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Clutch Line PTL / CDV - DV6Z-7A512-A vs -B ('Bang' TSB revised part)

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45K views 72 replies 29 participants last post by  GNocide  
#1 · (Edited)
Hello all! Proud new owner of a 2k13 Peformance (Spirit) Blue ST2 reporting in!

After reading over the 13-6-10 RMM TSB, and the TSB mega thread, I'm still curious about the Clutch Line PTL (Peak Torque Limiter). Here's an excerpt of its operation from this blog

Peak torque limiters are moveable orifices within the hydraulic line which reduce the volume flow during clutch engagement. They protect the drive train from overload caused by a sudden clutch engagement, e.g. if the driver’s foot slips off the clutch pedal. During maintenance, peak torque limiters must never be removed from the hydraulic system, as this can damage the transmission, the drive shafts or the Dual-Mass Flywheel.
Since the first day I drove the car, I noticed that the pedal wouldn't fully engage if I'd lift VERY fast (boarder-line side-stepping). The engine would bang around, and I'd actually feel the pedal smack up against my foot after a short delay. I figured it was this valve preventing the flow of the hydraulic fluid, causing the dual mass flywheel and clutch to cycle between loading and unloading. The new TSB seems to resolve TWO issues: the weak motor mounts, and possibly an overly aggressive delay valve. I was wondering if anyone knows for a fact that the revised Clutch Line PTL (part number ending in 'B') lets MORE or LESS fluid through before it limits fluid flow.

I'm aware that the Honda S2000 scene has a similar issue, they call it a Clutch Delay Valve (CDV). It's great for daily driving, but not for spirited or track driving. Some S2k drivers go so far as to remove its functionality. I wonder how our cars would react to removing the PTL/CDV altogether (ignoring that warning in the description). It's a trade-off like everything else though...you'd be shocking the drivetrain more, but would have a MUCH more direct feel of the clutch.
 
#3 ·
Well i can tell you after getting the TSB done and swapping my flywheel and PP and clutch out the pedal still does this and I would rather it not. Someone(not me) is going to have to try and bypass the system or try an aftermarket alternative
 
#4 ·
Exactly why I went ahead and started replacing motor mounts on my own.

I have the transmission mount on order (well, back order) and I'll see if it will work with the stock clutch line. I never did receive a definitive yes or no on the stock clutch line fitting properly with the new transmission mount. If it does, Ill be happy, and will swap the mount. If it doesn't, I will stick with the stock trans mount and clutch line.
 
#5 ·
The clutch line PTL tube could have been revised for one of 2 things (or both):
a change in the actual flow rate it regulates, or​
the actual tube may be longer/comprised of a different material to compensate for new mount & the movement of the motor.​

Does anyone have access to both revisions of the Clutch PTL tube to do a visual comparison?

Maybe the aftermarket will develop a stainless steel PTFE line with the proper connectors at each end that replaces this clutch tube/PTL assembly... DO IT. :big smile:
 
#9 ·
#13 ·
Thanks for the picture, it's very informative!

It confirms that it also replaces the PTL (Black piece that the tube terminates to).
 
#16 · (Edited)
Just picked my car up from the dealer installed TSB.

When I first got into the car, I immediately noticed that the clutch was not bleed properly. I asked them to pressure bleed it again, and a half hour later it was back to normal, and the clutch felt right.

After driving it, it became quickly apparent that the new delay valve is MUCH more aggressive. It so aggressive, in fact, that it feels like the clutch pedal sticks under quick shifts. If you SLOWLY release the clutch, it has no effect. The PDV only operates when you quickly release the clutch. When at a stop light, and putting the car in neutral, I normally quickly release the clutch. I can feel the PDV catch the pedal and slowly release the clutch. Like I said, the best way to describe it is a sticking pedal, and it's very annoying. The new PDV activates at a lower pressure I think (lower rate of releasing the clutch).

I don't like it at all. The bang is mostly gone, but I believe it's because the PDV prevents fast shifts.

You can see the effect of the valve, too. Kneeling next to the car, I pressed the clutch with my hand, and 'side stepped' the clutch. You can see the clutch pop back about 25% of the way, then decelerate the rest of the way to the top. It isn't slow, but noticeably slower than before. It sort of looks like a spongy/sticky clutch.

If you can avoid getting the new clutch line, avoid it!

I'm going to look into getting a clutch line fabricated that removes the valve altogether.
 
#17 ·
Just picked my car up from the dealer installed TSB.

When I first got into the car, I immediately noticed that the clutch was not bleed properly. I asked them to pressure bleed it again, and a half hour later it was back to normal, and the clutch felt right.

After driving it, it became quickly apparent that the new delay valve is MUCH more aggressive. It so aggressive, in fact, that it feels like the clutch pedal sticks under quick shifts. If you SLOWLY release the clutch, it has no effect. The PDV only operates when you quickly release the clutch. When at a stop light, and putting the car in neutral, I normally quickly release the clutch. I can feel the PDV catch the pedal and slowly release the clutch. Like I said, the best way to describe it is a sticking pedal, and it's very annoying. The new PDV activates at a lower pressure I think (lower rate of releasing the clutch).

