mr henderson
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| posted on 30/5/09 at 10:59 AM |
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Using a power steering rack without the power?
Power steering will still work without the power of course, as that is an essential safety feature. However, the unassisted steering is fairly heavy
and presumably this is caused not only by the fact that the racks are usually quite 'quick' but also because of the mechanism itself
causing some drag.
Does anyone happen to know if a power steering rack can be modified so that it is usable without the power? especially from a legal point of view?
Thanks in anticipation
John
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tegwin
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| posted on 30/5/09 at 11:02 AM |
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The ratios are usually differnt in asssisted racks...
And if there is any evidence that it was once a PAS rack... it will fail an MOT because "if its fitted it has to work" and ergo... a pas
rack with no hydraulic feed is not cosher!
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www.verticalhorizonsmedia.tv
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mr henderson
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| posted on 30/5/09 at 11:11 AM |
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quote:
Originally posted by tegwin
And if there is any evidence that it was once a PAS rack... it will fail an MOT because "if its fitted it has to work" and ergo... a pas
rack with no hydraulic feed is not cosher!
Indeed, but what I was hoping to find out was whether it was possible to modify a PAS rack so that that problem wouldn't arise.
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mad4x4
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| posted on 30/5/09 at 12:51 PM |
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Saxo's and peugeot 106's have electric PAS pumps - Could use that to power it
Scot's do it better in Kilts.
MK INDY's Don't Self Centre Regardless of MK Setting !
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HAL 1
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| posted on 30/5/09 at 12:54 PM |
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If you were to do this then i suppose you'd have to use some form of lubrication other than the fluid used in PAS, which i believe is quite
highly pressurised, it's still under pressure when the engine is stopped hence the heavy steering, if you were to release the pressure then the
rack should be easier to turn, I THINK !
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HAL 1
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| posted on 30/5/09 at 12:56 PM |
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quote:
Originally posted by mad4x4
Saxo's and peugeot 106's have electric PAS pumps - Could use that to power it
i was thinking along those lines for my car but it's not too heavy so i'll stick with manual
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mr henderson
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| posted on 30/5/09 at 01:07 PM |
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quote:
Originally posted by mad4x4
Saxo's and peugeot 106's have electric PAS pumps - Could use that to power it
That's interesting, do you mean that the pumps are conventional (as in engine driven pumps)?
As you may have deduced, my problem is that I can't conveniently use an engine driven pump, I've got nothing against PAS as such (in fact,
I like it)
John
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Volvorsport
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| posted on 30/5/09 at 01:12 PM |
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quite a few cars are now using electric PAS pumps , vauxhall being one of them .
the problem as i see it , is that you have seals in there to prevent fluid loss(hence making the rack work) , which if oil gets in or you havent got
rid of all the oil - itll lock up when you dont really want to .
take all the gubbins out , and decide for yourself if teh rack will operate smoothly etc .
May we enquire as to why you need to convert one ?
www.dbsmotorsport.co.uk
getting dirty under a bus
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turbodisplay
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| posted on 30/5/09 at 01:24 PM |
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Some racks have external hydraulic rams which can be removed.
Next thing to be removed is the valve unit.
Darren
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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mr henderson
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| posted on 30/5/09 at 01:28 PM |
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quote:
Originally posted by Volvorsport
May we enquire as to why you need to convert one ?
Yes, you may. I am working on a project that utilises various Ford bits, including the PAS rack. It incorporates a Duratec engine, and once the air
conditoning pump is removed, it makes retaining the power steering pump particuarly problematic in terms of the belt drive. Another solution, although
not easy, I should imagine, would be to modify the AC pump so that its pulley could be used as an idler.
John
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Peteff
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| posted on 30/5/09 at 01:41 PM |
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quote:
Originally posted by Volvorsport
quite a few cars are now using electric PAS pumps , vauxhall being one of them .
Vauxhall Corsa use a power assisted steering column not a pump to power the rack and they read the engine speed from the electronic dash to cut
assistance when not needed.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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snapper
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| posted on 30/5/09 at 01:47 PM |
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Won't fail MOT if the power steering pump is not fitted.
The Sierra ratio is about 2.7 , the power steering rack is 2.4.
To use a power steering rack as a quick rack take off the flexi pipes, connect the fixed tubes on the rack together with one bit of flexi pipe,
before connecting both pipes together add some power steering fluid, keeps things lubricated.
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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rusty nuts
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| posted on 30/5/09 at 01:49 PM |
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But the later Astra's has the PAS electric pump mounted to the bulkhead complete with resorvoir .
The AC compressor has an electric clutch so that the compressor doesn't turn when not needed . Pity it's so bulky
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bram boekestein
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| posted on 30/5/09 at 02:10 PM |
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Miata people use it a lot, as a sort of quickrack. They remove the R&P out of it and remove the seals, put it back together and blank off the PAS
fluid ports.
Here is a guide:
Miata PAS removal
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MikeRJ
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| posted on 30/5/09 at 02:21 PM |
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The valve assembly in PAS racks contains a torsion bar which operates the valve, under manual operation this will be subject to a lot of force, and
will therefore add unwanted lost motion to the steering.
This has been covered dozens of times in the past.
