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[STEMO]

And the screenwash is rusting the interior floor and electric gubbins  away nicely

FTFY 

Touché, young builder 

[Andy B]

The electro hydraulic system is pretty much identical to the traditional one... Only difference is that the pump is electric rather than belt driven... Pump is moved to the rack for convenience/packaging purposes

Pump or motor?

The electric assisted steering on my Smarts don't have a pump (just been to look at my ML and that appears to be electric only too which is probably how it steers itself when self parking)

Motor driven pump assembly

It was  genuine question .....  As above, my Smarts are just electric ..... the motor is on the rack though, but as STEMO has posted, sometimes the motor is on the column itself like my Daughter's Fiat used to be

[Andy B]

I know that when the 'fan belt' went on my diseasal Astra G, the steering went really really heavy.

[terry paget]

astra H is electric pump to pump hydraulic oil on most models same as astra g
astra F had a belt driven pump like the omega

Astra H like this clicky



if the rack or pipes leaks ,the reservoir may need topping up short term

remember you have a spares car Terry

Thanks Dave. I saw Ben try to start the car first, engine was in gear. He then put it in neutral, started the engine, twice tried to drive way, then stopped the engine, and fetched me. Suspecting power steering slow to operate, I started the engine, tried to turn the steering wheel, succeeded with effort, after 5 seconds power steering kicked in, then all was normal. I think I should check the fluid level and look for leaks. Is access from above or below? Is there a level line on the reservoir?

[Doctor Gollum]

Min and max bands clearly visible in that picture...

[Andy H]

Lots of cars prevent heavy electrical loads (eg the rear screen heater) from operating until the alternator gives an OK signal

Does the Astra H do this with the power steering? Was the difficulty starting caused by a tired battery ? and did the steering come to life once the alternator had put a bit of charge back into the battery?

[terry paget]

My thanks to all for comprehensive advice. I read in Haynes that the Vectra may have either electro-hydraulic or electric power assistance, and the Rover Streetwise has traditional PA, hydraulic driven by belt from crankshaft pulley.

My Citroens had hydraulic PA and suspension, my Peugeot 504 and all my earlier cars lacked steering PA. Now even small cars have it.

[dave the builder]

starting the car with it in gear does spank the battery a bit 
so

Lots of cars prevent heavy electrical loads (eg the rear screen heater) from operating until the alternator gives an OK signal

Does the Astra H do this with the power steering? Was the difficulty starting caused by a tired battery ? and did the steering come to life once the alternator had put a bit of charge back into the battery?

is quite possible 

don't know for sure because I always have my foot on the clutch pedal and wiggle the gearstick through habit on a manual car ,and a car struggling to start with a duff battery I just swap the battery

with astras and other small 1.2 - 1.6 engines a little warm up and few revs (whilst adjusting mirrors seat)before you load the engine or try and drive off
then a creep forward and try the brakes ,
just a routine I got into
OCD 

[TheBoy]

and the Rover Streetwise has traditional PA, hydraulic driven by belt from crankshaft pulley.

All Rovers had the traditional belt driven hydraulic pump, as essentially all development stopped in the early/mid 90s when BMW took over ARG/Rover from British Aerospace.

So although the Streetwise was launched into the era of electro-hydraulic PAS, it retained the older system, exactly as it was on the first K series 1989 Rover 214.


The primary reasons for going to electro-hydraulic from belt driven pumps was efficiency and easier packaging.

The primary reason for going to electric motor PAS is for software controlled steering (self parking, lane deviation warnings, and full autonomous)…   ...although as it becomes more popular, this will likely also make it the cheapest ultimately.  The motor can be column mounted or rack mounted, depending on space available.

[terry paget]

Lots of cars prevent heavy electrical loads (eg the rear screen heater) from operating until the alternator gives an OK signal

Does the Astra H do this with the power steering? Was the difficulty starting caused by a tired battery ? and did the steering come to life once the alternator had put a bit of charge back into the battery?

Thank you. I did not know that. It describes exactly the Astra's behaviour. Come to think of it, some while ago my sister called me to look at a similar problem on her Meriva, when I got there I could find nothing wrong with it.

[BazaJT]

I know Nissan Micras had[still have?] electric power steering and it took a second or two after starting before you could hear an audible "click" from the steering column letting you know the system had become active.

[Doctor Gollum]

The electro hydraulic system is pretty much identical to the traditional one... Only difference is that the pump is electric rather than belt driven... Pump is moved to the rack for convenience/packaging purposes

Pump or motor?

The electric assisted steering on my Smarts don't have a pump (just been to look at my ML and that appears to be electric only too which is probably how it steers itself when self parking)

Motor driven pump assembly

It was  genuine question .....  As above, my Smarts are just electric ..... the motor is on the rack though, but as STEMO has posted, sometimes the motor is on the column itself like my Daughter's Fiat used to be

Trolley has an electric pump mounted along with the hydraulic reservoir on the rack casing...

[terry paget]

In answer to my original question, I conclude the PAS may be by powerful electric motor, on rack or steering column, controlled by ECU using data from ABS and steering wheel position. I wonder how powerful - what size fuse and cables?

[Doctor Gollum]

Between the manual and removing the cowling, it should be obvious

[TheBoy]

In answer to my original question, I conclude the PAS may be by powerful electric motor, on rack or steering column, controlled by ECU using data from ABS and steering wheel position. I wonder how powerful - what size fuse and cables?

The fuse is usually large - 40A or even 60A.  What it actually pulls (max) is probably nowhere near that, as we all know the fuse is there to protect the wiring only.


I looked at Astra-H PAS details.  2 types fitted, depending on engine. On lighter engines, its the same TRW electro-hydraulic fitted to some later Astra-G models.  No integration with other systems.  On heavier engines, its a ZF system, and sits on the HS CAN, and obviously chats away to all the other systems, enabling further enhancements and features.


Obviously, TRW is now part of the ZF Group, just to confuse everyone


The docs I had to hand only didn't cover the refresh, or Astra-J/K, so didn't see any info on the pure electric stuff.