I was having issues with my clutch controller sticking and would frequently have to bleed the system during events. After fully disassembling my hydraulic system and sending the parts to be examined in the lab, we discovered that my master cylinder was the culprit. The piston in the master cylinder was wearing considerably and leaving debris throughout the entire system.
I was running Wilwood master cylinders previously. I have recently decided to switch to a Tilton master cylinder for the 2024 season. You can see my results and reasoning in the video below. Enjoy!
Video Transcript:*
All right, I want to talk a little bit about the clutch controller, I've had a couple of issues and wanted to share with you what I found, and what the cause was. So first thing I want to do is talk about the master cylinder, the clutch master cylinder, because the issue that I had just jumped right to it, the hydraulic cartridge, which is right here. This is the hydraulic portion with the manifold.
For the clutch controller, this is the cartridge that we're talking about right here. That is subject to contamination. And that's what I found was that I probably wasn't diligent enough with my cleanliness on the clutch, master cylinder fluid system, and I got a bunch of debris in it, I'm going to show you a picture here, I had three cartridges that I had that were doing some weird stuff. In fact, just street driving it with the controller unplugged the system, not even active. The clutch was sticking, like partway, and I'd have to crack the line and bleed it. And that was super frustrating.
But came to find out it was a hydraulic issue and not an electronic issue, which, you know, I didn't think it was but wanted to make sure. And let me show you kind of what I found over a couple of years, but even most recently here. So let me flip this around. So I run a willwood point seven five master cylinder for the clutch. And the setup that I run is a modern drive line. Linkage underneath, and I'll post a picture of that. But it makes it super nice, like the hydraulic pedal is super soft. It's like I drive a Volkswagen Golf stick shift. And it's as easy as that clutch. But this is a 2700 pound pressure plate. So it's kind of amazing that it works that easily.
But the one thing that it does is there's a little bit of an arc to the travel of the rod for the master cylinder, which is this here. So this is the rod that comes out of the back of the master cylinder and it has a little bit of an arc. So it causes it to deflect a little bit in certain spots of the travel. And what it does is it puts some wear on the piston in the master cylinder. And I'm going to show you that right now.
So this one keep in mind, this one had been in the car for a number of years. And can you see how it looks like that circle is off center? Well, it's not off center, it actually wore the body. If you can see that get this thing to focus, you're totally wore the body of that piston that's inside the master cylinder. And this is the one that came out of, I don't know if you're gonna be able to see it. Yeah, I don't know if that's gonna focus but trust me when I say the bore is worn, like this one is not that one is not rebuildable because it's worn. Now here is the one that went in. After that. They changed the design slightly. It honestly looks like they may have beefed up the casting a little bit.
The black is pretty but doesn't really matter to me. This is the piston that came out of that one. And you can see that it's also a little bit worn. where I'm going with all of this is the wearing of this piston, put debris into the system. Now I'm changing out everything and I'm going to try a different master cylinder. We're going to talk about that. But it was pumping debris from the master cylinder and potentially from the reservoir, which is here. This is the one I was running. And this is where I wasn't being very careful with how clean it was. If you look down inside there there's a bunch of trash in there. glittery stuff, just find debris.
And this is the master cylinder I was using. It's also Uh, I don't know if this is a Wilwood or what this is, but, you know, it was in the car for years. And it worked fine. But what ended up happening is the cartridges were getting full of debris. And there's some pretty fine orifices inside there. And it was causing it to jam up, not work correctly. And we just kind of realized this when I disassembled the third master cylinder that was in here. So let me show you this.
So the piston, this one isn't really too bad. But when I ordered, it looks like they've gone back and forth between piston designs. So I ordered a rebuild kit for it. And this is the piston that came with this one's brand new. Obviously, it's different than this design. I'm not sure which is better, because that's the old one, and it was worn pretty good, too. But what I see here is it's not quite you know, it's not super long it to me, if there's any angulation in the rod coming into it, well, it's going to be from this side, actually, it can cause this to tilt a little bit, which would definitely cause it to deform and wear God you can totally see the wear on that one. It's so bad compared to the other one.
So this is the master cylinder that's a just took out of the car. And this one probably shows very little where I put it in just before the last race week, and we didn't even finish because we broke the motor. But what I am, what I'm going to do is I'm going to swap over to this Tilton style master cylinder they built up the same the flanges are the same, but let me let me take that apart real quick and show you the difference on the inside.
