I'm screwed - bleeding my Subaru's clutch

[fbrdphreak]

Car: 2006 Subaru Legacy GT 5-speed

So, I was having my fiancée help me bleed the clutch and in a moment of sheer stupidity, I had her pull the pedal back up from the floor while the valve was open. Tada, huge amount of air in the system!

So, the pedal now flops between up & down and has zero pressure. I have spent the last several evenings trying to bleed the clutch with a vacuum pump, unsuccessfully.

A little background: I replaced my clutch around 70K (currently at 74K) with an ACT HD clutch/pressure plate and 06/07 WRX flywheel. At the time, I adjusted the clutch pedal so it was easier to drive. Once it broke-in, I adjusted the clutch pedal back to where it was (I think).

Here is my process:

*Attach vacuum pump system (system looks like this) to bleeder on slave cylinder (I've tried master too, but primarily slave)

*Pump clutch pedal a handful of times & prime vacuum system with 20-25 inches-Hg

*Open bleeder screw

At this point, a limited amount of fluid is sucked into the hose. Some air is sucked past the bleeder screw, which I can tell because of a consistent flow of large sized air bubbles. If I'm lucky, I will get a rush of super small bubbles and a few mL of fluid into the hose.

*Close bleeder screw, pump clutch pedal again, start from the top

Through this process, I have gotten about 100mL out of the system, mostly through the slave. I got a little out of the master cylinder, but it's not consistent or in any great volume.

I was giving it another go this evening, and now I'm not able to get ANYTHING out of either the slave or master. I was getting tired and frustrated, so I could've been doing something wrong or just plain hallucinating.

Despite bleeding 100mL of fluid, the pedal has not changed AT ALL.

I have also tried gravity bleeding (over night) with zero effect. I have tried moving the slave pin manually while applying vacuum; this ejects some more fluid & some bubbles, but not a huge amount.

Here are my next steps:

*Try adjusting clutch pedal rod to see if I can get it to move more fluid when the pedal is actuated

*Have it pressure bled with a compressor & appropriate fittings (I do not have this - would have to come have someone do it)

*Have the car towed to a shop for them to eff with it

Does anyone have any suggestions? Am I missing anything?

 

[thedarkwolf]

I pressure bleed mine and don't use any special fittings. I have a spare master cylinder cap that I drilled a small hole in that I just shove an air gun into.

You can try putting some pipe tape on the threads of the bleeder to keep the vacuum bleeder from sucking air.

Speed bleeders are awesome. I've never used one for my clutch but I have them in both my cars for the brakes.

You can drive it without a clutch. Just have to kill the engine every time you stop and use the starter to get it moving again. No need to get it towed.

 

[fbrdphreak]

Yeah that's what I was referring to, just a cap that pressurizes the master cylinder. I thought about trying to make my own, but the only external air pressure source I have is a small 12V compressor. I don't really want to buy a proper compressor just for this - I don't have a use, space, or money for it.

Yeah I've tried teflon tape which doesn't seem to work well, but grease does (for a time). I don't think that's the issue, but I will take another swing at it on Sunday.

I *do* have speed bleeders waiting to go in my calipers - I wonder if they are the same size as my clutch bleeders

 

[exdeath]

Is the master anything like a brake master that has to be "bench bled" by itself? Possible air in the master cylinder itself, you can't bleed that the normal way you'd bleed a line/slave.

 

[fbrdphreak]

It's exactly the same. The clutch master cylinder is operated via the clutch pedal, actuating a rod that compresses the fluid in the master cylinder. The pressure generated goes down a hard, bent line metal line into a flexible metal line and into the slave cylinder. The slave cylinder is a small metal structure that has a large pin sticking it out of it. The fluid then presses the pin into the shift fork on the transmission, actuating the clutch.

From some other feedback I've gotten, I think bench bleeding the master is my next step. Then I'll reattach the master, clamp the slave pin down, and bleed from the slave with my vacuum system.

This is going to be a fun Sunday!

Keep the feedback coming folks

 

[NutBucket]

Is the master anything like a brake master that has to be "bench bled" by itself? Possible air in the master cylinder itself, you can't bleed that the normal way you'd bleed a line/slave.

I'd go with this. Most likely cause. Bleeding with a vacuum pump is a no brainer which leaves this as the best explanation.

<-- '05 GT owner

 

[fbrdphreak]

Well folks, I have given up.

I pulled the master and as far as I can tell, successfully bled it. I reinstall it and the pedal is ever so slightly improved. It still sucks straight to the floor, but it doesn't land with a resounding thud.

First I tried vacuum bleeding the slave as usual. Pumped the shit out of the clutch pedal. Attach vacuum system and build up 20-25 inHg. Compress slave pin as much as possible. Open bleeder.

