Clutch pedal snaps-to ends of travel

[jibduh]

Finally getting back into the TII, and while Felix's doritos on a stick are an issue, I thought this other problem was a bit more interesting:

Admittedly, I?m getting in over my head again, so I thought some fact finding might be useful after the fact.

The car has apparently been sitting for quite some time. The clutch is hydraulic, and looked low or empty before I poured in some fluid in a long shot to have everything miraculously start working.

The clutch sits at the bottom of travel. Held there, as if, by a spring. Raising the clutch up to halfway and releasing allows it to spring to the bottom, again, as if by spring.

Past the half way point, closer to a quarter of the travel distance from the top, pulling up on the clutch past this point springs the clutch up. Actuating the clutch a number of times by pushing/pulling ends with the same response pattern (and I suspect is likely to have ruined whatever was left of the master cylinder?s seal). The travel doesn?t feel damped by any hydraulic fluid. I?m not too surprised by this since I didn?t go so far as to actually look for/crack the slave bleeder.

Should I be expecting a line perforated and full of rust?

Is my master cylinder fubar?

If the clutch weren?t hydraulic, I?d have thought my pressure plate gained an additional detent. Any chance something in the clutch itself is part of the problem?

Thanks for the insight, spectre everyone.

 

[Spectre]

I deliberately never learned any of the details of the Failbox known as the 405 so I don't know if it had a 'push' or 'pull' clutch action. That makes a difference in trying to figure out what went wrong.

Your first problem is going to be that the system was apparently empty. Just filling it back up isn't going to help - assuming it still seals even temporarily, you still have to bleed the air out of the system just as with brakes. Personally, I would just assume both the hydraulic cylinders are screwed at this point in time and just rebuild/replace them while inspecting the line connecting the two. If the seals aren't completely screwed yet they will be shortly after you put it back into service.

It is possible the clutch's basket or pressure plate is screwed as well, but that's a lot of labor to pull just to look at it when it may very well be just a hydraulic issue.

 

[jibduh]

It isn't the peugeot but a mazda this time. Do I have to be a 405 apologist? (probably) :lol:

I suspected the filling was a lost cause if I wasn't going to invest more than the five seconds to crack a bottle of brake fluid to pour in but did it anyways. More time in front of the computer than under the car, after all.

While I'm shooting my own foot, I'll OT my thread and ask what's the best way to diagnose a jumping tach. the 405 P) tach starts jumping around 3k, but below that while gas/left foot braking, it seems fine. nor do revs change audibly. I'm suspecting a poor ground or bad sensor (see: French electrics). does that seem reasonable? again, would rather see the simple solution before taking the trans off... then again, french electrics are only simple in the sense that they're simply crap and simple to toss in the bin.

 

[Spectre]

It isn't the peugeot but a mazda this time. Do I have to be a 405 apologist? (probably) :lol:

I suspected the filling was a lost cause if I wasn't going to invest more than the five seconds to crack a bottle of brake fluid to pour in but did it anyways. More time in front of the computer than under the car, after all.

While I'm shooting my own foot, I'll OT my thread and ask what's the best way to diagnose a jumping tach. the 405 P) tach starts jumping around 3k, but below that while gas/left foot braking, it seems fine. nor do revs change audibly. I'm suspecting a poor ground or bad sensor (see: French electrics). does that seem reasonable? again, would rather see the simple solution before taking the trans off... then again, french electrics are only simple in the sense that they're simply crap and simple to toss in the bin.

I missed that it was the Mazda, but the same still applies - check the hydraulics first. You're going to have to bleed the system down before you can get anywhere with seeing if it works or not.

The Fail Oh Five tach jumping around is going to be caused by the system picking up more ignition events than it's supposed to. Tachs of this era run off the ignition system in general. I'd look at a bad ground and perhaps bad wiring routing, shorting or degraded shielding. But first I would check to make sure I hooked up all the wires to the coil correctly.

 

[jibduh]

Sorry, I wasn't saying the problem's different since it's a mazda over a peugeot but instead, defending the honor of a car that led to the surrendering of the US market. ...followed shortly by describing problems of said car.

Is it possible due to the new coil I put in not being entirely compatible? Would that have been an all/nothing thing where the car wouldn't have started at all if it wasn't compatible?

Or more likely that frayed wire ground I decided was 'good enough' since iw was working before, or that *crack* heard of the insulation when I pulled off the connector initially on the coldest day of the winter...

...nah

Might not hurt to go back and tweak them a bit, I'll admit. And I wasn't looking forward to dropping the trans, so I'll poke at the coil area again.

Could the additional signals translate to additional firing of the plugs and knocking? (basically, I'm asking if driving it is likely to do any more damage than being French is doing to it.)

 

[Spectre]

In order: No, yes, that would do it, so would that, yes since the coil fires when the secondary is switched (shorted) to ground.

To be explicit: Every time the secondary shorts out to ground the main fires a pulse down the ignition wire. With everything that implies. Your wires to the coil *must* be properly insulated and isolated.

 

[jibduh]

Haha, it seems I've slipped back into asking too many things at once.

Insulation is straightforward enough. Broken into its individual wires, I should be able to work them out. I don't plan to let the smoke out of another harness just quite yet...