Replacing Clutch Fluid

[Vlad Soare]

Just skimmed this thread, and didn't see this mentioned anywhere: I've read that the hydraulic clutch in the S550 is a "self bleeding" system, such that simply pumping the clutch pedal 100 times or so would clear the line of old fluid.

So if you're really worried about old fluid in the line (you shouldn't be, and it'll eventually clear out from normal driving anyway), you could go ahead and give your left leg a good workout after bleeding the rest of the system.

I believe the "self bleeding" property just means that, given enough pedal pumps, any air bubbles that might be in the system will eventually migrate to the top. But that will likely not do anything to refresh the fluid itself.
Anyway, I'm not worried anymore. I understand I'll be fine. I'll just replace the break fluid.

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[Conman1138]

I believe the "self bleeding" property just means that, given enough pedal pumps, any air bubbles that might be in the system will eventually migrate to the top. But that will likely not do anything to refresh the fluid itself.
Anyway, I'm not worried anymore. I understand I'll be fine. I'll just replace the break fluid.

It was my understanding that it is a recirculating system, and the fluid bled out of the clutch makes its way back to the reservoir via a return line. Maybe I'm wrong, though.

Edit: I've been proven wrong, this is not how the "self bleeding" nature of the system works, fluid is not cycled through.

 

[sk47]

Just skimmed this thread, and didn't see this mentioned anywhere: I've read that the hydraulic clutch in the S550 is a "self bleeding" system, such that simply pumping the clutch pedal 100 times or so would clear the line of old fluid.

So if you're really worried about old fluid in the line (you shouldn't be, and it'll eventually clear out from normal driving anyway), you could go ahead and give your left leg a good workout after bleeding the rest of the system.

I believe the "self bleeding" property just means that, given enough pedal pumps, any air bubbles that might be in the system will eventually migrate to the top. But that will likely not do anything to refresh the fluid itself.
Anyway, I'm not worried anymore. I understand I'll be fine. I'll just replace the break fluid.

Hello; I get the same interpretation about air bubbles with the multiple pedal pumps. This does not replace old fluid is the way it sounds.

As for the "no worries" about old clutch fluid I can agree it will not bite you right away. Might take a few years longer. The 1989 ford pickup I mentioned was the first vehicle I owned with a hydraulic clutch. I was told not to worry about the fluid and wound up with a big job after several years. Seems many get away with no fluid changes for a long time.

 

[jacknifetoaswan]

It was my understanding that it is a recirculating system, and the fluid bled out of the clutch makes its way back to the reservoir via a return line. Maybe I'm wrong, though.

There is no return line to the master cylinder. It's a single plastic line that many people replace with a braided line.

The bleeding procedure only gets the air bubbles to the top of the master cylinder. It does not remove the fluid from the line and replace it with new fluid.

JR

 

[Conman1138]

There is no return line to the master cylinder. It's a single plastic line that many people replace with a braided line.

The bleeding procedure only gets the air bubbles to the top of the master cylinder. It does not remove the fluid from the line and replace it with new fluid.

JR

Thanks for clearing that up! I had a hard time imagining a true self bleeding system any other way. After doing some more reading, Ford's recommended procedure is to pump the pedal a ton of times while applying vacuum to the system at the reservoir, which corroborates your comment. So as you said earlier, the only way to actually clear that fluid out would be to disconnect the line at the slave cylinder and drain it, then pump it for half a day.

What a hassle.

 

[sk47]

Hello; Had TV tuned to Motor trend TV Sunday morning. A show called Two Girls Garage was on. They were doing transmission work on a Ford Mustang, I think. What caught my attention was that they "bench bleed" the hydraulic clutch (slave cylinder?) before installing it in the bell housing.
The clutch unit has a tube coming out of it which attaches to the line feeding hydraulic (brake) fluid from the master cylinder.

On the show they had a fair-sized bowl with brake fluid in it. The tube from the slave cylinder is submerged into the brake fluid. The slave cylinder is repeatedly squeezed (cycled) until no more air bubbles come out. After that the unit is installed in the bell housing. I do not know how they kept the fluid from dripping out, that was not shown. Maybe a rubber vacuum cap over the end???

Having replaced a Ford clutch master and slave cylinder myself such would have been good to know. I eventually got the system bleed, but it was a pain. This information will not help if the trans is already installed. But next time will be worth knowing.

 

[bnightstar]

Ok lots of discussion going but unfortunately just a few calls on this. Here is the Ford Manual procedure from my 2017 Workshop manual:

1.
Make sure all hydraulic tubes are correctly seated.
2.
Make sure the clutch pedal is in the most upward position.
3.
Check the fluid level of the brake/clutch reservoir. Fill the reservoir with the specified fluid to the MAX mark.
Material
: Motorcraft® DOT 4 LV High Performance Motor Vehicle Brake Fluid / PM-20 (WSS-M6C65-A2)
4.
Using a suitable bleeder kit and a Vacuum Pump Kit, install the rubber stopper in the reservoir opening. Make sure the rubber stopper has a tight fit. Alternate method: use a 50 mm (1.96 in) rubber stopper with an 8 mm (0.31 in) pipe inserted through the rubber stopper. Use the General Equipment: Brake/Clutch System Pressure Bleeder/Filler
5.
Holding the rubber stopper in place, operate the vacuum pump to 15-20 inches of vacuum. Hold the vacuum for one minute, then quickly relieve the vacuum. Remove the special tools.
6.
Check the fluid level of the reservoir. Fill the reservoir with the specified fluid to the MAX mark. Install the reservoir cap.
7.
Press and release the clutch pedal 10 to 12 times or until clutch pedal effort is consistent and positive at top of clutch pedal travel.
8.
Repeat Steps 4 through 7 two additional times or until clutch pedal effort is consistent and positive at top of clutch pedal travel.
9.
Install the reservoir cap. 10.
Check the clutch pedal reserve. Test the clutch system for normal operation.

