Afternoon all,

Had my car on the track yesterday. On the last lap, I couldn't engage any gears unless I exactly matched the engine revs. I got back to the pits ok, but couldn't get it out of gear and the car crept creeping with the clutch fully depressed. Stopped the engine, took it out of gear fine, started it again and the pedal was very slack for the 1st half of travel and then started to engage. It was as if it was only half engaging.

I checked the Pentosin resevoir in the front and it was totally empty, with a small leak under the car in that area. I managed to get it to my mechanic by starting in 2nd/3rd gear and changing by matching the revs, which was fairly uneventful.

What do you reckon? (it was fine up until the last lap, so could it just be a burst pipe or maybe something more sinister?)

I don't quite understand the connection or difference between the front resevoir and the one in the engine bay, other than one is for the hydraulic clutch and the other power steering. Is that it?

 

Front reservoir is for line between clutch master and slave cylinder. reservoir in engine compartment is for steering and clutch slave cylinder. Power steering pressure line goes to slave cylinder and assist slave cylinder.

It sounds like master line is broken or master cylinder is broken. If you have to change slave cylinder I recommend to change pressure accumulator same time.
It's connected to cylinder...

 

There was a leak just behind the front left wheel, ie right under the resevoir, whereabouts are the master cylinder and slave cylinder?
I'm hoping it's just the line between the two. Hopefully the mechanic will get a chance to look at it this week and let me know.
What are $$$ implications of slave/master cylinder failure? If it was the slave cylinder then would I not have power steering issues too?
Thanks.

 

The fluid behind the left front tire is overflow from the small Pentosin reservior due to a bad slave cylinder. 0% chance of line failure, however hoped for. Power steering will be unaffected, as the fluid level doesn't get that low in back. Part is about $800 US, labor will probably be substantial unless you DIY.

 

Master cylinder is behind the clutch pedal and slave cylinder is above the transmission.

Was the small reservoir wet from outside?

There is no overflow pipe anywhere. If internal leakage occure in the slave cylinder, only natural way to overflow is the small reservoirs cap and the reservoir it self should be full to the brim.

 

The resevoir was dry from the outside and totally empty.

How much labour involved with changing the slave cylinder?

 

It took me all day, a sharp tech might get it done in 4-5 hours. The failed slave allows the power steering pump to transfer the fluid to the front reservior where it overflows and drains out of the bottom of the trunk behind the left front tire. Normally the reservior would be full, but perhaps it occurred long enough ago that it emptied and dried out. My clutch still operated normally when I noticed the overflow and leakage. I'd guess the if the problem went on long enough for the clutch to quit working, that might explain the empty reservior.

 

Hi Don,

did your mechanic look your car already?

 

Just spoke to him. He said all it needed was a refill of fluid and bleeding. No leaks apparently.

I find this hard to understand, but I do trust him so hopefully all is well.

I just have this niggling thought in the back of my head.........but from what I can remember it was totally dry, on the outside. I thought I saw a leak behind the tyre but that could have been water/condesation from the A/C.

Time will tell.

 

I had *exactly* the same problem about a month ago. Had the car on the track at Goodwood for the day. Driving back to London the clutch felt funny, notchy, a little trouble engaging first gear at stop lights, etc. When I parked it the clutch pedal was totally slack for the first half the distance to the floorboard. When I tried it in the morning the pedal was totally on the floor and no gear could be selected. But depressing the pedal did disengage the immobilizer, so the car would start. But that's all it would do. When looked at by my mechanic he found the reservoir in the trunk bone dry, but there was absolutely no evidence of any leak - anywhere! No stains around the reservoir nor the lines, or in the trunk, or under any of the carpets or any of the other places he would have expected to find them. Nothing. He really couldn't explain it. So ... he refilled the resevoir, pumped it up and --instant clutch action. Told me to keep a very careful eye on it, which I've been doing. Since then the level in the reservoir hasn't moved.

 

Aliens have been known to sweep down in their search for dirty Pentosin. Keep a pryamid shaped aluminum foil cover on your car to ward them off.

 

Aliens...I can't think of any other explanation.

Although the mechanic did say that if the level was very low prior to the trackday it could have boiled off.