[Nai150]

I just replaced my clutch (ClutchMasters Fx250) flywheel (Ark) as well as the slave cylinder (and removed the spring) and installed a steel braided clutch line, the car shifts decently ish and everything works, but the pedal feels incredibly soft and my transmission now grinds hard going into reverse, i've tried bleeding 3 separate times, any advice is very appreciated!

 

[Nai150]

 

[Nai150]

replaced my master cylinder, now the pedal feels firmer and like a real clutch, but the car still has a hard time going into gear from a stop and it grinds going into reverse (unless you put in a gear and then immediately go into reverse for some reason??) I tried adjusting the pedal as in the pictures below, I adjusted it into all different places on the rod and it wouldn't go into gear at all! I called it quits for the night and when I came back to it the next day it was back to going into gear! (I have the adjustment for the longest possible) still grinding and tough to get it but it goes into gear again, so I am really unsure of what to do now, I have found that the master cylinder I bought from oreillys, the rod is almost a half inch shorter than the OEM one, is that the problem? do I need to buy the OEM master cylinder for that extra half inch on the rod? the pictures above of my slave cylinder, the 1st is at rest, and the other 3 are with the pedal touching the floorboard, that doesn't seem like a lot of movement? is that how much it normally is?

 

[Nai150]

I had mega issues with the aftermarket master cylinders. The rod is actually shorter. I purchased an OE cylinder, used castrol srf fluid, and purchased this Clutch Pedal Adjuster

Have not had an issue since.

what were the issues you were having? how did this aftermarket adjuster help? Thanks

 

[Nai150]

I bet your master cylinder throw is not adjusted correctly. Judging by the set nut being in the wrong location. If the throw isn't set properly the valve in the master doesn't allow flow back to the master decreasing the distance that the clutch will disengage the next time you apply your clutch pedal.

View attachment 137376

Grab a friend and follow the master cylinder setup process outlined by these guys just following the bleeding process in this video:

thanks ill give it a shot, the nut you circled in the picture is the locking nut to keep it tight, not the adjustment nut, although in that picture it adjusted to be as far out as possible

 

[Nai150]

Just remember that the rod's throw adjustment isn't like it is on a cable clutch adjustment that can give you an adjustable grab point. The rod's throw adjustment is for the valving inside the master to allow flow in either direction. If it's incorrectly set you will effectively have a one way valve with a rock hard pedal or a soft pedal. Anything in between may work intermittently.

Since it is set to be as long as possible, the valve isn't closing to pump pressure until about 25% or 33% of the clutch pedal distance. That means you have that much less distance to build pressure and fully disengage the clutch. Adjust it with a friend like in the video and you'll get back all the pressure and distance you need to get in and out of gear without any issues.

thank you so much, I've been practically ripping my hair out trying to get it back on the road for the past 3 weeks, (i had a bad axle seal and oreillys gave me the wrong part twice before they realized they don't carry the correct seal so i had to order it from the dealer, and then I've had nothing but issues with this since then) I will most definitely give it a shot! thank you again!

 

[Nai150]

Just remember that the rod's throw adjustment isn't like it is on a cable clutch adjustment that can give you an adjustable grab point. The rod's throw adjustment is for the valving inside the master to allow flow in either direction. If it's incorrectly set you will effectively have a one way valve with a rock hard pedal or a soft pedal. Anything in between may work intermittently.

Since it is set to be as long as possible, the valve isn't closing to pump pressure until about 25% or 33% of the clutch pedal distance. That means you have that much less distance to build pressure and fully disengage the clutch. Adjust it with a friend like in the video and you'll get back all the pressure and distance you need to get in and out of gear without any issues.

Well I gave it a shot, I can't find the point where the valve closes and I can't push the slave back, so I instead tried every position on the rod... None of them work, not sure why I can't find the point where the slave doesn't push back, any ideas?

 

[Nai150]

Could be a faulty or incorrect master cylinder if you're unable to push back on the slave. The valving or rod may not be correct. Do you happen to have a photo of both the new and old master cylinders?

