Abs

[Guest elwe]

Whats the general opinion on the possibility of using a donor with ABS and keeping the ABS system active?

 

The only possible problem I can see is that electronic ABS is programmed with the quickest the vehicle can slow. If any wheel appears to be slowing quicker it assumes it has started to lock up. Will a 2B stop too quickly for a Sierra ABS controller? Is the Sierra ABS mechanical?

[Guest chris brown]

I think you would have problems finding somewhere under the bonnet to put it (could go where the battery is supposed to be ) also there is a fair amount of wiring involved seem to remember this topic has come up before do a search you may get some good gen

[Guest grahamdale5]

I have incorporated the wiring in my loom but the main problem is that the 'servo' assembly is too tall to fit under the bonnet. Just sold the lot on e-bay to stop me thinking----if only!

[Guest paul mercer]

I went through a hole dilema about whether to fit the abs or not. Having had it on most of my recent cars I decided that i'd love to fit it. I found out that it wouldn't fit under the bonnet, and the wiring for it is awful. There was only one decision that made any sense!!

 

 

So anyway, I went the other way and decided to fit it. The wiring was a pig, but it is a seperate loom with only about 7 wires that you have to worry about. i spent weeks going over the manual and the old loom to figure out what did what. I'm a qualified vehicle electrician, so it shows how tricky the wiring is. It looks simple, but the loom is really wierd.

I have got the secret wiring diagrams somewhere at home showing you what the wires actually do. This should make it nice and easy for you. Maybe i'll even dig them out and post them on here somewhere.

As for the fact that it pokes out the bonnet, i made a bonnet scoop to cover it.

 

I would definately fit the abs. It is really usefull. It's an electronic system that doesn't care how quickly you slow down. It compares the speed of all wheels and reduces braking forces when traction is lost. Be warned though. This system is the most potent that ford has ever made, so it does lock the wheels up very easily if you're not carefull (well it would without the abs, but i think you get the idea.)

 

Hope this helps.

 

PAul

 

On a seperate note, my abs stopped working last week. any ideas anyone? ha ha.

[Guest elwe]

I take it your peddle assembly is fitted in the normal position. I.e. quite high?

 

Since I am going to be using a Rover V8 I was thinking about a custom peddle box. I wonder if I can lower the abs unit down by using floor hinged peddles? But then I don;t quite know where the exhausts will end up at the minute...

 

I suppose I should give up on the ABS idea but I might just get an ABS doner anyway, I can always change back to a standard master cylinder.

 

I bet the ABS ECU does have a maximum decceleration rate in it. It should be looking at the wheel speeds every 10ms or so. Thus the wheel won't have locked up when it releases some braking force.

 

For instance:

It looks at the wheels and they are all doing 70mph.

It looks at the wheels and they are all doing 69mph. This is OK.

It looks at the wheels and the rear ones are doing 68mph. The front ones are doing 60mph. This means the front ones are locking up. The car can't slow by 9mph in 10ms. Some breaking force is released.

It looks at the wheels and they are all doing 67mph.

 

If the car is good enough to stop quicker than the ABS units maximum the ABS unit will actually make the car brake slower.

 

The problems with comparing the speeds of the wheels are:

1. What happens if all 4 wheels lock up.

2. What happens if one wheel is off the ground and spinning fast when you hit the brakes.

3. What happens if the tyre presures are very different and thus the rolling diameters are very different?

[Guest paul mercer]

Ok, i accept your points.

 

But, The ABS does work on hoods, as i've got it on mine.

 

The pedals are actually fitted 25mm higher than the original holes, so that the turbo didn't touch the master cylinder. There is quite a lot of plumbing to do, so if you are going to fit it in the future, make sure you leave space.

 

Paul

[Guest elwe]

The ABS does work on hoods, as i've got it on mine.

Thats the confirmation I was hoping for. Now to find an ABS doner.

 

A 2l DOHC Ghia I think as I won't be using the engine. Are there any other sierra's that had ABS?

[Guest paul mercer]

the xr4x4i had the same abs system, and the cossie had mostly the same system, although there were a few differences i think. When you fit it, you'll see from the haynes manual that depending whether the abs was from the sierra or the granada, the fitment was different. On teh sierra, there were 2 units bolted together. You need to split these like on the granada. There's only 1 high pressure hose that needs forming and 1 low pressure hose, that is about 10mm i think. This is available from lots of places. Check the dimension though.

 

If you need any pics, let me know, or i'll be at detling.

 

PAul