R&R Clutch Master on SPF GT40

[Mark]

Clutch pedal totally dead (happened real fast) with no leaks at all around clutch slave or along clutch line to master (as far as I could tell). Clutch reservoir checked and was almost empty.

So, before I start pulling apart A/C housing to get to pedal assembly (note: have changed throttle cable a couple of times and both were truly a painful experiences), any suggestions on what to try before jumping on master cylinder?

If it turns out to be master, any suggestions on easing the pain to get to it to R&R?

 

[Kevin L]

I had a master go out on me... ended up buying a new one from Wilwood. In my case it went nearly as quick, realized there was an issue when I put clutch in, got three more pumps and it was gone. The story was that it may have sat a long time and the o-rings dried out. No idea if that was true or not.

 

[Mark]

That's exactly what happened with mine. Were you able to get to and replace master from above without loosening the entire pedal assembly?

 

[Kevin L]

Yes, I think so.. that said, it has been 10 years so my memory is a little foggy

 

[Mark]

Well, bled clutch with Motive pressure bleeder, and it worked. Must have been air in the line...right? Nope, too easy.

Got car up and running and drove it around a bit. When I cranked it to put into garage, pedal went dead. Bled it again and was able to get about halfway into garage when it went dead again. Still no leaks on ground. As I got out of car, felt left butt cheek all wet. Clearly, leak in clutch hyd line in seat area. Eventually leaks started to appear under drivers door and Girling oil can was about empty.

Since I have to replace the line in the cockpit area, any suggestions for upgrading line? I'm guessing the metal line may have been rubbed open going thru frame/grommet.

 

[Markus]

Mark,
Are you sure it leaks out of the line? Pictures?
I think to remember that that there have been lines connectors (don't recall if brake or clutch line) in the seat are close to the fire wall!? Any anybody else?
Maybe it's leaking there if you have connectors in your car....
Hope this helps.

 

[Mark]

1st pic dry coming from pedals. 2nd pic dry entering bulkhead. Leak somewhere in last three pics. Will refill res and pump clutch pedal to see if I can identify exactly where leak is.

 

[Mark]

Will verify, but looks like the bottom/lower of the two metal hyd lines belongs to the clutch. Assuming it's the one leaking, seems to me simply replacing that line with a braided stainless steel line would be the way to go.

 

[Neil]

Speaking of stainless steel braided line, be very careful not to run it against hard line as over time it can wear through the hard line due to vibration. It is best to use rubber-lined mounts to keep all the lines in place.

 

[Mark]

Thanx for data on braided lines rubbing...will watch for that during install...

Looks like it is the top steel line after all that is the clutch line...will remove hard line at the fittings on either end...measure the fittings and find a braided steel hyd line with appropriate size male fittings on each end

Probably should do hard brake line at the same time...will think about that

 

[Mark]

wrt to fittings above, anyone already know the size/thread of the fittings attached to the clutch and brake lines running along the drivers seat in the pictures?

 

[Neil]

Thanx for data on braided lines rubbing...will watch for that during install...

Looks like it is the top steel line after all that is the clutch line...will remove hard line at the fittings on either end...measure the fittings and find a braided steel hyd line with appropriate size male fittings on each end

Probably should do hard brake line at the same time...will think about that

You will be far better off in the long run to use hard line wherever possible. Use braided lines only where you need flexibility-- and use the appropriate type of braided line at that.

 

[Mark]

Installed braided stainless steel brake and clutch lines from double junction (top clutch, bottom brakes) to the left at the bottom of clutch pedal. Fittings were entertaining. At this double junction, installed two male 3an to male M10 x 1.0 inverted flare (convex cone at bottom of fitting) both top and bottom. Two braided stainless steel lines with female 3an on each end were connected to these front fittings. After try and error, found that rear fittings, adjacent to drivers seat, required two male 3an to female M10 x 1.0 DIN concave fittings (accommodates DIN bubble flare (concave) on the 3/16" brake lines coming from rear of car). These two fittings arrive from Pegasus Racing Tuesday. Then will bleed clutch and brakes and check for leaks.