I get a bit of fluid and a lot of small bubbles. Eventually this flow stops (even though it's under vacuum), so I close the bleeder and re-pump the clutch. Oh noes, the clutch pedal is just as dead and floppy as before! MOTHERWTF??!?!!?!!

So I pulled the master AGAIN and bench bled it AGAIN so I could retry with just gravity bleeding. Clutch pedal is again slightly improved after bench bleeding, so I pump it up, put a hose on the slave bleeder, and open the slave bleeder. A fair amount of bubbles with very little fluid. Close bleeder and go back to the clutch pedal - IT'S DEAD AND FLOPPY AGAIN. :twisted:

And, I'm throwing in the towel. I suppose if I was so inclined, I could pull the entire system (there's only one additional mounting point for the hard lines, and they are very short lines) and try to bench bleed THAT, but I fear that too would be fruitless.

I'm calling a guy I know to see if he's able to bring a portable compressor and pressure bleeding system, otherwise I'll have it towed to a shop.

 

[66type2]

Boy, can I identify. I'm having the same issue on a '99 Outback. I'm stumped. Years ago I knew a mechanic who had a pressure bleeding system which operated off of tire pressure. I'm going to see if I can locate one, before I too call for a tow to the garage. Whatever the drawbacks of mechanical clutch linkages, I wish Subaru had them. I never had problems like this with my GM, Chrysler, or VW vehicles.

 

[jlee]

66, what are you using to bleed? I have a Mityvac vacuum pump and I bled my MR2's clutch without a problem (after replacing the master).

 

[thedarkwolf]

Again you don't need a working hydraulic clutch system to drive the car. You push the non-working clutch pedal down to start the car and get it moving forward, the starter is a lot stronger than you think. Mine was able to get my miata moving and started on a very steep hill when my clutch hydraulics went out. Once the car is moving you just have to rev match to shift and kill the engine when you come to a stop. You look a bit stupid doing it but you can drive it without have to pay a tow truck.

 

[Doppel]

Is your fiance like every other female on the planet who, when asked to assist with bleeding brakes or clutch, hems and haws as severely as if a regular person were asked to till a field by hand with only a shovel?

 

[leper84]

Try this (cant remember for the life of me what the clutch hydraulics look like on a scooby so dunno what room you're working with)-

Bench bleed master as best you can, install it.

1) Have your girl hold the pedal down. Crack open the line going out of the master. Close it after nothing comes out. Tell her to lift the pedal. Repeat until there is no air.

2) Move down to the line going into the slave. Same thing- she holds the pedal down, you crack open the line and close it, she lets up. Do this again till no more air.

3) Manually bleed the slave, pumping and holding the pedal and what not.

It sounds like you have a crapload of air in the system. Doing that should step by step take air out of every single part.

The only other thing I can think of is you might need to pull a vacuum on the master itself. If after going through those steps you still have crappy pedal, find a rubber stopper that fits into the top of the master and has a hole for the vacuum line from your bleeder. Pull 20 in/hg and wait one minute. Release the vacuum and pump the pedal 15-20 times. Repeat that a couple times.

If all that doesn't work then you probably dislodged a seal in either the master or slave and the fluid is just leaking on by. If you didn't replace both with your clutch at 70k, you should have and this is probably a good excuse to...

 

[OILFIELDTRASH]

Is your fiance like every other female on the planet who, when asked to assist with bleeding brakes or clutch, hems and haws as severely as if a regular person were asked to till a field by hand with only a shovel?

Lol. Don't dare buy the tools needed to do the job or pay someone to do the job for you either.

 

[fbrdphreak]

Sorry, I didn't post the finale to this. Here's my post on the LGT forum:

To close this out, I had a mechanic I know come by to finish this. He had a cool little system that uses the air from your tire to pressurize the system - neat eh?

He had some trouble at first as well and it turned out that the master pin was advanced in a little too far and was blocking the port. He pulled the master cylinder off the firewall a bit to pull the pin out and it bled like a charm.

 

[RearAdmiral]

Sorry, I didn't post the finale to this. Here's my post on the LGT forum:

To close this out, I had a mechanic I know come by to finish this. He had a cool little system that uses the air from your tire to pressurize the system - neat eh?

He had some trouble at first as well and it turned out that the master pin was advanced in a little too far and was blocking the port. He pulled the master cylinder off the firewall a bit to pull the pin out and it bled like a charm.

Solution: turn gay so you can have a guy to help you.

 

[compman25]

Solution: turn gay so you can have a guy to help you.

Says the RearAdmiral!!!

 

[Howard]

Says the RearAdmiral!!!

I'm sorry, do you have something against seamen?

 

[RearAdmiral]

Says the RearAdmiral!!!

Sorry for my naval ranking.