New car, ABS light plus dead clutch plus steering wheel shuddering?

[galenmoloney]

I just bought a 1990 Carrera 2 with my Dad which I am very excited about, the bodywork is nigh on perfect (impossible here in Ireland/the UK) and the engine pulls fine with limited oil leaks, car has good Porsche service history up until relatively recently. The car was in a garage for 2 years so there are some issues (I got a very good discount so hope these are priced in).

The car has no MOT so I test drove it for about 30 minutes around the sellers farm. When I set off the ABS light and warning signal came on.

Car drove fine to begin with however the brakes felt very notchy and very hard (maybe the ABS was engaging too soon). However car started to go for 10 minutes or so where the steering wheel was shuddering regardless of the surface or speed I was travelling at. The fact that the shuddering was on and off would indicate it wasn't the tracking. Also I could hear the brakes squealing. The brake pedal seemed to get progressively harder. It would seem the ABS was being triggered. The seller also told me that he had instances where the clutch went completely dead (flat to the floor) when he was testing it and then it was live again the next day.

In researching what the main issues might be on this great forum (this place was fantastic for my last car!) I found out the following:

There is a brake booster which assists with the braking, without it the pedal is very hard. It would seem that the brake booster may have failed somehow and that might explain the hard pedal. It may be an electrical reason, fuse 15 controls the brake booster and I believe relay 41, I am going to check these in due time (car is in Ireland with my Dad now).

The ABS light was on and it seemed to be engaging, fuse 16 relates to the ABS system and seems to be working, relay R34 relates to the ABS and seems to be in a very poor state (I will order a new one). The research I have carried out indicates that certain of the relays need to be replaced every 2 years. Other research said that the ABS is driven by sensors on each wheel indicating the wheel speeds, these apparently get clogged with iron filings from the brakes and can trigger periodically. The ABS system seems to plug into the general hydraulic system and the main components are a pump and a control unit. If the pump is triggering (even incorrectly) then at least the expensive part (the pump) is working!!!

The reservoir seems full however the fluid looks off. I will get a mechanic to replace this.

Has anyone had these symptoms before? particularly the dead clutch and hard brake?

BTW here she is below, not the fastest way for her to get home but certainly the safest!

[mb911]

I have the abs light but I have been driving it like that for a while I think it just is a nature of the beast though I am trying to diagnois it as well I may try the relay as its funny you say they need to be replaced every couuple of years I have not heard that . the clutch thing sorry I have not had that experince as of yet.

[redturbo911]

My ABS light was on checked the fuse changed it and simple fix for me hope its that simple for you. Good luck.

[LouZ]

You note that the ABS wheel sensors can pick up iron filings...very true!!

It is a simple task to pop the plastic disks on each wheel hub and inspect, and clean the filings off!

[f3nr15]

Your brake problems sound like 2 separate issues:

1. Wheel sensors or ABS relay or ABS controller (also worth looking at the positive power supply for the ABS which has its own battery lead/terminal)

2. Brake booster (or master cylinder?)

It's worth posting on the Rennlist 964 discussion also, as there are more 964 afficiondos there.

Best of luck!