The suicidal clutch cable

[nametooshort]

So, there is one issue that's really annoying me about the 305. Its a really cool car, very practical, much nicer to drive then a diesel Passat of that age, etc.

But the one problem that's been plaguing this car are clutch cables. In my few months of owning it, it has averaged more then one cable per month.

The plastic mounting flange where the cable mounts to the firewall always snaps off.

I talked to a few people (one of them was an ex taxi driver that used to run Peugeots all the time) and the consensus seems to be that these cables are indeed a pain in the ass, and were the Achilles heel of an otherwise very practical range of cars.

The taxi driver guy said that back in the day, the usual fix was to take the cable to a machine shop and get them to make an alloy mounting flange to replace the plastic flange. So I was going to do that, just make a little alloy fitting which will fit to the end of the cable. Because the cable has a non-removable end, it would have to be made of 2 halves and clamp onto the cable. Wouldn't really be a problem to make something like that.

However, then I randomly had a thought. I remember reading in the manual that all the models that used the XUD engine had clutch adjustment data, except the Talbot Horizon, that's odd, could it have a hydraulic clutch?

Then I remembered that I saw a Talbot Horizon clutch cylinder on ebay. So from that I assumed that the Talbot Horizon had a hydraulic clutch.

I think the Horizons and 305s with XUD engines shared the same transmission, so I started to look for a possible fitting that would have been used for a slave cylinder on a Horizon, but redundant on a 305, and found two M7 bolt holes and what looks like a mounting point.



A Talbot Horizon cylinder appears to look like this:



The positioning makes sense. If the cable lever and pushrod was removed, it would make sense for a slave cylinder to fit there and push the clutch lever directly. The hole dimensions line up too, so I assume this is indeed where the cylinder would have mounted on models with a hydraulic clutch (horizon only?).

I also found a Horizon slave cylinder (someone I know had a NOS one, but it won't be here for a few days).

The Talbot cylinder has a bore of 25.5mm apparently, and I got someone to measure the stroke of the clutch lever/pushrod on my Peugeot while I operated the clutch, and they measured that to be 14mm give or take. So from that you can work out that with a stock Talbot slave cylinder it will take about 7.15cc of fluid to completely operate the clutch.

A lot of older clutch master cylinders are 19mm, and for one of those to pump 7.15cc of fluid, it needs a stroke of about 25.2mm.

I studied how the clutch pedal system works on my 305. Of course, a cable needs to be pulled, so it has a angled lever on the pivot. Here is a very simplified illustration of how it works:



So I started thinking how its possible to mount a master cylinder in this area.

There is no room above (brake servo), not really any room to the sides (brake pedal and other stuff on the way) and not much room below, BUT, there is room straight forward. So, I figured, what if I made a slight mod to the firewall insert, and fit the cylinder there, being pushed directly by the pedal rather then pulled by a pivoted linkage. Would look somewhat like this:



So then I measured the stroke of the pedal at that point, and as it happens, the stroke appears to be about 32mm or so, which is perfect, because if it's 32mm from its top stop to the floor, then there is comfortably 25mm + errors, so that would work.

I am now thinking of actually doing that, and fitting a hydraulic clutch, to solve this stupid clutch cable problem once and for all.

Any opinions?

[spider]

Interesting read.

Cables can break due to heavy clutches but its not that simple as you have seen.

If looking for donors, the 206 diesels (RHD only as far as I know) have hydraulic clutches, I know some of the 406's do too but I was thinking the 206 is probably nearer the Horizon than a 406...

[Lighty]

Think I would replace the clutch first, if its breaking cables that often it must be very stiff.

[nametooshort]

The clutch is reasonably new, and I can't find anything wrong with it.

Its not actually breaking the cables themselves, its the plastic fitting on the end. Apparently, according to all the old taxi drivers, this was so common that local engineering companies anywhere where there was a big peugeot taxi/company car presence used to actually make kits to replace that part with an alloy part.

[citronut]

what used to be the cause of this on BX's was incorrectly fitted cables by the likes of the 'breakdown recovery operatives' for want of a better word
used to not fit the plastic feral at the bulkhead end correctly so the inner would chafe on the outer mounting bracket,
hence it would wear through rapidly

[Homer]

There used to be lots of info in the Citroen section on avoiding broken clutch cables. Certainly 1600BX's were notorious for it. I seem to remember the thrust release bearing being one culprit.

Also I have very bad memories of the hydraulic clutch on the Talbot Horizon, I wouldn't want to base anything off that system. You might be swapping broken cables for worn out clutches.

[nametooshort]

Oh, how comes? What was the problem with the Horizon system? Worn out clutches on hydraulic systems are usually caused by the master cylinder pushrod clearance being incorrectly adjusted (I believe this is somewhat more of a problem with British-style systems, where the pushrod is held to the master cylinder with a circlip, and therefore has no adjustable clearance gap).

[nametooshort]

Interesting...I was reading some literature, and it seems the hydraulic system from the Talbot goes back to a car called a Simca 1100 (I don't really know what that is, but I found a reference in an old parts catalog and therefore looked in my big cupboard of old books and found a manual for one).

The original Simca system used the same cylinder, but with an adjustable pushrod, and its adjustment data being quoted as 1.0-1.5mm cold @ operating arm, which makes sense. The Talbot uses the same cylinder but with a fixed pushrod, presumably adjustment being expected to be pre-set.

Maybe that is why you had problems with yours, it would make sense for a system like that to cause problems related to not releasing the clutch fully.

Mine however will have adjustment, like the Simca style system.

[citronut]

look here

http://tinyurl.com/ckzut6m" onclick="window.open(this.href);return false;