I replaced my master cylinder which was slightly different than the OEM for my V6/6Speed from a cheap "OE" manufacturer. I tried it regardless thinking it was a different design revision or part update but I could never get it to work right. I decided it was likely from a V6/5Speed or L4/5Speed and tossed it out. Never figured out why it was different though. I ended up sourcing a used OEM master cylinder and it solved my problems.

sorry I should've worded better, i cannot find the point where I can't push the slave cylinder back, I'm always able to push back on the slave, sure I'll get some photos of the oem one and the new oem i just bought

 

[Nai150]

Try shortening the rod adjustment as far as you can to see if it stops letting you push it back in. Infact is there ever a point while slowly pressing down on the clutch where it stops? That's a good indicator of how far you need to shorten the rod. If there is no point which it stops then you may have a faulty or incorrect master cylinder.

ill try that, do you mean by "where it stops" as in when im pushing down the pedal the slave cylinder stops extending yet i have more room to push farther?

also thank you again so much, you're a massive massive help

 

[Nai150]

There should be a point while pressing down on the clutch pedal where you won't be able to push back on the slave cylinder because the valving inside the master cylinder is only allowing flow in one direction. On a normally functioning car that should be within about 0.25" from the top of the pedal location. If you have to push on the clutch a fair amount before it blocks reverse flow from the slave cylinder this is a good indicator it's the wrong master or could be damaged. Could also be an indicator it was never bled properly.

Wait your saying when I'm pushing the slave back to see if the valve is closed I should have someone press on the clutch pedal during that time? That's not what I understood from the video and would make sense as to why I can't find that point

 

[Nai150]

I made a mistake with this advice. I meant that you should adjust the rod longer until the slave stops pushing in. Then you shorten it one to two turns so that you can push back on the slave to return fluid back to the master reservoir.

Essentially you have a variable one way valve in the master cylinder. You want to adjust that master cylinder rod so that the valving allows flow back to the master reservoir with the pedal all the way up in it's resting position. You may have to lift the pedal by hand or foot to it's resting position if the clutch isn't resetting it's position for you. You want the valving the block that flow with about 0.125-0.25" of pedal travel so that pressure builds to disengage the clutch when fully pressed to the floor. If the master rod adjusted too long, the valving will block flow back to the master reservoir at the pedals resting position preventing clutch engagement when the pedal is released. Then if it's adjusted too short it may build pressure too late in the pedal travel to be effective enough to disengage the clutch. There is a fine line of adjustment where it needs to be to function properly.



You don't want to press on the clutch pedal while you are doing the procedure from the video for the final adjustment. What I proposed is as a simple test to see if you have a point at all in the pedal travel where the master valving prevents you from pushing the slave rod in. IE if the master rod is adjusted to the shortest or longest and you can still push the slave rod in... then have someone softly press on the clutch pedal until the valving in the master prevents you from pushing on the slave rod in. If the distance you have to push the pedal is significant like 50% pedal travel, there is no amount of adjusting the master rod that will fix this and you should look into obtaining another master as a last resort.

ok great I'm understanding this better now, my point earlier was that even when I have the master cylinder rod adjusted as far out as possible, I can still push in on the slave, I can't find the point where that valve closes

 

[Nai150]

I made a mistake with this advice. I meant that you should adjust the rod longer until the slave stops pushing in. Then you shorten it one to two turns so that you can push back on the slave to return fluid back to the master reservoir.

Essentially you have a variable one way valve in the master cylinder. You want to adjust that master cylinder rod so that the valving allows flow back to the master reservoir with the pedal all the way up in it's resting position. You may have to lift the pedal by hand or foot to it's resting position if the clutch isn't resetting it's position for you. You want the valving the block that flow with about 0.125-0.25" of pedal travel so that pressure builds to disengage the clutch when fully pressed to the floor. If the master rod adjusted too long, the valving will block flow back to the master reservoir at the pedals resting position preventing clutch engagement when the pedal is released. Then if it's adjusted too short it may build pressure too late in the pedal travel to be effective enough to disengage the clutch. There is a fine line of adjustment where it needs to be to function properly.



You don't want to press on the clutch pedal while you are doing the procedure from the video for the final adjustment. What I proposed is as a simple test to see if you have a point at all in the pedal travel where the master valving prevents you from pushing the slave rod in. IE if the master rod is adjusted to the shortest or longest and you can still push the slave rod in... then have someone softly press on the clutch pedal until the valving in the master prevents you from pushing on the slave rod in. If the distance you have to push the pedal is significant like 50% pedal travel, there is no amount of adjusting the master rod that will fix this and you should look into obtaining another master as a last resort.

when the rod is longest and the valve is closed like you talked about, is that because of that little sensor that the pedal rests on? when i take the master off of the pedal the valve is open, so i assume that closed valve is because you are supposed to adjust where the pedal rests until it pushes the pedal enough to where the valve closes, and then turn the rod side once or twice to open the valve again? well I tried that and I still am having the same problem, if i've done it all correctly the only thing that I can think is I have a TOB issue or a bent clutch fork (which I don't think its either one of those I think its an adjustment issue)

 

[Nai150]

The switch is simply to tell your ECM or BCM that you are depressing the clutch. One purpose is to turn off cruise control immediately if the clutch is pressed instead of waiting until the bottom of the clutch travel like it does for starting the car. But that switch does nothing to the master cylinder.

