Air in the clutch system?

[Tom2000]

I started having trouble getting into gear as the clutch (despite being pressed) wasn't working properly..

It turned out that I had a leak from the Master Cylinder, I stripped this out and replaced it with a new one, I also replaced the Slave Cylinder for my own piece of mind and the copper wire inbetween the two. All parts sourced from RimmerBros, correct for my car.

I bleed the system, which i've never done before, put all the interior back, started her and found that although better I still had to pump the clutch alot..

I presume this is because I have air in the system still? - Everything is done up correctly and there are no air or fluid leeks anymore..

[Ben Baxter]

Yup, sounds like there is still air in the system somewhere along the line, pumping the pedal compresses it and when it is left for a while the air expands again needing compressing again and so on ...

Idiotic checks that I had to make when I replaced all the seals - Is the slave cylinder bolted on with the bleed nipple at the top? Can be bolted on upside down and an air lock can form above the nipple then. Did you keep the clutch depressed when tightening up the bleed nipple for the last time? If you let go of it then it can suck air back into the system. Did the clutch reservoir empty at any time during bleeding?

Probably easiest to just flush a load of new fluid through anyway, won't harm anything and ensures that you have nice new fluid in there, and no air bubbles at all.

[toomanyprojects]

Tom,

As stated over, very important that bleed nipple is at the top otherwise you'll never get all the air out. Also as over don't let the reservoir empty, If you do you have to start again!

Bleeding is easy but if you do things wrong then it's easy to end up with a little air in the system, and it doesn't take much...

Make sure you follow this sequence religiously

Open Nipple
Press Peddle all the way down
Close Nipple
Release Peddle
(and repeat)

Regardless of what else you do the peddle should never move upwards whilst the nipple is open.

It's best to put a clear tube on the end of the nipple so you can see any air bubbles that come out, I normally do three pumps without any air bubbles before I am happy.

It's probably exactly what you've done, so apologies if I have just told you what you know, but always good to start with the basics...

[Tom2000]

Believe the S/C is wrong way up :D cheers for the heads up!

[Tom2000]

ok so this is really really annoying me now, i've bleed her 3 times, doing it the correct way and refilling fluid at the end of it and she is still giving me problems..

ARGH

SOMEONE HELP!!!

[Deleted User]

re filling the fluid at the end of it? you need to keep it pretty much fully topped up all the way through preferably? 2 man job too unless you have one of those 'one man bleed system'

[Tom2000]

Jony5 wrote:

re filling the fluid at the end of it? you need to keep it pretty much fully topped up all the way through preferably? 2 man job too unless you have one of those 'one man bleed system'

oh ok, sorry this is all new to me.. surely its a three man job, one filling up, one bleeding and one pumping?

I didn't realise this.. common sense I suppose otherwise if u let it go empty.. the air will get in again? lol  ::)

[Deleted User]

yup u got it spot on, and ye 3 man if you wish, i just bought one of those kits i mentioned and ca do it on my own now as none of my family are interested in helpin lol you just have to be able to lean round and be able to pump the pedal and keep it topped up hehe

edit, easily avaliable from halfrauds or such if you still have no luck

[Tom2000]

cool, so you reckon the system will be clear if i keep it filled up to the equivelant of three filled resevoirs? appreciate it

[toomanyprojects]

Now I'm completely confused!!!!

You don't need 3 people, you don't even need 2 although it helps????

If you've got the tunnel out you can open the bleed nipple whilst operation the clutch peddle (can't you????)

Use this updated sequence and see how you get on.

Open Nipple
Press Peddle all the way down
Close Nipple
Release Peddle
Get out and top up resevoir
(and repeat)

[rotoflex]

Also:  

You don't have to open the bleed nipple more than just enough to let fluid out when you press the pedal.

If you use a piece of transparent tubing, you can see the bubbles coming out & get a better idea of what's going on.  If you arrange the tubing so that you've got an upside-down 'U' (fluid comes out of the nipple, goes up the tubing a couple of inches, turns then goes down to go into a receptacle), you create a sort of backwards 'plumber's trap' to guard against air going air going back into the bleed nipple.  Since there's a short column of fluid in the tube above the nipple, if anything gets sucked back in it will be fluid.

[Ben Baxter]

Toomanyprojects has got that down wonderfully, always done it by myself though obviously a touch easier if you've got someone else to save you having to get out of the car after each cycle.

You only really want to "un-nip" the bleed nipple, quarter of a turn anti-clockwise is normally about right, keep your hand on the spanner (a flare nut wrench is even better - doesn't fall off as often!), then push the pedal down, close the bleed nipple back up and let go of the pedal. Jump out, check fluid level in reservoir (one pump of the pedal shouldn't empty it) and repeat! Can't really do it too many times so if you think you've got a little bit of air still in there somewhere then just keep on doing it.

Should be a lot easier to do with the gearbox tunnel removed now you've got the nipple on the top too!

[steadyg]

Better still use one of these. Brilliant !

Garry.

[Deleted User]

thats what i was tryin to say but seemed to fly over everyones head, have one of the 'one man bleed kit' or something from halfrauds, works like a treat!

[Tom2000]

Jony5 wrote:

thats what i was tryin to say but seemed to fly over everyones head, have one of the 'one man bleed kit' or something from halfrauds, works like a treat!

Or save the bother of buying one and get other half to pump clutch :)

[Deleted User]

ye but its still just easier, no pissin about opening and closing the bleed nipple, can do it when no ones around......

[willcolumbine]

Don't see what the big deal is - you can quite happily sit in the car pump the clutch and 'ahem' tweak the nipple. There is enough in the reservoir for a few good pumps then you just fill it up when done. By the way if you've replaced the slave master and pipe / hose and it still dosent feel good and there's no air coming out then you might want to make sure you've still got a pivot pin. One of those things I've learnt from experience!

[Deleted User]

what about brakes..........and cant do clutch if the tunnel is still in........

[rotoflex]

I just use the upside-down U tube.  Bubbles go up through the fluid in the tube, fluid can only come back in (after the 2nd stroke).  Fluid level in the reservoir must still be closely watched, of course.