Doooottttttttt, where are you???

[Dot]

Dot;

sorry, can we clarify some points please;

no trouble pushing it in it was disconcerting to me because when I tried to engage the clutch to go down from 6th to 5th the pedal went straight to the floor (no resistance) It didn't disengage the 6th gear (it stayed in 6th)

Does "no trouble" mean;

1 it felt just like normal. (ie nothing felt wrong)
2. it was not hard and I didn't have to press normally; like it just no pressure at all When I tried to go from 6th I put my foot on the clutch and it went straight to the floor, there was nothing there

And does: " It didn't disengage the 6th gear (it stayed in 6th) " Yes it stayed in 6th


mean, when I have the pedal pressed, I couldn't shift the out of 6th. ie the lever wouldn't move? Correct, the gear stick did not move..

[BruceS]

???????????????????? more time needed playing with the stick??????????????????
(it'll move! Won't it Steve??)

[Dot]

???????????????????? more time needed playing with the stick??????????????????
(it'll move! Won't it Steve??)

Who said anything about playing with a stick? Maybe a twig

[Newcastle George]

I had slightly similar clutch problems to Dot earlier this year and replacement of the hydraulic/air servo as the one in Dot's picture with the sticker on solved the problem with comparatively little expense. I will look thru my records to find what I paid for it including freight.

George

[Dot]

I had slightly similar clutch problems to Dot earlier this year and replacement of the hydraulic/air servo as the one in Dot's picture with the sticker on solved the problem with comparatively little expense. I will look thru my records to find what I paid for it including freight.

George

Thanks George, do you know what the exact prob was at all??

[Newcastle George]

No Dot, but when I enquired re a repair kit I was told that a complete replacement cost much the same. I had spent quite some time bleeding the system on several occasions only to have the problem reoccur.

Just checked, the replacement cost including freight was $117.70

George

[jon_d]

Thanks Dot.

I

oes "no trouble" mean;

1 it felt just like normal. (ie nothing felt wrong)
2. it was not hard and I didn't have to press normally; like it just no pressure at all When I tried to go from 6th I put my foot on the clutch and it went straight to the floor, there was nothing there

And does: " It didn't disengage the 6th gear (it stayed in 6th) " Yes it stayed in 6th


mean, when I have the pedal pressed, I couldn't shift the out of 6th. ie the lever wouldn't move? Correct, the gear stick did not move..

That makes it clearer.

I would be following George's suggestion.

Replace the slave and I'd replace the master clutch cylinder too. (one is probably gone and the other might be equally as worn.)

They are probably old cast iron sleeves which has a bit of rust on them and the rubber is torn. Allowing the hydraulic fluid to bypass.


A good test is to gently press on the pedal; not hard to activate it... and see if it slowly sinks to the floor. (Might take a minute or two).

If it does, it most likely is the master cylinder.

[native pepper]

As I said previously, it's more than likely to be a sticking valve and the mechanic seems to agree. It's probably the air release valve which may also handle the hydraulic side of it, hence sometimes when you push the clutch it goes to the floor as the hydraulics need air to apply its pressure. It may be a totally different system to what I've experienced, but the air clutch release valves build up air to operate the clutch and when the clutch is released it drops the air. It may not be closing at times and so there is no buildup, so no clutch and jammed gears. You'd have to be moving to disengage the gears, then you could crash change drive it using the engine revs. When the vehicle sits for awhile, the valve closes and it will work, but after awhile as the system reheats, the valve will fail and you have the same problem. Then again it may be an entirely different problem, air clutches are finicky things and can be prone to many problems.

[bagmaker]

I am pretty sure their system is an air-assisted hydraulic clutch, it looks exactly the same as mine -although on a RoadRanger gearbox.
The theory is kinda in reverse to a vacuum boosted brake system, with a strong leg you can actually push the clutch in and do the business but compressed air is added at the slave end to amplify the foot pressure.
Its probably some debris has damaged a seal in there, thus intermittantly allowing full air pressure to over-ride the foot pedal position (it went to the floor) -its also possible the system has been overheated, fluid dropped or water has attacked the fluid degrading it to a state which allows it to boil every now and then.

Dont know, CSI time, post mortem.

The above conjecture being the case, grab some new fluid from the Alice auto shop, drain the old stuff at the slave and top up / bleed through new fluid -there should be a reservior up above the pedal, under the dash- ensuring no air in the line.
Once done the old girl can be given a few large laps of Alice to prove confidence then head to downtown Hadelaide for a rebuild.

In an emergency you CAN muscle such a clutch for start -offs (and crash-box the other gears using the usual techniques) if the air boost fails totally on the road home.

[jon_d]

It's air over hydraulic.

As Wyane said, the air just amplifies it.

A question to ponder:

If the foot and clutch pedal went to the foor; did the clutch fork/arm move?

From Dots desciption, logic says it didn't. The air side can be excluded becuase the foot has gone to the floor.

We need to idenfiy why the foot went to the floor, but the fork/arm didn't disengage the clutch.


Dot; if you look at the pictures there is an inspection cover ontop of the bell housing. It may be worthwhile taking it off and taking a photo of the fork arm.

This will help confirm that there is nothing wrong with it. .... just an idea.... but I was sort of left field with the shiny bit!