Because I think that might be part of a tilt master sonar is about two to three times as expensive as these Wilwood ones, but that might be for a reason. So let me let me take this thing apart and show you exactly what I'm talking about situate this thing so we can catch this grab a tool.
Okay, so look at the difference in the piston design. The Tilton this one is as two seals. Now, this one's probably just to manage fluid. Because there are some, there are some holes down here looks like when this is in there, fluids only going to be able to flow in one direction because the seal is going to prevent it from going back the other. But what I see in this design that I like better is if there is some angulation this has, it's much longer. It's actually not a ton longer, but it is a little bit longer.
And after speaking with Tilton on the phone, the inside of this is hard anodized I don't know about the willwood I didn't speak to them, but I think this might be steel. Let me grab a let's grab a magnet here and see if one is steel and one is not. Alright, let's take a look at that one steel. That one's aluminum. So this is not going to wear like an aluminum one because that's much softer. And if this is hard anodized then it should wear much better. Hence, probably the more expensive price.
And we're just gonna see it's the same exact bore diameter. So point seven, five or three quarters in my case, and that won't change anything as far as the pedal ratio. And then I'm also putting a new master cylinder in let me show you the one I'm putting in it is a modern drive line one, where's the cap? Let me find the cap here. Here it is, all right it's a bit of a tight fit in there, we're probably going to shim it out a little bit.
man goes, Okay, so this is a, it's cast aluminum, there's not any ribs or anything inside it, I'll pop the top again and show you and it has a dash for male fitting on the end. So what that means is, yes, I'm going to put a braided line on the feed for it. And not a rubber line. Now the rubber line was rated for brake fluid. But if you can see inside there, it's smooth. So would be very easy to keep clean as well. And you can see on the display here, it's also got that type of master cylinder on it. So again, it's smooth down inside there. And it's going to work pretty well. Let me and then I've also totally flushed out the lines.
So this is the manifold assembly, the lines, I've completely flushed them out. And this is the line that goes down to the clutch pedal. It's a lot like this one on the display here, I have a quick release on this. That goes down, it just makes it way easier. When I have to pull the transmission, I don't have to reboot bleed the line. If I'm at race week, that's a it's a dry disconnect.
So it doesn't let any air in the line it doesn't drip any fluid, I can click disconnected, I can pull the transmission and put it back in and not have to re bleed the clots, which is huge. And this is what that connector looks like. At least that's one side of it there. And then the other side is over here on the transmission, I'll show that to you. So this is the other side of it here. And it's just a yeah, it's just like a quarter turn deal snaps in there works pretty well keeps it keeps it dry.
As far as no fluid leaking out, no air getting in. So another little piece of information that I think is worth mentioning, is the line that goes from the master cylinder to be this your pressure out on the master cylinder on a new one, it's going to be this one, the line that goes from there into the manifold, which is going to have the hydraulic cartridge unit, which will look like this when it's all assembled. Okay.
And then the line going down to the transmission. In my opinion, this line should be as long as possible because if the master cylinder is generating debris, which in my case, it has been, then that line is much longer meaning it will take longer for it to get there, which gives you more time between service intervals of flushing it all out, which I think for me is going to be annually so before each season of racing, I'm going to disassemble all this completely flush the lines out.
There is a filter that we designed and put in the cartridge. Here, this stainless steel one here. Let me see if I have another one to show you. That's not installed. Okay, do there's one in this bag. There's one that's flat too, but that one's good. So that's the, that's the filter. This is what it looks like.
And it is pre installed that that goes on there to help keep some of that debris and material out of the cartridge. But it's super important that you keep that thing clean. Because if it's dirty, it's not going to work right? And you're not going to be happy you go to launch the car and it's not going to slip or it's going to slip too much or it's going to stick and that was the problem I was having to be honest with you.
And I'm just gonna Tell you the truth. It was a cleanliness thing. It's just that's just being dirty and it wasn't working right so that's my two cents. That's what I have for the clutch controller tech tip for the day or the season. You got to keep this thing clean. So little work. That's it. Let me know if you have any questions.
*This transcript was automatically generated from the video and may contain errors.