I have driven my Fiero for 3 days with no issues at all, yesterday the clutch engaged a little low once or twice, today about 1/5 of the time I press my clutch it acts like air in the line, goes down (a few inches, half way, or fully, at random) with no effort and doesn't disengage the clutch, I've had this happen about 15 times today, clutch fluid is full, with no leaks at all. Rodney master, slave, and clutch release arm (on transmission), and the clutch pedal return spring removed (when changing bushings). Fiero ran fine all last year without issue, and the first 3 days out of hibernation, but now seems like it has air in the system, can air be intermittent like this, one press full pedal, next to the floor? When it goes to the floor, it will "pump up" in that if I press it again one or twice it will firm up. I will bleed the system in 5 hours when I get home, but I want to know if that is the issue before embarking on that.
Ok, I discovered the issue, it was in fact my Rodney Dickman early master cylinder. The valve between the reservoir and the cylinder failed, allowing fluid pumped by the piston to flow back to the reservoir instead of to the slave cylinder.
My thought is that it might have something to do with the non OEM travel of the master cylinder, with the piston bottoming out every shift, instead of the pedal stopping on the floor, might have damaged the valve in some way. My thread addressing this problem when I first got the master cylinder: https://www.fiero.nl/forum/Forum2/HTML/147068.html
For every other product, quality and support has been exceptional, but with this one, the best Rodney did was offer to have it shipped back to see what was different with it (while confirming that his stock measured the same as my example, which measured short of my OEM cylinder, and other replacements)
I will likely end up with another Rodney master, whether a "warranty" replacement, or if I must buy another, I love the feel, but am now very concerned about the longevity of future replacements if my problem is connected to the short travel.
Nothing against Rodney, but I feel something in this product was either designed wrong or messed up in production, which wasn't noticed until it was "too late"
Ok, I discovered the issue, it was in fact my Rodney Dickman early master cylinder. The valve between the reservoir and the cylinder failed, allowing fluid pumped by the piston to flow back to the reservoir instead of to the slave cylinder.
Nothing against Rodney, but I feel something in this product was either designed wrong or messed up in production, which wasn't noticed until it was "too late"
I don't know when you bought that Dickman clutch master, but he did have a problem a few years ago with them. It might've been limited to a bad batch, I don't recall the finer details.
Dickman clutch slaves with their dual-seal pistons are fantastic, and I wouldn't wish to own a manual transmission Fiero that doesn't have one of these installed. Having said that, the clutch master is far less critical. I replaced the clutch master cylinder in my Formula a couple of years ago with the cheapest one I could find at RockAuto. It's been absolutely fine ever since.
[This message has been edited by Patrick (edited 04-18-2024).]
I don't know when you bought that Dickman clutch master, but he did have a problem a few years ago with them. It might've been limited to a bad batch, I don't recall the finer details.
Dickman clutch slaves with their dual-seal pistons are fantastic, and I wouldn't wish to own a manual transmission Fiero that doesn't have one of these installed. Having said that, the clutch master is far less critical. I replaced the clutch master cylinder in my Formula a couple of years ago with the cheapest one I could find at RockAuto. It's been absolutely fine ever since.
I got mine last July, he was running on overstock then and still is, it seems, as the manufacturer quit or something. Yeah I just put the rock auto one back in, but I love the feel of the Rodney one much more, oh well, I'll see what Rodney says about it.
I don't really understand what you're saying here. A clutch master cylinder either works properly or it doesn't. Where does "the feel" come in?
My old Rodney one failed, it feels horrible now because it's broken, but when it worked it "felt"much better then the rock auto one, smoother, more precise, etc. so I will likely end up getting another one, whether a "warranty"replacement due to the early failure, or I might have to buy another one, as I much prefer the feel of the working Rodney one then the working rock auto one
I still don't understand how a properly functioning clutch master cylinder could feel much different than any other properly functioning one. The length of the banjo could effect how the overall operation of the clutch "feels", but IMO that's much more dependent on the banjo itself rather than of the master cylinder.
I still don't understand how a properly functioning clutch master cylinder could feel much different than any other properly functioning one. The length of the banjo could effect how the overall operation of the clutch "feels", but IMO that's much more dependent on the banjo itself rather than of the master cylinder.
Even off the car, empty of fluid, the rock auto one is stiffer, more jerky, Rodney one is smoother, either the bore is more polished or the piston is a better fit, also I do think the rock auto one is a slightly smaller bore then the Rodney and OEM (speculation), only slightly, as pedal pressure is slightly less (which I personally don't like).
This LuK unit is what I bought three years ago. It was about $22(US) at the time. Operation is smooth as glass. "Feels" good to me.
Interesting, is that cast iron? Usually the aluminum ones aren't black. If so that might have an impact on it, I got the perfection clutch one, externally looks very very close to Rodney's, but lower quality, more burrs, different reservoir, etc.
Might be... I don't recall, and I haven't had to look at it for three years. I'll take a peek at it when I'm out by the car again.
Your master is also of the earlier design. That may or may not make a difference in how it operates/feels.
Yeah I know, that's what this whole thread is about, my dad has the later design from rodney, with no problems, with OEM travel and good "feel" mine is the early version which didn't seem to have full travel, but same good "feel" and quality.
It unfortunately failed prematurely, which may or may not be connected to the shorter travel. Rodney says he'll try to find an early OEM to compare his to. I know there's nothing he can really do, but if anyone buys that line off him, or he gets it going again, it would be good to make sure that any issues are solved, or at least noted.
Once again, I love Rodney's products, in the last year, I have spent... A lot on his site, that $80 master cylinder only added up to 5% of my total purchases, he made a few minor mistakes, but never hesitated to right them immediately, with the only other quality issue being on the shifter boot (might have been damaged in shipping, might have been a poor weld/fluke) which he promptly sent a second one, free of charge.
First design 84 and if I recall 85 are an aluminum body with the fluid port to the rear of the reservoir. 2nd Design was a steel body with the fluid port forward of the reservoir. They can be interchanged, I've always used the 2nd design even on the early cars, you just have to rework the steel clutch line.
Rodney confirms that his early slaves have a 4mm shorter travel then OEM, and is surprised noone caught this sooner, the connection between that and my failure is still speculative, and I am still in conversation with Rodney regarding this.
Yes. I would assume that, I just copied what he wrote without thinking I guess.
"I did find an OEM GM master and my slaves do indeed have a sorter travel. 4 mm less. I never checked one to compare. But why has everyone else not had this problem?"
I'll take a peek at it when I'm out by the car again. 
