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Heavy steering at parking speeds

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dks
Posts: 26
Joined: Mon Sep 30, 2013 11:56 am
Location: Brisbane, Australia

Heavy steering at parking speeds

Post by dks » Thu Jun 25, 2020 7:31 am

Hi guys,

Got a problem with the hydraulics.
The basic issue is the steering is unbelievably heavy at parking speeds.

Here's what has been done
  • Power steering pump – replaced with new one.
  • Power steering box – rebuilt.
  • Brake booster – rebuilt.
  • Accumulator – replaced with okay second hand part.
  • Pressure regulator – replaced with second hand part from working vehicle.
  • Oil reservoir – filters cleaned as well as line to pump.
I've just had a test drive and found
  • Braking is quite good.
  • Steering at 60kmph good.
  • Steering at low speed – really heavy – I can turn the wheel but my wife couldn’t.
My mechanic says the power steering pump gets very hot and thinks there is a flow restriction to the power steering pump (even though he has tested the line from the reservoir).

Anyone got any clues where to go next - there ain't nothing left to replace.

regards
...dave

'87 635
'84 323

Fedaykin633csi
Posts: 32
Joined: Mon Nov 18, 2019 9:45 pm
Location: Portland, OR

Re: Heavy steering at parking speeds

Post by Fedaykin633csi » Fri Jun 26, 2020 10:59 pm

Maybe time for a new filter in the hydraulic fluid reservoir?
1983 633CSi 5-speed Burgunrot, a slow burn 645CSi project
1984 528e Saphirblau

dks
Posts: 26
Joined: Mon Sep 30, 2013 11:56 am
Location: Brisbane, Australia

Re: Heavy steering at parking speeds

Post by dks » Sun Jun 28, 2020 5:08 am

Thanks - I think that is a good idea - the filter needs to be looked at.
I don't think it has ever been replaced and I'm sure it needs to be more often than that :D
...dave

'87 635
'84 323

plip1953
Bigcoupe 100 Post club
Posts: 216
Joined: Mon Aug 13, 2018 4:15 pm
Location: Leeds
Contact:

Re: Heavy steering at parking speeds

Post by plip1953 » Sun Jun 28, 2020 8:58 am

Is this video at all helpful?

https://www.youtube.com/watch?time_cont ... e=emb_logo

It seems to me that if pressure is available at the steering box input side, but there's no assistance being generated, then the problem must lie with the steering box itself. However, you suggest that powered steering is available at higher speeds so that would suggest the steering box is working, but pressure to it is lacking in certain situations.

Is there a known speed at which assistance begins? Is it gradual or like an on/off switch?

Last time I drove my car (2 years ago lol) I experienced a very strange set of circumstances whereby the steering assistance would suddenly fail, but this was at speed and was never apparent when stationary or at low speed. The brakes worked fine the entire time. My suspicion is some kind of issue with the valve assembly to which the pressure accumulator (bomb) is attached, and I have a secondhand unit to slot in when I eventually get round to it.

This thread may be worth a read...

viewtopic.php?f=17&t=29926
Phil
__________________________

1988 Highline 635 CSi

dks
Posts: 26
Joined: Mon Sep 30, 2013 11:56 am
Location: Brisbane, Australia

Re: Heavy steering at parking speeds

Post by dks » Sun Jun 28, 2020 12:54 pm

Thanks Phil.

The video was a good intro to the operation of these boxes.

Had a read of the thread you suggested - I've read it before but not the same.

There is steering assistance at driving speeds - I guess 10-15 kmph or more. So, I'm not convinced there is a steering box problem yet - but I haven't dismissed the idea either.

As you said, I think I need to do is to determine where the assistance kicks in.
I was thinking if there is no assistance when the car is almost stopped, put it in Neutral, give it a few revs and see if the assistance comes back.

I'll report back in the next couple of days.

regards, Dave.
...dave

'87 635
'84 323

emac
Posts: 54
Joined: Thu Feb 06, 2020 2:57 am
Location: SC

Re: Heavy steering at parking speeds

Post by emac » Wed Jul 01, 2020 2:28 am

does revving the engine change the PS assist? What does it feel like going lock to lock sitting still? Does it make noise?

Mine made some funny noises and I changed the filter and it helped. Fixing the broken steering box mount was also a big improvement.

dks
Posts: 26
Joined: Mon Sep 30, 2013 11:56 am
Location: Brisbane, Australia

Re: Heavy steering at parking speeds

Post by dks » Wed Jul 01, 2020 4:10 am

Hi emac

Just spoke to the hydraulics guys and they say just a few revs makes it all okay.

Seems like the PS pump isn’t giving enough pressure sometimes.

So I’m thinking the “new” PS pump isn’t so good.

No noises - we’ll just a bit at extreme lock.
Also mounting fixed ages ago.

Will certainly replace the filter soon too.
...dave

'87 635
'84 323

emac
Posts: 54
Joined: Thu Feb 06, 2020 2:57 am
Location: SC

Re: Heavy steering at parking speeds

Post by emac » Tue Jul 07, 2020 11:29 pm

Are you using the same size pulley on the new pump as the original?

dks
Posts: 26
Joined: Mon Sep 30, 2013 11:56 am
Location: Brisbane, Australia

Re: Heavy steering at parking speeds

Post by dks » Thu Jul 09, 2020 8:12 am

Hi emac,

As far as know - yes.
I drove the car yesterday and it was all okay.
I am told that the new PAS pump was generating enough pressure at idle and caused a valve in the regulator to not close off properly. Also, just a few more revs (up to about 1000) and everything is okay.
Again, I am told that the new pump was pulled apart and there was a little wear because of lack of flow and that is was rebuilt and now all okay.

I hope to get the full story in the nex few days and will report back.

The poor thing has been off the road since beginning of March - seal kits with missing seals, COVID-19 delays to deliveroes from UK to OZ, then the local couriers hacked and delivies taking another 2-3 weeks etc, etc - but it was nice to have a drive again.
...dave

'87 635
'84 323

plip1953
Bigcoupe 100 Post club
Posts: 216
Joined: Mon Aug 13, 2018 4:15 pm
Location: Leeds
Contact:

Re: Heavy steering at parking speeds

Post by plip1953 » Thu Jul 09, 2020 8:17 am

dks wrote:
Thu Jul 09, 2020 8:12 am

....... the new PAS pump was generating enough pressure at idle ......
"was or "wasn't"?
Phil
__________________________

1988 Highline 635 CSi

dks
Posts: 26
Joined: Mon Sep 30, 2013 11:56 am
Location: Brisbane, Australia

Re: Heavy steering at parking speeds

Post by dks » Thu Jul 09, 2020 9:54 am

Sorry - wasn’t
...dave

'87 635
'84 323

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