[Edited on 30/5/09 by MikeRJ]
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mr henderson
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| posted on 30/5/09 at 02:50 PM |
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quote:
Originally posted by MikeRJ
This has been covered dozens of times in the past.
Tiny bit of exaggeration there, do you think?
Anyway, even if it has been covered 'dozens' of times, the answers tend to be different and knowledge does advance. A search on the
subject will produce many different opinions, none of which are conclusive.
Are you sure that the Miata solution linked to above won't work in my case?
John
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Wheels244
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| posted on 30/5/09 at 03:58 PM |
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Most MNR's were supplied with PAS racks ( if ordered from them ) up until recently when they've gone over to Escorts.
Mine has one fitted, has been modified by MNR to fit.
It doesn't have any pipes on it or anything else connected - the ratio of a PAS rack gives a quick rack.
It works fine - nice and light and passed SVA recently with it.
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Ferg
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| posted on 30/5/09 at 04:07 PM |
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I retro fitted power steering to our Saxo. Bought pump, rack, pipes and loom all off e-bay for £60.
We used a Saxo pump on our 6R4 with a Cavalier power rack.
The only thing to be careful of with the Saxo pump is that it uses a feed tied in with the alternator so that it doesn't run until the
alternator is charging. Otherwise I suppose you might struggle to turn the engine over adequately while that pump is spinning.
Electric columns are good, but need a strong dash rail....
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mr henderson
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| posted on 30/5/09 at 04:16 PM |
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Thanks for all the replies, it would seem that the ideal solution would be for me to use the rack as is and obtain an electic pump. Power steering
would be useful in this application so that's what I will go with.
John
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MikeRJ
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| posted on 30/5/09 at 06:32 PM |
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quote:
Originally posted by mr henderson
quote:
Originally posted by MikeRJ
This has been covered dozens of times in the past.
Tiny bit of exaggeration there, do you think?
No I don't. Look back through the archives if you can be bothered, it really has been asked many times before.
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mr henderson
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| posted on 30/5/09 at 06:47 PM |
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quote:
Originally posted by MikeRJ
quote:
Originally posted by mr henderson
quote:
Originally posted by MikeRJ
This has been covered dozens of times in the past.
Tiny bit of exaggeration there, do you think?
No I don't. Look back through the archives if you can be bothered, it really has been asked many times before.
I did, and found many different opinions. Are you in a bad mood or something?
John
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britishtrident
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| posted on 30/5/09 at 10:58 PM |
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quote:
Originally posted by snapper
Won't fail MOT if the power steering pump is not fitted.
The Sierra ratio is about 2.7 , the power steering rack is 2.4.
To use a power steering rack as a quick rack take off the flexi pipes, connect the fixed tubes on the rack together with one bit of flexi pipe,
before connecting both pipes together add some power steering fluid, keeps things lubricated.
Instant MOT Failure
Because this trick was exploited to get unroadworthy vehicles through MOTs a specific MOT rule clarification was made on this a few years back --
if you have a powered rack it has to function as powered rack
This applies also to brake servos ---- if you have a brake servo it has to function as intended.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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MikeRJ
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| posted on 30/5/09 at 11:11 PM |
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quote:
Originally posted by mr henderson
I did, and found many different opinions. Are you in a bad mood or something?
No, quite a good mood as it happens. Just pointing out the facts.
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mr henderson
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| posted on 31/5/09 at 06:03 AM |
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quote:
Originally posted by MikeRJ
quote:
Originally posted by mr henderson
I did, and found many different opinions. Are you in a bad mood or something?
No, quite a good mood as it happens. Just pointing out the facts.
You are Mr Cross-patch grumpy pants, AICMFP
In any case, to make what you said a 'fact' there would have to have been at least 24 threads on the subject, and I think you will find
that that is not the case, if you can be 'bothered' to search.
Quite honestly, I am surprised at your attitude, Locostbuilders is the virtual home of repeated subjects (and threads in the wrong sections!), and it
really doesn't hurt anybody, also new people join the forum all the time, and any one of them might have something useful to say about the
subject.
John
PS, I must confess to having a quick search to see if I could find any threads you had started which were on repeated subjects, but couldn't
(within a reasonable length of time) find any that you had started? Is this true? Do you not start any threads?
Starting threads is also a contribution, if nobody does it then we will have nothing to discuss, and therefore no forum.
Go on, ask a question about something, surely there must be something you don't already know?
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NS Dev
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| posted on 31/5/09 at 09:15 AM |
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Right, back on track for a mo!
I looked at doing this many many years ago (well, 1997) on my self built RWD pug 205 rally car which used sierra struts and rack.
I thought I could use the sierra pas rack as a quickrack with no fluid connections and the piston machined off the rack bar.....
It certainly did work, BUT I didn't like the look of the torsion valve, and there was no apparent way of dismantling it to make it rigid. It
doesn't twist much at all, but it bothered me so I just fitted a sierra quickrack kit into a normal manual rack and used that (they are only
cheap anyway)
There you go, a paractical answer, if not one that will solve your query!
I would go for an electric pump. I know of a LOT of autograssers using either those, or electric assisted columns like the fiat and corsa ones, on the
class 6 huge power front drive class cars with very tight diffs.
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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