Clutch Question

[Eleven]

My SV has been getting progressively worse getting it into reverse and first/second gear. Finally got very bad the other day coming home. Jammed it into first and got home via double de-clutching, rolling stops and a lot of middle finger encouragement from other drivers.
Checking the Master reservoir I noticed that the fluid level is even with the very top of the unit and looks like a bit may have spilled over. I never fill it that full.
My guess is that either the slave or the master internal seal(s) have deteriorated and pumped fluid back into the master. When I got home, btw, gave the clutch pedal a half dozen vigorous pumps and everything seemed fine.
Oh, I always use the fluid (DOT 3?) that Rick sells.
Thank you for your help!

 

[alpine_64]

Dot 4 is the usual fluid ive used... You didnt mix any silicone fluod in...that will cause seals to swell

 

[Eleven]

I may have the fluid wrong, will check. I order it from Rick rather than buy it locally. I haven't mixed and match as far as I know! Thanks!

 

[hartmandm]

Tracy,

It is interesting that the level in the clutch master reservoir is higher than the level you remember filling it to. I'm trying to guess how that might be. I think one possibility is the clutch slave was not fully retracting when you filled the system and now it is fully retracting. But I'm not sure how that would result in your symptom of the clutch not seemingly to fully engage.

What is the history of the clutch components - clutch master, clutch slave, throw-out bearing, pressure plate, etc.?

Mike

 

[Eleven]

Am using DOT 4. The slave was rebuilt maybe 5 years ago. The master never as long as I have owned it. The throw out bearing, clutch plate and pressure plate maybe 8-10 years ago but the car was down much of that any only has been really run seasonally the past 3 years. They have all worked fine and do not believe that is the issue (I hope!). The fluid level rise is odd. I think, Mike, that your thought might be something.

 

[Jay Laifman]

Are you 100% sure you've always used the same exact fluid?

When I got my Tiger, I presumed (bad mistake) that it had "normal" fluid in it - not realizing that it had been changed to synthetic. I decided I should bleed all the hydraulics. At the time, I didn't take note that it had a slight purple color - just assumed it was a brand thing. Everything worked great for a while. Then the clutch started acting odd, until complete failure. That's when I realized what had happened.

I can't say that it caused the fluid level to go up. But I do understand that switching can swell the rubber. I would assume the amount of swell really isn't enough to materially move your fluid level. All the same, I thought I'd mention it just in case.

As an aside, there was a German fluid brand that had blue and gold, with the idea that you would switch which color you used each time you bled, so you could make sure you replaced all the old fluid (when the color changed). But the US outlawed it.

 

[hartmandm]

Tracy,

Based on the background provided, it sounds like you can focus on the master or the slave.

How was the clutch slave rebuilt - was it sleeved or were just the rubber bits replaced?

If the clutch master is original and never rebuilt, I'd probably start with that. I had mine sleeved by White Post Restorations a couple of years ago. Not cheap, but I expect it will last a long time.

BTW - While you are messing with the clutch hydraulics, you can add a speed bleeder to the clutch slave to simplify the bleed procedure. I installed a
Speed Bleeder SB71620-SS. I found out the hard way that you have to use a vacuum pump initially to pull some of the air out of the line. With a lot of air in the clutch line, depressing the clutch pedal does not generate enough force to overcome the one-way valve in the speed bleeder. Once the vacuum pump is pulling some fluid through the valve, then you can switch to pumping the clutch pedal to bleed the rest of the air out.

Mike

 

[Jay Laifman]

I love speed bleeders. I have them on my brakes, not clutch.

A warning about vacuum pumps though. I hate them! I was using one once, had to put it down to check the MC fluid level. Because of the twist of the hose, it didn't balance well and tipped over. That initially wasn't a big deal. At least not that I thought. Then I went to pump up the pressure, and brake fluid sprayed out of the air valve all over my paint!!!! TOTAL PANIC to wash it off immediately.

I'm sure with more care to make sure the thing doesn't fall over, it would not have been a problem. And it actually didn't end up harming the paint. And maybe the situation that caused fluid to get into the air valve that caused the spray was a bizarre combination of events. But it happened, and I'll never use one again.

FWIW, I have since bought a Motive brake bleeder that puts pressure in through the MC. I love that one. So easy. Never run out of fluid. Great solid brakes.

Of course none of this goes to your issue.

 

[Jay Laifman]

Oh, another thing. There are two types of speed bleeders. One has a tiny check ball in the body of the bleeder. The other one has a tip that is on a spring. I like the second one better. It allows more fluid to go through because it's not restricted by the tiny check ball. I don't have the numbers for that one. I think I got them at JEGs.

 

[puff4]

I wonder if your pressure plate has sprung, and as such it’s now pushing the lever arm and slave back farther than normal? That would also explain the non-functional clutch.

 

[Eleven]

Boy, a lot of good thoughts and information! Thanks you. I had never heard of speed bleeders; they look like I need to install them. Anyway, my hope is that the pressure plate has not sprung, a last resort deal given the task to replace it. I also think that it is still okay because after giving the clutch pedal a good half dozen fast pumps, the car went into gear at idle easily.Was not doing that two days ago. My thought then is that it is hydraulic and either or both the Master and Slave need rebuilding. I did not have the Slave re-sleeved. The surface was smooth and clean. Since I have not taken the Master out yet, we shall see. If I do need to get things sleeved, where would I do that? Am suspecting that the rise is fluid level is either global warming or one way blow by from a plunger (probably Master) if that is possible. Thank you for the help!

 

[Eleven]

Oh, on the speed bleeders, what length and thread are needed?

 

[hartmandm]

Oh, on the speed bleeders, what length and thread are needed?

It is 7/16"x 20 tpi. "Regular" length works.

The one I used is stainless steel: https://store-speedbleeder-com.3dcartstores.com/SB71620-SS-9415-H9415-Speed-Bleeder_p_40.html

You can get steel versions for less money. Jegs lists some options.

Mike

 

[hartmandm]

Original bleeder on the bottom.



Mike

 

[RootesRooter]

Does the problem present itself as soon as you start it up, or does it get worse the longer you drive? I'm wondering if the hydraulic line could be routed up against the exhaust.

Also, I've had a relatively low-mileage (20,000?) clutch plate break a spring with similar results.

 

[Eleven]

Dick, that is a very good question! Recently it presented on start up but I have noticed in the past that the trans will get a little "notchy" when the weather and car get hot. Will check that out. Given that it worked well after a few quick pumps I still think it is hydraulic. Its been hot here and could be the heat issue in the pipe is causing some fluid deterioration or other stuff. Will check that out. And, Mike, thank for the info!

 

[Eleven]

Well, still not sure why so much fluid in the master but I sorted the shifting issue. Low oil in the transmission. Hope I didn't damage it. No sign on the garage floor or underneath the car but probably spinning out of the rear seal. Refilled in and will check at frequent intervals.
Have no interest in fixing this now. Thank you for all your help!