Changing fluids and clutch system gripe.

[Nine Ball]

Today I set out to change all of my fluids on my 2013 Viper, as I'm over 7000 miles now and the car has seem some track and drag strip use. Previously, I'd only changed the engine oil on this car.

Trans fluid and rear differential fluid require removal of the belly pan to access the drain and fill plugs on each. Pretty straightforward process. I went with Mobil1 synthetic ATF for the trans (4 quarts) and Mobil1 synthetic gear oil 75-140 (2 quarts) for the rear. The gear oil already has the friction modifier mixed in.

Then came the clutch fluid. These Tremec transmissions are notorious for having the clutch fluid become contaminated with clutch dust through the slave cylinder seal, and it is a good practice to keep the clutch fluid (which is just DOT4 brake fluid) clean and changed after hard driving.

Not so easy. On previous gens, the clutch fluid had its own reservoir under the hood, which made it easy to monitor the cleanliness and fill level. If the fluid was brownish or dirty looking, it needed to be flushed and changed.

The Gen 5 is not set up well for this routine maintenance. The feed line for the clutch fluid is now fed directly off of the brake master cylinder reservoir, essentially sharing the same brake fluid used for the brakes. To make matters worse, there is no longer a bleeder valve on the slave cylinder. It appears the feed line going into the transmission is the only line in. The bellhousing still has the hole where the bleeder valve used to be on previous gens, but the valve is nowhere to be seen. I'm not sure why SRT decided to combine the two systems into one, and get rid of the bleeder. Not sure how else I can ensure that fresh fluid is inside the slave cylinder, after I change the fluid out.

Kinda frustrating. I may plug off the feed nipple from the brake master cylinder and add my own clutch fluid reservoir under the hood. That would make it easier to monitor the fluid quality and level. But, this doesn't solve the missing bleeder issue.

Tony

[Allan]

There are some other cars out there that use the brake master cylinder as a common reservoir for the clutch system, so it's not a new idea.
I totally agree that it sucks, as I prefer to have that stuff separate.

Of all the things to 'improve or change' from the previous Vipers, I don't see why they went to that set up.
It cant be much cheaper, doesn't make the car faster, lighter, more exotic, better reliability, or anything.

Things that make you go -hmm.............


......they must have had some reason to do that.

[J TNT]

New Mustangs have the same set up , which I don't care for . When I researched it , the recommendation from Ford was to crack the line at the slave cylinder ,let it drain ,refill ,tighten line . Then pull vacuum at reservoir for 30 minutes , break vacuum and top up .
Hope this helps . :)

[VENOM V]

The 2013 Camaros also went to a common reservoir. I'd be curious to know the pros and cons of this recent trend.

[Policy Limits]

How frequently should clutch fluid be changed on a car that is never tracked?

Same question on bleeding the brake lines?

[Bill Pemberton]

Great post Nine Ball , as track guys know that the fluid needs to be flushed frequently from the heat of the headers and other issues you mentioned. Sad to see this as the Mustang ( as noted)
has the same system and it is a royal pain for all the guys with Boss 302s ( we have the #2 Ford Store in the Nation across the street). Vettes, Camaros, Mustangs, etc. are using this, and it
was always a boon to be able to do the quick flush on a Viper. Hopefully bringing this up, it could possibly incorporate a change back for future models , since , like you, I can not imagine a
single real world advantage for this change?

[ACRucrazy]

I can not imagine a
single real world advantage for this change?

$$?

[Nine Ball]

I used my Mityvac and attempted to suck dry the brake booster reservoir, found another annoying thing. The brake booster has two chambers, one for the front brakes, the other for the rear brakes and the clutch feed. They have a wall separating the two chambers, with some small slits for the fluid to pass through. If you vacuum the fluid out, you can only get the fluid out of the rear-most chamber for the clutch. The front brake chamber is left half-full, and no way to get that fluid out. So, when you go to put in fresh fluid, it is instantly contaminated with what is remaining in the brake reservoir. Who thought of this crap?

Anyways, I sucked out the the fluid with the Mityvac, then went under the car and disconnected the feed line to the slave cylinder. Almost lost that little lock clip, it went flying when I pulled it off. Drained the feed line, then reconnected it to the slave. Filled the brake reservoir with DOT-4 fluid and pumped the pedal about 50 times to get pressure back. Everything seems to be working okay.

Tony

[ViperSmith]

Maybe a good first topic when they do an SRT Engineering chat here...