Road Trip Clutch Troubles (240SX): Grassroots Motorsports forum: Grassroots Motorsports Magazine

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Feb. 14, 2010 11:30 a.m. PHeller HalfDork

So in Valentines spirit I drove 5.5 hours to Erie, PA to visit a lovely lady friend of mine.

About half way through the trip, I started noticing that my car was not going in and out of gear correctly. Upon further inspection (and another 2 hours of driving) I found that the clutch pedal was losing pressure.

Now that I made it to Erie and the car has sat for a few hours and sufficiently cooled down, it seems as though it back to normal, but that's only at first non-running glance.

Lets say that this has something to do with heat, and the long drive at sustained high speeds (75-80) is messing with the clutch system...is this a likely possibility?

If its not heat related, what else does it sound like?
Feb. 14, 2010 11:51 a.m. P71 SuperDork

Hydraulic clutch pedal (master/slave/etc) or mechanical (cable/rod)?
Feb. 14, 2010 11:52 a.m. PHeller HalfDork

Hydraulic.
Feb. 14, 2010 12:00 p.m. jrw1621 Dork

check the fluid level in the clutch reservoir. it loks like the brake fluid resevoir but smaller
Feb. 14, 2010 12:22 p.m. porksboy Dork

Bleed the air out of the line also. A friend had the same problem a last year ago on an Acura. Shop told him new clutch time. I said put fluid in it and lets bleed it. Has been fine for at least 6 months.
Feb. 14, 2010 12:43 p.m. 4cylndrfury SuperDork

how old is/are the soft line(s)? I had about 12 year old brake lines get mooshy on me simply because the soft lines were old and beginning to get worn out and would expand slightly when Id hit the brakes, causing less pressure to be applied at the caliper/drum. Some new lines and a half hour of fill, bleed, repeat, and I had fancy new braking...could be the same on a decade plus cars clutch operation.
Feb. 14, 2010 2:07 p.m. PHeller HalfDork

These aren't mushy, the pedal becomes non-existant. Almost as though its not doing anything. Someone on NICO suggested the slave cylinder.
Feb. 14, 2010 2:12 p.m. EvanB HalfDork

Sounds like the same symptoms as my Miata when the slave was leaking and ran out of fluid. Try filling up the fluid and maybe bleeding it if necessary.
Feb. 14, 2010 2:24 p.m. P71 SuperDork

Probably leaking and probably at the slave. Try to empty out the master with a rag and refill with fresh DOT4, pump furiously to bleed it a bit.

The other possibility is that you are boiling the fluid. Lots of LS1's and 05+ Mustangs do that drag racing. It's just regular old brake fluid in there and nobody ever seems to flush it.

The fix either way (for now) is to refill and pump. Buy a new slave (and a SS clutch hose if you can) when you get back.
Feb. 14, 2010 3:24 p.m. PHeller HalfDork

Master cylinder reservoir is full.
Feb. 14, 2010 3:35 p.m. BobOfTheFuture Reader

Id say it heat soaked, as weird as that sounds with you up near Erie in winter. As a quick fix you can use a rag/shop syringe to empty the reservoir a bit, with out exposing the ports at the bottom, Fill with fresh fluid; then bleed if you can. When you have time do a full flush/bleed.
Feb. 15, 2010 9:07 a.m. PHeller HalfDork

the blackened residue left by the old fluid made me THINK that the reservoir was full, but alas it isn't. Popped the top and bone dry. Stuck some fluid in it, taking it to a shop to see if they can't slap a slave cylinder on it asap.