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Sierra's with PAS/ABS - potential issues?
paul the 6th - 9/12/08 at 03:00 PM

I'm still on the lookout for a decent donor but was just wondering about the above - if I pick up a donor with power steering, does it really matter? I'd have thought it would be as simple as just dropping the power steering pump and any other associated bits out of the steering system? Or do racks with PAS have issues when they're left un-powered...

Also, with the abs - what's the crack with that? I know it would be ridiculous to have abs on such a light vehicle so is it possible to adapt an ABS system to become non-ABS?


Mr Whippy - 9/12/08 at 03:06 PM

No you can’t use the ABS components as non ABS

The power steering rack won’t normally fit in a 7 unmodified as it will be to wide so you’ll need another rack plus the MOT/SVA guy will be less than impressed if you fit one and not even have it connected to a pump as it might seize in the future also the steering wheel will be almost imposable to turn as the gearing is totally different


mookaloid - 9/12/08 at 03:27 PM

quote:
Originally posted by Mr Whippy
No you can’t use the ABS components as non ABS




I think most people don't seem to have a problem using sierra brakes designed for ABS with actually using it.

you won't get away with a power steering rack though....

Cheers

Mark


mcerd1 - 9/12/08 at 03:27 PM

the ABS will mean that you should have rear discs and the larger fronts (260mm discs with bigger calipers)
that shouldn't be a problem, but you'll have to pick an aproprite size of master cylinder (/cylinders + a balance bar)

and you could always get a rack from somewhere else....


jacko - 9/12/08 at 03:33 PM

My donor had abs fitted and i did not use the abs part and i used a master cylinder off a non abs car you don't need a balance bar


Mr Whippy - 9/12/08 at 04:08 PM

obviously I was referring to the ABS master cylinder...


paul the 6th - 9/12/08 at 04:11 PM

cheers for the replies guys - im still learning which bits will match with which other bits, and what will work with or without the said bits....

and thanks mookaloid, you'll have to pop down soon - welder tomorrow


mcerd1 - 9/12/08 at 05:51 PM

quote:
Originally posted by jacko
you don't need a balance bar

I only ment that you could use 2 master cylinders and a balance bar - I didn't mean to suggest that you'd have to get one....


paul the 6th - 10/12/08 at 10:07 AM

quote:
Originally posted by Mr Whippy
..... the steering wheel will be almost imposable to turn as the gearing is totally different




that's exactly what I was looking to find out in my OP, I just wasn't sure how to articulate it or what kind of mechanical components would vary between pas and non pas...

I don't have any mega in depth knowledge of steering racks or different braking systems (abs vs. non abs) so building a roadster is as much a learning exercise as it is about having a nice light moderately powered home built "sports car"... in other words, thanks for all your advice so far and please bear with me if I sound clueless


paul the 6th - 10/12/08 at 10:09 AM

so am i right in assuming that the only real difference between an abs and non abs system is the master cylinder? i.e. the abs has some kind of pump to pulse the pressure when the wheels lock?

If so, is it as simple as mentioned above - just swap mastyer cylinder for a non abs and job done? thanks again


colley101 - 16/12/08 at 08:22 PM

I'm building a locost based on an mx-5, planning on using the power steering rack off that but without the pump attatched.

Why would sva have a problem with this?

No more likely to go wrong than a normal non-power steering rack and it gives a ratio of 2.8 turns lock to lock so won't be too heavy at all in a 7. Its also narrow enough for the wishbone lengths I'm using so bump steer isn't an issue...


Vindi_andy - 17/12/08 at 09:10 AM

I too am using the calipers from an ABS car but a non ABS master cylinder.

This replaces the ABS cylinder and distribtion box thingy (not sure what its called but had 4 pipes coming out 1 to each wheel)

On the Power steering rack side The rack will be hard to turn as it is a 2.5 turns lock to lock ratio and if you are going to use it you ned to leave some fluid in it for lubrication and link the ends out. I couldnt use it because physically it is different where the column connects.

It is taller because of the valve and it would have fouled on things.

In addition you will have to cut the mounting for the pump off the distributor bracket as it will most likely be right where the column extension needs to pass.

Been there done that fitted manual rack acquired from local scrap yard


paul the 6th - 17/12/08 at 10:38 AM

Thanks for all the replies everyone!

It just means I'll ignore any donors with both PAS and ABS (unless they're absoutely mint and for free), and instead, keep my eyes open for a non pas/non abs example.

I'm going to wait until the chassis is nearly done and then start looking for a donor I think - money is too tight to buy the steel and a cahssis at the same time atm. Thanks for all the help!


Vindi_andy - 17/12/08 at 01:59 PM

I wouldnt dismiss them out of hand. Just bear in mind you'll need a non ABS master cylinder and a non PAS steering rack when considering them pricing wise also.

In addition if you get on to the Ford sierra owners club Forum you can sell the bits you dont want.

My donor currently stands at a nett cost of £25 after selling bits and I didnt sell everything I could cos I wasnt exactly delicate stripping it out

[Edited on 17/12/08 by Vindi_andy]