Ranger Clutch Fluid Change procedure?

SINISTER

Watched some videos on bleeding our clutch fluid. Some people have had success some have not. Problems are speculated as being either pumping too quick, holding the drain open too long or at the wrong time, etc etc....

What about an alternative? Coming from the Corvette world we almost exclusively used the "Ranger method" watch the video below. Essentially you change out the clutch fluid reservoir, pump the clutch 15 to 20 times, then change it out again ...multiple times....see second half of video for procedure.

If done often keeps the fluid clean and your constantly introducing new clean fluid if done regularly.

Can someone please inform me why this method does not work on the 370z and why it does on the Corvette....in this case there is no possibility of problems nor air bubbles in the system associated with the bleed under the car version...

See video below...

SINISTER

Anyone with knowledge on our clutch fluid system want to comment on this procedure? Pros/cons?

need4speed255

I have done this same method on my eclipse. It will work the same on the Z. It's just a simple hydraulic system. The only problem with the ranger method is that there may still be contaminated fluid in the slave and the lines. The pumping of the clutch numerous times may get most or all of it out if repeating the steps until the fluid is clear. Definitely better than not changing the fluid.

SINISTER

I believe that what your saying is true if all you did was replace the fluid however the pumping of the clutch 30 times and then changing the fluid again and again...until clear is essentially clearing out all the fluid especially if done on a regular basis....


-1
Change the fluid in the clutch master cylinder reservoir.
(a) Draw out the discolored fluid with a syringe, keeping the corrosive fluid off your paint.
(b) Wipe down the reservoir and the diaphragm on the cap, using a clean, lint-free towel.
(c) Locate the fill-line in or on the reservoir.
(d) Refill the reservoir to just below the fill-line with fresh fluid specified in your owner’s manual. Do not over-fill. If the reservoir has both minimum and maximum marks, suggest filling to the midpoint.
(e) Clean the diaphragm if dirty and properly seat it on the reservoir cap.
(f) Replace the reservoir cap snugly.

-2
With the engine off, pump the clutch pedal full-top to full-bottom to full-top 30 times. This action causes fluid in the clutch hydraulics to circulate, blending the new and old fluid, and revealing the color of the blend. It also helps scour residue from the actuator (slave) and displace upward into the reservoir any air trapped in the hydraulics.

-3
Then, re-inspect the blended fluid in the reservoir. If it is totally clear and shows zero murkiness, you are finished. If it's not, restart at (2). Continue to change the fluid as many times as needed, with the full, slow top-to-bottom-to-top pedal pumps between changes, until it remains absolutely clear and clean. Getting the fluid clean the first time is the hard part.

-4
Next come the easy part, keeping it clean. Re-inspect the clutch fluid each time you add gasoline or prepare for spirited driving, including the track. If it is not still clear and clean, restart at Step-2. Usually will take only two or three swaps to get the fluid pristine again.

SINISTER

I am unsure if the 370z clutch hydraulics work the same as the the corvette. If it does (I suspect it does) then this method can be performed regularly versus the flush and bleed (which you need an assistant -who follows instructions perfectly , you need to get under the car, and you run the risk of air getting into the system)...If anyone knows please comment.

The corvette clutch hydraulics work as follows.

The clutch hydraulic system consists of a master cylinder and an actuator cylinder.

When pressure is applied to the clutch pedal (pedal depressed), the pushrod contacts the plunger and pushes it down the bore of the master cylinder.

In the first 0.8 mm (0.031 in) of movement, the recuperation seal closes the port to the fluid reservoir tank, and as the plunger continues to move down the bore of the cylinder, the fluid is forced through the outlet line to the actuator cylinder mounted to the driveline support assembly.

As fluid is pushed down the pipe from the master cylinder, this in turn forces the piston in the actuator cylinder outward.

As the actuator cylinder moves forward, it forces the release bearing to disengage the clutch pressure plate from the clutch disc.

On the return stroke (pedal released), the plunger moves back as a result of the return pressure of the clutch.

Fluid returns to the master cylinder and the final movement of the plunger opens the port to the fluid reservoir, allowing an unrestricted flow between system and reservoir.

Summary: Clutch fluid circulates between the master and actuator (slave).

Note: The volume of fluid in the entire system is a very few ounces. One ounce is in the master cylinder reservoir until diminished as you depress the pedal and create the flow described above.