With that been said the OEM fluid is good enough if you don't overheat it for 4 years based on the Ford Service Maintenance schedule. Something to note here is though if you overheat the brake fluid it's better to replace it and when you are doing this make sure they first bleed your brakes, then run the ABS air release procedure and finally do the Clutch bleeding procedure this is the correct way to do it. If you do brake fluid replacement but you don't bleed the ABS or Clutch you are risking of leaving air in the system and this will eventually find it's way to the lame clutch throwout bearing and you will need to replace that and it's expensive job I learned that the hard way last season. Hope this is helpful.

 

[Kane]

How I can tell if the clutch have the require amount of fluid?
I had RXT with throw out bearing installed several months ago & recently all gears get stuck except 5th & 6th when cruising, not sure if it's related to clutch fluid, but sometimes when it stuck on a gear I pump the clutch 2 or 3 times & the shift releases. Got MGW shifter & clutch line install as well.

 

[sk47]

How I can tell if the clutch have the require amount of fluid?
I had RXT with throw out bearing installed several months ago & recently all gears get stuck except 5th & 6th when cruising, not sure if it's related to clutch fluid, but sometimes when it stuck on a gear I pump the clutch 2 or 3 times & the shift releases. Got MGW shifter & clutch line install as well.

Hello; I cannot say specifically for your car but all hydraulic clutch systems i know have a reservoir. That reservoir needs to be mounted higher than the transmission so the fluid can gravity feed to the slave cylinder and master cylinder. To keep the system, compact that reservoir is usually mounted on the drivers side and often on the firewall. My guess is a semitransparent plastic type making it easy to simply look at to check the fluid level.

 

[Kane]

Thanks, yah it's with the brake fluid & it's pretty full .... Not sure what causing the gears to stuck like that

 

[sk47]

Thanks, yah it's with the brake fluid & it's pretty full .... Not sure what causing the gears to stuck like that

Hello; A hydraulic clutch system can have plenty of fluid and still not be functioning properly.

RXT with throw out bearing installed several months ago & recently all gears get stuck except 5th & 6th when cruising, not sure if it's related to clutch fluid, but sometimes when it stuck on a gear I pump the clutch 2 or 3 times & the shift releases. Got MGW shifter & clutch line install as well.

Hello; Read your other post again. Not clear to me what the issue might be. You seem to be saying sometimes you cannot shift out of a gear.

when you are doing this make sure they first bleed your brakes, then run the ABS air release procedure and finally do the Clutch bleeding procedure this is the correct way to do it. If you do brake fluid replacement but you don't bleed the ABS or Clutch you are risking of leaving air in the system and this will eventually find it's way to the lame clutch throwout bearing and you will need to replace that and it's expensive job I learned that the hard way last season.

Hello; My knowledge apparently is not up to date on the Mustang hydraulic clutch system. Went back to the above post. This seems to imply the brake and clutch hydraulics are somehow combined. Common reservoir perhaps?? Afraid this does not make sense to me but a number of things on new cars do not make sense.

A show called Two Girls Garage was on. They were doing transmission work on a Ford Mustang, I think. What caught my attention was that they "bench bleed" the hydraulic clutch (slave cylinder?) before installing it in the bell housing.
The clutch unit has a tube coming out of it which attaches to the line feeding hydraulic (brake) fluid from the master cylinder.

On the show they had a fair-sized bowl with brake fluid in it. The tube from the slave cylinder is submerged into the brake fluid. The slave cylinder is repeatedly squeezed (cycled) until no more air bubbles come out. After that the unit is installed in the bell housing. I do not know how they kept the fluid from dripping out, that was not shown. Maybe a rubber vacuum cap over the end???

 

[Kane]

Yes that's what i meant.. it's a common issue in MT82 usually on the 3rd gear, the shifter stuck on 3rd you can't move it to any other gear smoothly (the shifter stuck on gear, you would have to yank it out of the a gear to whatever other gear u want to shift to).

When I said sometime, i meant not always does that but recently it's kinda more frequent.

 

[Nightmonkey]

How I can tell if the clutch have the require amount of fluid?

The reservoir is shared for brake and clutch.
How did you bleed it?
If you did like the workshop manual says (vacuum pump etc.), just do it again.
If not, follow the manual.

 

[sk47]

Hello; To the OP, guess your situation sort of boils down to a poorly bleed hydraulic system or some instillation problem with the new parts recently installed.
bnightstar gave you a procedure to try for bleeding. I would try that and look for other ideas on bleeding first.

good luck

 

[Kane]

Hello; To the OP, guess your situation sort of boils down to a poorly bleed hydraulic system or some instillation problem with the new parts recently installed.
bnightstar gave you a procedure to try for bleeding. I would try that and look for other ideas on bleeding first.

good luck

The parts installed while ago with no issues, i have them inspected them later when I started getting more stuck gears, not sure if it's MGW shifter thing or clutch or just MT82 being MT82 .. I'll probably start new thread about this issue if I couldn't get qn answer..
Thank you

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