I'm lazy, just tell me what's wrong

[SpecialTool]

OK here's the drill. Clutch has pressure, then two or three pumps later clutch has no pressure. Wait five seconds, clutch has pressure again, two or three pumps later it's gone again. Etcetera, etcetera.

What's gone wrong? Master? Slave? Flexible link? Or (fat chance!) will a bleed fix it?

[Ron Hamperehill]

Sounds like contaminated fluid or a perished seal. Best hope is its contaminated fluid. Try bleeding it

[Matthew]

Does the clutch engage if you keep the pedal depressed?

Originally Posted by Alex

To check which end of the clutch has failed get someone to depress the clutch pedal then clamp the flexible clutch pipe (the one that leaves the slave). If the clutch stays down its the master, if it returns its the slave.

http://www.saabcentral.com/forums/sh...5&postcount=25
http://www.saabcentral.com/forums/sh...ad.php?t=49918

Any fluid leakage?

[AUSSIE900]

Perished O ring in slave , internal leak past seal . Loosing any fluid ?

[SpecialTool]

Thanks for the input, SAAB friends. There's no fluid loss; my bet is it's the master. Will do more investigating on the weekend and try Alex's clever test.

Did I mention that when I went to pop the bonnet after making it home yesterday, the latch mechanism decided to stop working? One of those days...

[SpecialTool]

Thought I would bleed the system first. Hooked up the trusty inner tube, loosened the bleed screw, pumped up the tube ... nothing. Took the bleed screw out ... no fluid escaping, under pressure or not. Why? Can a failed master, or slave, prevent fluid from flowing to he bleed screw?

( Decided to change the front brake pads while the car was laid up. Darn it, left CV boot was torn, so whipped out the axle. This old Aero is turning into a project car!)

[Rodentmaster]

I'm lazy, just tell me what's wrong..........

Global Financial Crisis
Global warming
Ongoing conflicts in troubled parts of the world
Fire
Floods
People losing jobs and-.......

Oh sorry,............ the CAR......?

[TooMany2cvs]

Originally Posted by Rodentmaster

Oh sorry,............ the CAR......?

That's the easy one. He broke it.

[THE ANORAK]

is the flexi rubber in the clutch line balloning when pressurising?

[SpecialTool]

Originally Posted by THE ANORAK

is the flexi rubber in the clutch line balloning when pressurising?

No, the flexible line feels firm and looks sound.

I went ahead and pulled the master cylinder since it's an easy job. Will overhaul that and see if it works but I suspect I'll soon be tackling my first slave repair.

[earthworm]

Its the master - these leak internally; if you were losing BF(brake fluid), then in all likelihood, it would be the slave..

Clutch hydraulics are the same as the brakes, but brakes very seldom leak BF..KOW ..knock on wood...

[SpecialTool]

Not much time to tinker today but I did take the master cylinder apart. Seals looked OK (will replace them anyway) but everything was coated with a gunky brown ooze so will give it a good clean.

I mentioned earlier that I couldn't get fluid to come out the bleed hole when trying to do a pressure bleed. Maybe the clutch line is also gunked up with bad old fluid? Tomorrow I will use a syringe to try to pump some clean fluid through the lines and out the bleed screw. Maybe I should start with a solvent -- will brake cleaner do any harm?

[TooMany2cvs]

Originally Posted by SpecialTool

I mentioned earlier that I couldn't get fluid to come out the bleed hole when trying to do a pressure bleed.

Have you removed the bleed nipple completely? One of my rear calipers wouldn't bleed through - I had to remove the nipple, and clear it out. The old stuff looked more like the contents of a heavy smoker's lungs...

Maybe the clutch line is also gunked up with bad old fluid?

Very likely.

Tomorrow I will use a syringe to try to pump some clean fluid through the lines and out the bleed screw. Maybe I should start with a solvent -- will brake cleaner do any harm?

The name isn't a coincidence... <grin>

[SpecialTool]

Yeah, took the bleed screw right out and poked around a little but no flow.

[TooMany2cvs]

Originally Posted by SpecialTool

Yeah, took the bleed screw right out and poked around a little but no flow.

Try standing on the pedal whilst the nipple's out... Bit of hydraulic pressure should free any gunk up.

I'm presuming you've slackened off the various unions in the line, one by one, from master to slave, and checked that you've got fluid coming to each?

[wokke]

Originally Posted by SpecialTool

I'll soon be tackling my first slave repair.

See my post on slave cylinder repair. http://www.saabcentral.com/forums/sh...d.php?t=150823

[SpecialTool]

Darn, not enough tinkering time lately, what with work and kids.

Just time today to rig up a little clutch system back flushing kit, consisting of a big syringe hooked up to the bleed screw via clear PVC. Pumped clean brake fluid back through the system and out the metal line where it joins the master cylinder (which my loyal readers will know has been removed for a rebuild).

The fluid first came out black and nasty, then gradually, over five or six syringes full, ran nice and clean. You bewdy!

Now to get myself a master rebuild kit, put it back together and see if I've got a working clutch again.

[AUSSIE900]

Special .. Good stuff re fluid ..

Put a kit thru both ... whilst doing is good ..

Be horrid to button it all up and then have to do slave .. for the sake of a few dollar seal kit ..

[SpecialTool]

Originally Posted by AUSSIE900

Special .. Good stuff re fluid ..

Put a kit thru both ... whilst doing is good ..

Be horrid to button it all up and then have to do slave .. for the sake of a few dollar seal kit ..

You're right Les, I was hoping to get away with a master cylinder rebuild -- done it before so in my comfort zone -- but still no pressure so I'll tackle the slave (next weekend! Bloody kids will take up the rest of this one).

Aah well, it will be a good learning experience -- one of the few jobs I haven't yet had to do on a 900.

[AUSSIE900]

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Aah well, it will be a good learning experience -- one of the few jobs I haven't yet had to do on a 900 


It will also be the easiest you have ever done , ,
Just becareful not to *nick * the new seals , I Use PBR rubber grease.