I don't like it at all. The bang is mostly gone, but I believe it's because the PDV prevents fast shifts.

You can see the effect of the valve, too. Kneeling next to the car, I pressed the clutch with my had, and 'side stepped' the clutch. You can see the clutch pop back about 25% of the way, then decelerate the rest of the way to the top. It isn't slow, but noticeably slower than before. It sort of looks like a spongy/sticky clutch.

If you can avoid getting the new clutch line, avoid it!

I'm going to look into getting a clutch line fabricated that removes the valve altogether.
Wow. SCREW THAT. Thanks for the post. Definitely not replacing mine.
 
#18 ·
BMW did this on the E46 3 series.
Under aggressive shifting, the clutch would not engage quick enough, essentially slipping the clutch slightly.
Over time this would burn up clutch disc and scortch flywheels.

I had an aftermarket clutch / flywheel installed, confirmed the scortched flywheel.
I then had the clutch release valve removed.

The difference was night and day.
 
#19 ·
Also, sux that Ford chose to "fix" the 1-2 by adding a more aggressive PDV.
It's just yet another nanny.
 
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#20 ·
Haha, screwed!

We ran into this in the Camaro scene back in the early 2000s. Someone came up with a 'Drill Mod' where you take off the braided line and drill out the restrictor. It worked great.
 
#21 ·
Yea, I'm thinking the aftermarket needs to come in for the rescue. A direct replacement for the line and delay valve assembly, with a hard line or braided stainless steel.

I'm going to try to source another line and see if I can drill it out.
 
#22 · (Edited)
I just bought another one (the revised tube with delay valve). I'll try to take some detailed pictures and see if you can drill out the valve or machine a new fitting that replaces the valve.
 
#23 ·
I was driving around some twisties last night and I must say that the clutch line didn't bug me in the slightest. Quick heel-and-toe double-clutch downshifts are no problem - I no longer notice the new PTL as I did when it first went in. It's seriously not that bad.

There's a lot of moaning and *****ing about it, and it's scaring a lot of people away from the TSB because of it. I was worried about it, needlessly as it turns out.

Give it a few days, it gets better.
 
#26 ·
I don't know, maybe the tech didn't bleed it right. I find that the engagement point is the same, and the linear progression of the engagement is the same under stop and go conditions. However, under spirited driving, I feel like it gets in the way. Rev matching isn't as smooth as before.
 
#27 · (Edited)
For those of you who wish to modify your clutch line I have attached a few photos of what you need to do. The restriction for normal driving is not an issue for most, but for me its far from what I'm use to. I tend to drive conservative most of the time, but when I'm push it, I'm very aggressive. I feel that with the current clutch line my clutch will need to be replace more often then I would want. With more power, this restrictor will cause the clutch to slip when shifting aggressively, its already happened to me twice.

As you can see in photos, its a simple process to remove the restrictors. There is one on each end of the line. The one end has a clip and it pulls apart, the restrictor is easily removed. The other end has to be drilled out. You will know its drilled completely when the spring and very small restictor comes is out. The ends look like Mustangs, and there are braided lines on the market for Mustangs, but I am not sure there are exactly the same. Maybe one of the vendors here can work on getting a line made up. Once the restrictors are removed, there still a little restriction due to the inside diameter of the line, but for hydraulic fluid it should be fine. When testing with restrictors in place it was evident the restriction was more than it needed to be.

I have not yet installed the new line, I hope to have it in by the weekend and will give a report.
 

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#29 ·
Just what I thought would happen eventually. Instead of fixing it, they upped the nannies. The performance crowd doesn't care for that and will remove it.
 
#28 ·
Good luck with that , it might not work due to the fluid now having to fill up more "empty space " that was occupied by the restrictor , but do it and lets see what happens , I was going to do mine when I replaced my line but the restrictors don't bother me , anyway that line is cheap enough to be experimenting with
 
#30 ·
I have a feeling that won't matter very much. Subscribed to see results of how clutch feels after mod.
 
#33 ·
I had mine done last week and i am in the group of people that actually like it, it took a little getting used to at first but now i can speed shift the hell out of the thing and row through those gears like a madman and it adds a nice level of smoothness no matter how fast you rip your foot off that clutch pedal, that part along with the mounts and the power feels soo much smoother and now there is no wheel hopping even if i do fun burnouts in 1st gear ( which sounded like the a transformer having an orgasm before i had the tsb done to it) and something i didnt think would be affected by the t.s.b was how different the shifts feel now, they fell a little bit more mechanical and less rubbery. All i can say is that the t.s.b definately makes it a more fun car to drive
 
#35 ·
@Yo Ken

YES! That's exactly what I was hoping we could do. Why is the connection at the slave a "T"? Is that were you bleed the system from?

Speaking of which, how are you going to bleed the system?
 
#36 ·
Yes, that's were you bleed the clutch. There is a 7/16's nut to bleed the system on the end. I use a power bleeder from Motive Products, and it makes it a one man job. They are not expensive, it's a good tool to have in the garage. I will takes some pics when I install the line tomorrow and post a report on how it all turned out.