1994 Clio Steering Problem

[zanteea]

I've got a 1994 diesel Clio with PAS and for some time there has been a fair bit of play in the steering (the coupling where the shaft goes through the floor) It's always passed it's MOT though and we've got used to the sloppy steering. (Might weld it up some of these days!) Yesterday, however my sister was driving the car and got a really bad scare at a roundabout. The car momentarily lost steering altogether and she only just managed to avoid an island coming out of the roundabout. Now she's driven the car quite a bit in the past and like me is quite used to the 'slop' so I don't think it was just that. I went to rescue the car (about 30 miles from home) and it drove home without any further incident. I haven't had time to get it up on stands yet but I can't see anything obvious. Track rod ends etc are fine. PAS fluid at max and no leaks.

What I'm wondering is whether there was a momentary failure pf the PAS (electrical glitch even?)

Anyone any ideas?

[spider]

PAS failure would only make it heavy, it would not introduce any freeplay. This is a bit like some say "my engine cut out and I had no brakes" , unless its a Citroen with the full hydraulic brake setup, what really happens in reality is the loss of servo assistance which makes them very heavy but they still work, but those who are not used it to will think there are no brakes available.

Back on topic:

The same is mostly true for the newer cars that have an electric motor for assistance, either on the column (these can make it heavy sometimes depending on the design if it fails) or on the rack pinion itself.

I'm not sure what is meant by "lost steering" can you get her to clarify ? Do you mean it was locked / too heavy / would not turn or that there was an eon of freeplay ?

If the track rod and ends are OK and the UJ's appear OK the next choice (I'm assuming the steering wheel splines are OK!) would be the rack itself, the pinion could I (suppose) move up slightly out of 'mesh' with the rack teeth, this would cause loss of steering completely.

[zanteea]

Although my sister said she 'lost steering' I think it must have been a case of temporarily losing power assistance and happening as it did on a roundabout caught her off guard. Incidentally my sister normally drives a Xantia and has had to drive it in emergencies without power assistance so she's actually very capable in that respect! The odd thing is that the Clio's steering immediately returned to normal and she drove it about 40 miles back home without incident.

As I say there is quite a bit of 'slop' in the Clio steering but this s deterioration of the rubber joint at the driver's feet - a known fault on early Clios and something we are both quite used to.

Today I've been inspecting the terminals on the PAS pump (hugely difficult to get at!) They could be better and I'll give them a good clean up but I see there's a wire running between the two terminals of the pump wrapped in insulating tape and with an electrical component of some description inside. I'm guessing that it's a suppressor or suchlike but Haynes seems to have no wiring diagram for the PAS system at all so I can't work out if it's OEM or added by a previous owner to cut radio interference.

Can anyone shed light on this odd bit of wiring? It looks a bit amateur to be OEM. In any case, I'm wondering if the component in question has failed thus shorting out the motor temporarily and if so would I be better removing it altogether?

[spider]

I'd agree its more likely that the assistance was lost. Some designs of the electric assistance can be heavy, this is even more likely if (as I see in this case) its just an electric pump. No different to a belt drive one if the belt comes off = instant heavy.

I do not have diagrams for Renaults. However having said that both the 106 and the Saxo have a very similar setup (RHD UK models) with an electric PAS pump.

Without obtaining a diagram for these, there's a heavy relay to switch the motor on/off and its 'trigger' wire is connected to the 'charge' wire on the alternator (not on it itself, in the loom area) , the reason being that this way the motor will only run when the engine is running (and the battery is charging!) as otherwise it would very easily flatten the battery.

I would check for a heavy(ish) duty relay too, just follow the heavy wires from the PAS pump if you can. This would be worth inspecting too, especially its socket.

Hope that's a little bit of help.

[zanteea]

According to the (limited!) info in my Haynes the PAS pump 'is controlled by an oil pressure switch in the engine' and 'by either three or four relays depending on the model'........also......'operation of the system is complex. If any fault develops the vehicle should be taken to a Renault dealer...........'

On close inspection the electronic component that I've fished out from the loom appears to be a diode and from online research my best guess is that it's a 'snubbing' or 'flyback' diode which is designed to prevent surges of current welding the relay terminals. What I plan to try next is either sourcing a replacement diode or testing the existing one. Although I have a multimeter this line of work is not my area of expertise so if I can source an exact replacement it might be as well to replace to be on the safe side. It doesn't appear to be a common number of diode though.

I haven't got into the relays yet but will investigate - they seem to be in a box of tricks tucked under the diesel filter so that will have to come out to gain access. Why there should be as many as four of the beasties for the PAS is beyond me!

[Peter.N.]

I suppose it didn't momentarily stall?

Peter

[zanteea]

A momentary stall is maybe possible but my sister says it was almost as if the car took it into its head to go off in the opposite direction! She was making a right turn at a roundabout and had reached her exit without any problem and then the car appeared unwilling to 'left lock' to make the exit. As a result, she narrowly missed the centre island on the entrance to the exit road. It seemed to take a huge effort to force the car back onto left lock. Yet she stopped some 100 yards after the exit, parked up and when I arrived about an hour later the car was perfectly OK. I even took the car back through the roundabout again to be sure. I should say that my sister is an excellent and very experienced driver so I am fairly certain that there was some sort of brief mechanical glitch. So because it's an electric PAS pump a short break in power might be the best (only?) explanation for such weird behaviour. I can't think of any other fault in a steering system that would be capable of disappearing as quickly as it came.