Hi all,

So I have a new Valair single disc clutch with all new components, and new OE hydros from Napa. I have about 1000 miles on the hydros and 550 on the clutch. Today I noticed that sometimes, as I'm slowly letting up on the clutch pedal, it feels like it is sticking or binding kind of. It is only minor and only when I let the pedal out very slowly, which I normally do, and even then its not all the time. Its like it will just kind of hang up slightly then let go and release more quickly than I want it to. I am sure the clutch and components are installed correctly as I and my dad did it together and we are both pretty competent in this area. We also had the help of a friend who is a lifelong mechanic.  I checked the FSM and didn't find too much except to grease the pedal pivot point. But in the case of binding, it says to replace the hydros. Since they are new maybe I could grease the pushrod? How would I do that? Just smear some synthetic grease on the pushrod and work it in and out? Has anyone else ever experienced this and or found a solution or have any other ideas?

Edited February 23, 20169 yr by leathermaneod

i experienced some of that with my Valair. Installed a SB on the same hydros and no issues. i dont think my problem was in the hydros. I think either my throw out bearing was binding or the clutch disc was binding on the input shaft.

Like myself I'm running NAPA hydro's and Southbend Con OFE clutch no issues. So I really doubt it all going to be hydro's. Typically a bad hydro will bleed off and start engaging when you hold the clutch for long periods. Typically you'll see fluid wetness on the firewall side or maybe weeping into the bellhousing. I heard of on case where a pin hole was in the tubing. 

Thanks for the input guys! That's very odd about your experience dripley. I'm really hoping if I remove the pedals, replace the bushings, and grease everything my problems will be gone. Otherwise I guess I'll be calling Fred at dap and valair to tell them about this. Did it last thought out the whole time you had your valair?

For the pedal pivot I would lay a big shop rag on the floor and hose the pivot with silicone spray and see what it does for the pivot.

I thought of that, but what if the Teflon bushings are worn out? The lubricant wouldn't help then would it? I do have some fairly minor side to side swing in the pedal so I'm really hoping its those bushings...

Edited February 24, 20169 yr by leathermaneod

Then your in for a big job of getting the pivot pin out so you can replace them.

Really? It doesn't look that bad...I saw a few people on Cummins forum that said it was easy and leads than an hour of work...am I missing something?

Maybe you got more room that I do... I've got big hands so a little bit of room goes away fast... 

Why not do us a favor and create an article of what you do on that pivot if you go that far...

Sure I can do that. I'll try to take some pics too. I did try to grease that pushrod btw. As soon as I did I realized that it does not rub anywhere. So then I tried just getting some grease on the inside of the master where the piston is to see if that would help. I went for a drive to get fuel after that and it didn't help. One interesting thing I did notice though was that it seemed worse with the heat on the floor. I don't normally have the heat all on the floor but I did some tonight and it seems a little worse.

Be careful with grease near any kind of brake fluid system. Grease and oil will destroy seals in the hydraulic systems. 

The Valair I had was very grabby from day one, but I did not get the feel that you described until later in its life, maybe 50k or 60k miles. The throw out bearing went not long after that. The binding sensation stayed with it until I replaced it. 

I am sitting here with a new slave cylinder and the instructions say to not let any petroleum based fluids come in contact with hydraulic clutch system or brake fluid. Gas, oil, transmission or power steering fluid, etc, Not sure why but maybe you ought not grease the master and slave rods.

Darn it that really sucks ;-( I'm probably ruining my new clutch hydros then. Should have asked you guys before I tried the grease. I didn't just put it on the pushrod, I put it in the back of the cylinder where the pushrod and piston are. I thought maybe it would help if it was binding somehow. It is synthetic grease bit I'm not sure if that will save it or not...do you think there is anything I can do about it or just wait for it to start leaking and then replace it? Mine has not been grabby at all...just as smooth as the old one, which was a lik btw. This slight binding just started after only about 550 miles on the clutch....

Edited February 24, 20169 yr by leathermaneod

  I take it the grease is just on the out side of the master.  Try spraying it with brake cleaner. Brake cleaner will not harm the rubber parts but don't get it into the fluid reservoir.  I think you may dodge the bullet.

It does say petroleum based so maybe there is no big deal with synthetic. Not sure why it would matter unless it bad on the seals.

Yeah I definitely didn't think it would hurt anything. I'll try the brake cleaner tomorrow. Yes it should be only on the outside...I only put it on the outside. Only way it could have got in is off the piston pulled it in or didn't clean it off the walls of the cylinder. Pushed the pedal in and stuck grease in behind the piston if that makes any sense. Do you think brake cleaner will get into the reservoir if I spray it behind the piston where the grease is?

Edited February 24, 20169 yr by leathermaneod

I too have heard that replacing the bushings on the pedals is fairly easy. But I remember how much fun it is to work under there with 3/4 of me hanging out of the cab. I have just started feeling a little sideways movement in the brake pedal when I depress the clutch. So I figure it is in my future.

2 minutes ago, leathermaneod said:

Do you think brake cleaner will get into the reservoir if I spray it behind the piston where the grease is?

No It shouldn't.

Years ago I work on a brake system that someone put ATF in the brake fluid reservoir.  The master leaked and the brake hoses had ballooned up.  Replaced everything but the hard brake lines. 

Thanks for the tips again guys! Is there anything else I should spray into the back of the master after I clean it out with brake cleaner? I know brake cleaner kinda dries stuff out, is there any other lubricant that would be safe for up in there? 

I ran into this very same "sticky" clutch pedal feel about 5000 miles after installing my SB clutch.  I did everything as I've always done on any clutch job, and was feeling like the problem was the hydraulics.  But.....the strange part was the clutch pedal movement was smooth when the engine was not running.  Strange.....

So after pulling the hydraulics and finding that they were fine, I reluctantly pulled the tranny back and found that the throwout bearing was hanging up on the input shaft sleeve.  Upon the clutches initial installation I lightly greased the input shaft sleeve, but I think what happened was that the clutch dust was incompatible with the grease I used and eventually turned that grease into sticky crud instead of lubricating.  Kind of the same thing as what happens with molly grease.

I cleaned the sleeve off and bought a new throwout bearing (just because I was in there).  This time I used no grease aside from what was pre-lubed in the new throwout bearing.  And after putting it all back together, the clutch pedal has never felt so smooth.....  It even feels lighter and the clutch engages better.  In point, it appears that the throwout bearings sticky movement on the shaft was causing more issues than just a jerky clutch pedal.

If you find that hydraulics arent the problem, you might be experiencing the same issue I was.

Edited February 24, 20169 yr by KATOOM

Ugh I sure hope that's not this issue. I appreciate the input though. I sure hope it's the pedal bushings! Mine does do it with the engine off though so who knows.