ABS identification

[Eldavo]

I've been convinced my car has ABS since I got it but recently I've not been too sure whether this is the case or whether it's broken. After doing the gearbox oil today I took the car out for a spin and practiced an emergency stop on a deserted bit of business park which resulted in the nearside wheel locking up.

So, how do I find out whether I've got ABS or not first of all? When I can confirm it's existence or lack of, I can start looking at fixing it!

Secondly, there are 2 sets of Goodridge braided brake hoses available, S1 and S2. Are these only limited to the S cars and Turbos or will one set be right for my car too?

Thanks, David.

 

[pauljmcnulty]

I thought all the 2.7s had ABS? Easy way to tell is to turn the key until all the warning lights show, the ABS one is very obvious.

 

[Eldavo]

Dammit, looks like it isn't working - and Clarks Garage has nothing on ABS so any ideas?

 

[Dockrell]

David,
I have a 2.7 944 and they do have ABS.
The components of ABS are:
Wheel Speed sensors - you should be able to see the front ones easily.
Control unit - under the carpet on the outside of the drivers footwell - you should be able to feel this.
Pump assembly - under the offside wheel arch under the plastic liner.
Relay in the fuse box (also one on the pump assembly) and fuse- should be easy to spot and to check.

When I purchased my 944 there were no warning lights showing but the ABS was not working because the pump motor was rusted solid.
A previous owner had taken the bulbs out of the big warning light and ABS warning light and stuck black tape over the holes!

My local independant specialist identified the problem as the pump assembly and fixed it for about 2 hours labour. I managed to source a working pump assembly from eBay.

Mike

White 2.7 automatic

 

[Eldavo]

Thanks Mike, will start with the easy culprits first and then work my way through the list.

 

[Eldavo]

Hmmm, everything "seems" in order and I can hear the relays on the ABS pump go click-click when the ignition is turned on and no warning light, but no ABS.

Is there an easy way to test the pump, perhaps applying a voltage across it or something?

 

[Dockrell]

David,
There is a great deal of information on the ABS system, together with things to take care with when ABS is fitted, in the workshop manual.
You can get 'ripped' off copies of the Porsche manuals on eBay for a few Pounds.
Whilst I should not condone the copying of this information I find them really useful.

Mike

White 2.7 automatic

 

[Eldavo]

I've been looking through the workshop manual and it would seem that all models share the same ABS system. There is mention of a testing tool but I've no idea what it is and googling it doesn't yield much.

I'm going to remove the arch liner and fiddle with the pump a bit as logic tells me that any fault on the sensors would light the dash warning. I suppose that my OPC will have the correct diagnostic tester and will happily fault find, for a price!

 

[chrisg]

Dear Both

Regarding ABS - I've got a pump and brain unit from an S2 for sale if you need spares ?

Yours

Chris

 

[Eldavo]

Cheers Chris, hoping to get a look over the weekend and will take it from there