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Exbury
01-01-2007, 01:25 PM
Well, after the gearbox rebuild (and wishing I had not disturbed the clutch line, I have a few problems with rebleeding the clutch and getting it to work.

Actions;
Dismantled the clutch at the flexible hose (clamped) during the gearbox removal (with Hindsight, probably best not to do this as the system should be able to be unbolted and remain above the gearbox during removal.
Upon rebuild & re-connection, tried to hand bleed the system, however as soon as the pedal was touched it sank to the floor and no further travel. Even after several attemps and tryign to bleed at each join, the pedal keeps on sinking.
Unbolted hardline, piston etc complete from gearbox and raised as high as possible, rebleed and replaced. Pedal now sinks nearly to the floor with 1"-2" of travel by foot to partially move the clutch release arm.
Got a pressurised brake bleeding system and did it all over again, new fluid and redoing the above.

No difference - I now have a pedal that when touched the spring kicks in and it sinks to the floor, the little bit of travel 1-2" by foot which moves the piston on the gearbox a little.

Noticed - Have noticed that if I push the piston on the g/box with my finger it goes in easily and fluid builds up in the master cylinder. I was expecting that the unit between the piston and the flexible hose is a proportioning valve and that when I push the piston in, the valve will allow only a little fluid to return slowly (although saying that might cause clutch engaging problems!?!).
Also when pedal is brought back up by hand, the piston on the g/box end moves in.

My initial thoughs are that where the clutch line runs UP from the Clutch cylinder, before going DOWN to the flexible hose, air is still trapped in this section, which is why the pedal sinks as air is more compressible than the fluid and the spring on the pedal is stronger than the air. This is why I do not get the power in the hydraulic system I should.

Tested - I have tested the clutch engage/disengage with a bar, seems to work, the gearbox selects all gears when the release arm is put into position etc.

As the clutch line is hidden behind the brake lines, I was thinking of making up a new copper line, bleeding it all ABOVE the clutch master cylinder, then bending the line down and fitting without disturbing the system again.

Otherwise any other thoughts before I take it to a garage, I need some experience or possibilities please? Thanks, Jason

BraindG
01-01-2007, 01:33 PM
from my experience this is quite normal, it settles down after a bit of driving and returns to normal. Each time ive done work on the clutch I found that the pedal would go right in, and not come out again... you would have to use your hand to pull it out again.

After much cuffufalige and rebleeding i found that it will stabalise within an hour.

Exbury
01-01-2007, 02:09 PM
Cheers Mate, unfortunately after two weekends and a few hours trying I still have no luck. As the pressure will not actually do the business and push the piston rod to fully engage the clutch I think I may try putting another line in as a test, if you are saying that this is fairly normal....at least you have made me a little more confident! I will probably keep pressure bleeding it and recirculating the new fluid in the system until all the air is out.

Cheers, Jason

BraindG
01-01-2007, 02:15 PM
yeah, sounds like a plan - I didnt realise it was an issue for so long for you.

When I do it I have someone push the clutch in while i tighten the bleeding bolt.

Exbury
01-01-2007, 02:16 PM
Actually, a quick Question, do you bleed the system with the pedal up and the piston rod in place, or different ways?

Thanks, J

BraindG
01-01-2007, 02:17 PM
When i do it, i just get someone to push the pedal while i tighten the bleeding bolt, rinse/repeat about 3 times.

Exbury
01-01-2007, 02:42 PM
Cheers for that, will give that a go next weekend. J :)

richy rich
01-01-2007, 03:42 PM
i find the best way to do this is blead it as you would brakes,but you might need to use your hand to push and lift the ped, after you get some ped then just sit there and pump the ped it will improve after loads of presses.

Exbury
01-01-2007, 04:41 PM
Cheers Rich, I didn't want to disturb you over Xmas and although fitting was a bit of a pain, the gearbox went in ok. Will retry the bleeding over next weekend with a good supply of brake fluid!
Cheers, J

Exbury
07-01-2007, 11:27 PM
BIG TIP - Dont try to bleed the clutch with the front end jacked up. Well after 2 days of trying this way (including pressure bleeding it) I still couldn't get the clutch to work. Tried bleeding the clutch on the level and while not 100% happy yet, the clutch now works. One fixed gearbox (quiet), new clutch plate, new fluid all for less than £200.00 :happy:

BraindG
07-01-2007, 11:36 PM
:2thumbsup - Excellent, thats how i did it aswell, didnt realise it being off the level would cause any problems.

Good to hear its back to normal /toycar