refilling the bomb too often.
A few brake applications and it would refill. If you have a noisy pump I might try a rebuild. I did mine and it was easy. Somewhere here there is a pictorial.
Don't let the vanes fly out!

As for your other hydralic questions, I just replaced damn near everything
brake or hydraulic so I KNOW that it was the steering pump.
Give it a try.




Check around for the directions. big coupe, or somewhere don't remember.
Chris knows everything maybe he will chime in. The rebuild is super simple.
Most of the time is spent cleaning the external.
rebuild kit is 25 to 30 dollars.

Surprisingly, the new (rebuilt) pump is nearly silent.[/QUOTE]

But the pump is constantly providing pressure so if the pump was bad and needing a rebuild, it would be noisy all the time. Like I said, there is this "pump noise" that lasts only several seconds, seemingly when I apply the brake, say, twice (two consecutive brake applications) where it appears to be bringing the hydraulic pressure back to normal pressure. __________________

[av8r4aa]

But the pump is constantly providing pressure so if the pump was bad and needing a rebuild, it would be noisy all the time. Like I said, there is this "pump noise" that lasts only several seconds, seemingly when I apply the brake, say, twice (two consecutive brake applications) where it appears to be bringing the hydraulic pressure back to normal pressure. __________________[/QUOTE]

That is what mine was doing also.
I think my pump was not producing enough pressure.

As I understand it the pump fills up ther bomb. When the pressure is not
enough it draws "power" or pressure from the bomb. So when you hear the bomb being refilled more than usual I assumed that the pump is not
working correctly.

I replaced my pump and the constant "refilling " sound of the bomb went way.
Mine sounded high pitched, buzzing sound that would stop a few seconds after a hydraulic power request ie. brakes or steering.

CW6er is the master here.
He knows the correct answer.

[carsnplanes]

But the pump is constantly providing pressure so if the pump was bad and needing a rebuild, it would be noisy all the time. Like I said, there is this "pump noise" that lasts only several seconds, seemingly when I apply the brake, say, twice (two consecutive brake applications) where it appears to be bringing the hydraulic pressure back to normal pressure. __________________

That is what mine was doing also.
I think my pump was not producing enough pressure.

As I understand it the pump fills up ther bomb. When the pressure is not
enough it draws "power" or pressure from the bomb. So when you hear the bomb being refilled more than usual I assumed that the pump is not
working correctly.

I replaced my pump and the constant "refilling " sound of the bomb went way.
Mine sounded high pitched, buzzing sound that would stop a few seconds after a hydraulic power request ie. brakes or steering.

CW6er is the master here.
He knows the correct answer.[/QUOTE]

Yes, a working, buzzing sound. Exactly.

[av8r4aa]

I had no leaks in my hydraulic system. I had replaced all the low pressure return lines. I tried the quick fix of tightening the case bolts on the pump, but no changes. If your return lines are soggy better replace them also.

As you know there is a filter at the bottom of the reservoir.
Mine was clean, so I just blew it out with air.

I think you are hearing the same buzzing sound that I had.
Does your steering wheel get rachity in a tight turn?

Can you over tax the hydraulic system by lots of braking and steering
inputs at the same time, and your noise increases or takes longer to recover?

I have a brand new bomb here if you think you might need one.
In fact, I now have enough parts here to build another hydraulic system
BMW car if I ever need it.

Good luck on your problem......

[carsnplanes]

I had no leaks in my hydraulic system. I had replaced all the low pressure return lines. I tried the quick fix of tightening the case bolts on the pump, but no changes. If your return lines are soggy better replace them also.

As you know there is a filter at the bottom of the reservoir.
Mine was clean, so I just blew it out with air.

I think you are hearing the same buzzing sound that I had.
Does your steering wheel get rachity in a tight turn?

Can you over tax the hydraulic system by lots of braking and steering
inputs at the same time, and your noise increases or takes longer to recover?

I have a brand new bomb here if you think you might need one.
In fact, I now have enough parts here to build another hydraulic system
BMW car if I ever need it.

Good luck on your problem......

I get about 12 assisted brake applications so I think the bomb is good. I'll check the filter too. Thanks.

[CW6er]

15 pumps is normal, 8 is not. There was something wrong with your old bomb and your rebuilt pump is at normal spec.

Did you re build the pump yourself ? I'd very much like to hear about how
that is done and any pitfalls to look out for as mine is whynging like a grounded teenager when it's cold out

Here is a PDF by DaHose for rebuilding the Steering Pump:

http://bigcoupe.com/phpBB2/viewtopic.php?t=8236

[Taylor Marshall]

Wow ! That's perfect.
Thanks Chris and a big thanks to Jose for taking the time to put the pdf together.
A final question.....from whom does one obtain the rebuild kit ?
T.

[carsnplanes]

...yeah, what Taylor said. Where do you get a rebuild kit?. I may rebuild the spare from my 85 and install it in the 88. Should be a quick swap then. I'll rebuild the 88 and keep for spare or sell it.

[av8r4aa]

Hi guys,
I typed in the part number at Autohaus Arizona and they had it!
it is not a part that normally comes up, but the number is good.

[CW6er]

... I may rebuild the spare from my 85 and install it in the 88. Should be a quick swap then. I'll rebuild the 88 and keep for spare or sell it.

Check in the parts catalog first to see if they are the same pump, I seem to remember that there was a different, higher pressure pump and it may have been in the '88/'89 models?

________________


Wow ! That's perfect.
Thanks Chris and a big thanks to Jose for taking the time to put the pdf together.
A final question.....from whom does one obtain the rebuild kit ?
T.

The rebuild procedure is also in the free downloadable manual, and I believe the torques are in the Spec. book:

Free Downloadable Factory Workshop Manual (U.S. Spec after '82 - e28 based, including the M6) and a separate Factory Specification Book (you need the Spec book because torques/specs are not included in the Workshop Manual, however, most torques are given in the Bentley manual). The Workshop Manual is not the greatest, but you can't beat the price, and it is invaluable for the things not covered in the Bentley. It basically just lists the steps for replacing parts, very little in the way of Troubleshooting or System Descriptions are included, so it is best to still get the Bentley, and use the Factory Manual for e24 specific things that aren't in the Bentley:
http://bigcoupe.com/phpBB2/viewtopic.php?p=53625

[Bert Poliakoff]

Point to remember is...when replacing the high pressure hose, make absolute certain the new hose has a crimped collar in the middle of the hose. There is a restrictor in the line and that crimped goody is what holds it in place.\ and lets you know you have the right hose