Once you have found a point which the valve blocks flow, shorten the rod by about 1-2 turns and that should set you just right. If you still have problems then you may have a faulty slave, faulty fork or faulty release bearing.

Another problem may be the clutch disc. Are you certain you installed it the right direction? Was it a sprung or rigid disc? The disc may need to be worn in a little bit more so it doesn't catch while fully "disengaged"

I'm in the process of pulling the trans off now, I'm positive I have it adjusted properly, it's on the right way, sprung, I put the same clutch in a buddy's car and he never had issues with it not going into gear during break in so I'm just gonna check everything and then probably replace the fork and try it again

 

[Nai150]

While you are in there, measure the depth of your ark flywheel friction surface to the flat area the clutch cover (pressure plate) mounts to. I'm curious if it differs from my Fidanza flywheel which is a common pairing with Clutchmasters discs.

Like this? Also I don't see anything visibly wrong in here at all

 

[Nai150]

The 2nd pic is the correct depth but the reading on your caliper is nearly 3inches or 70mm which can't be right.

I measured my Fidanza depth and it was 8mm or 0.32". My thoughts were if you depth was smaller than that, it's possible that the CM disc may need to be worn or flywheels.needs to be bedded in more to function normally.

What about the torque used on the clutch cover/pressure plate bolts? If you over torqued them you could have trouble fully disengaging the clutch.

i'll remeasure the 2nd pic, if I remember right i torqued them 4 lbs over spec because it was something like 14 foot pounds which i thought was dangerously little

 

[Nai150]

The 2nd pic is the correct depth but the reading on your caliper is nearly 3inches or 70mm which can't be right.

I measured my Fidanza depth and it was 8mm or 0.32". My thoughts were if you depth was smaller than that, it's possible that the CM disc may need to be worn or flywheels.needs to be bedded in more to function normally.

What about the torque used on the clutch cover/pressure plate bolts? If you over torqued them you could have trouble fully disengaging the clutch.

also I thought about that but I have almost 200 of the 600 break-in miles done so I figured it would be past that point by now, and I did a CM fx250 and fidanza flywheel on an Acura RSX and it never had any issue like this at all, always smooth easy shifting

 

[Nai150]

14 lbs is right for the bolt size and thread type. It's not about the work the bolt is doing, it's about the strength at which the bolt, threads or material you thread it into will yield and start to break. You size the bolt and threads based on the material and holding force you require. You don't need to go higher 14lbs and it will hold no problem since it has lock washers. My last clutch I torqued to 14lbs and it lasted 60k miles no problem.


It took me over 1500 miles to break in my last clutch because I drove mostly highway miles on a 1000 mile round trip as soon as the new clutch was installed. (Literally less than 12 hours after the clutch was completed) It really depends on the type of driving you do. They recommend stop n go traffic for the break in period for quicker results. You can subtract any long highway miles you drive since you aren't actively engaging/disengaging the clutch enough to bed in the materials.

fair enough most of the driving was highway but I was trying to do as much stop and go as possible, ill remeasure the distance for the flywheel and pressure plate, if it seems very abnormally off then I will buy a fidanza flywheel to replace the Ark, if its fine then ill just re-torque the bolts, replace the clutch fork and TOB, check over everything one more time and then put it all back together

 

[Nai150]

 

[Nai150]

I'm sure the ARK is fine. I was just curious what the depth would be from the flat mount point on the highest point of the flywheel. It's always possible that quality control was not so great the day they machined your flywheel. Although that's very rare for something like that to slip past QC on a precision part like that.

Looks like you have plenty of clearance that it shouldn't be binding on the disc while the clutch pedal is to the floor. I would continue troubleshooting the hydraulics if I were you.

ok cool, waiting on the clutch fork and TOB to show up then I'll put it all back together

 

[Nai150]

everything is back together, same issue... I took several measurements (as in the youtube videos) and the most interesting one is the bite point video (sorry you have to look at my feet I was past the point of care last night lol) there seems to be a decent amount of room before the clutch starts to bite, so I don't think its a problem with the hydraulics not extending all the way anymore, my first thought was fluid, I'm running Redline MT85 GL-4 (fresh fluid but i've been running the same stuff for over a year with no issues) but I wouldn't think if it was the fluid that reverse would grind, it would just be the synchro's that aren't happy.... no idea at this point, the car is still driveable, its just not smooth and to get into reverse without grinding I have to put it into 1st and then immediately take it out and get it in reverse, if I do that it doesn't grind