SINISTER

He goes further with an explanation of the bleed alternative:

Alternative: Have the clutch hydraulics bled. This takes a competent technician about an hour and requires a lift. Cost is around $125. But the procedure includes some inherent difficulties:
• A hard, constricted reach with a tool to loosen the bleeder valve in its barely accessible position.
• A messy job because fluid dribbles into the bell-housing and all over adjacent surfaces.
• Need for two people, one at the bleeder valve, the other at the clutch pedal; or, if using a pump tool, the other keeping the clutch reservoir filled.
• if not done right, residual air will remain in the hydraulics, causing continued pedal issues.
• if crud has built up in the actuator (slave), a simple bleed won't dislodge it.
• Under the best of circumstances, the clutch will need bleeding each time the clutch fluid deteriorates. Not a cheap approach.

Our bleed is easier...as the bleeder valve is not as difficult to reach, not messy. However, the need for two people and the possibility of residual air remaining in the hydraulics if done incorrectly can cause problems...

SINISTER

Looks like this was discussed in the past and is being used at least by this forum member...

How soon to bleed clutch?

nis350

i don't think the fluid circulates between the cmc and csc. there is no return line from the csc (bottom) to the cmc (top).

the fluid at or near the csc (bottom) can't return to the cmc on the top.

SINISTER

What you quoted is actually a quote on how the Corvette system works from their service manual and quoted by Ranger.
It is definately the way the corvette system works....
But your saying that this is what is different with the 370z and the Corvette system?

nis350

I'm sorry. I don't have any knowledge about the vette.

The diameter of the brake line is very small and I just don't see how the fluid at the bottom of the system (csc) get back up to the top (cmc) without a return line from the csc to the cmc. The fluid only travel one way which is from the cmc to the csc.

The same can be said about the brake system. The fluid at the calibers would never get back up to the master cylinder.

SINISTER

Interesting....so no return or outlet line. I see that makes a bleed necessary...
Maybe this is good for some ongoing maitenance to keep it fresh but to get it all cleaned out a flush/bleed sounds like it is necessary...
Thanks!

JARblue

I've had reasonable success bleeding the clutch with just a gravity bleed. Ranger method as much as possible, fill up master reservoir with new fluid, gravity bleed until master is almost empty, close bleeder valve, refill master, and pump clutch pedal (SLOWLY!) until pressure returns. It takes a while, but I can do it by myself.

I typically ask my wife (or helper) to help pump the clutch pedal while I'm down at the bleeder valve though - it's much faster than the gravity bleed process.

And yes, I can confirm there is no return line or clutch fluid circulation in the Z. Definitely want to do a bleed if the fluid is looking bad - dirty fluid can cause internal seals to fail (typically on the master).

__________________

SINISTER

I will be doing this soon...

SINISTER

So you still do the ranger method just as an ongoing maintenance? ....I suppose I will do this also along with the bleed too! Thanks

Fountainhead

Hi All,
Open the Clutch Master Cylinder reservoir lid and have someone press the clutch in and out and you will see the fluid of the MC reservoir moving as you cycle the clutch. Think about it, where will the volume of fluid pushed into the CSC return to after actuation? The CSC rides against the Clutch fingers and CSC is normally depressed about 50% position. When the clutch pedal is pressed the CSC fully extends and presses the clutch fingers in about ~0.5 to 0.75 in. When the clutch pedal is pressed in and released, the CSC returns to 50% position. The volume of liquid used to increase the CSC position has nowhere else to go but back into the master cylinder. CSC fluid is constantly changing location from the CSC back to the Clutch master cylinder reservoir.

Brakes only travel a fraction of an inch to press the calipers and the volume of liquid moving is far far less, traveling 5x the distance of the Clutch fluid so there is really no noticeable change/fluid volume change in the brake reservoir.

So in short, the Clutch fluid does move around and is not trapped entirely in the CSC.
Brake fluid is trapped at the Caliper cylinder and cannot move back to the Brake master cylinder.

yes I still regularly change my clutch fluid and for 5 years have used DOT 3/4 Valvoline and so far no problems. It's clean as a whistle. I never let it get even slightly dirty.
I usually empty the master, fill it up, pump the pedal about 12 times then empty the master and fill it back up again. I suppose one day I'll bleed the CSC from the bottom but I will only do so to find out if it has foreign bodies *clutch dust* in the bottom. If the video guy had pumped the clutch about 12 times after the initial fluid removal/addition you would have seen the dirty fluid returning to the master reservoir after a few pumps. Honestly mine has never been dirty enough but to barely see the fluid is contaminated, so I doubt mine is dirty down at the CSC.
If it had been black and chunky I would have bled from the bottom. I may still bleed from bottom, and report back here but I expect to see clear fluid.