Lost pressure in clutch pedal

[JDM22]

Hi all,

I have a 96 gq Td42 wagon. The clutch has been going on it. Last week on the way home from work I lost clutch pedal pressure. I could get it back by pumping the pedal a few times but pressure would go again after a few seconds. I dropped it into a clutch specialist, had the clutch replaced and after picking up it on my drive home the pressure went again.

Gear changes seems fine(goes into gear easy, no grinding etc) with or without pedal pressure.

I've checked the slave cylinder, no visible leaks. Had a friend press the pedal while I was under the car and slave is operating.

Can't find any visible leaks around the master cylinder (fluid level may have potetlntially dropped a little, its under the max mark but I'm an idiot and didn't check it until i had problems) or anywhere on the lines.

So I'll be honest, I'm pretty mechanically inept but my thoughts is if it was the slave i would of expected a leak underneath the car and the reservoir empty. If it was the booster I thought I would be be having the opposite syptoms (clutch much harder to press?) which leads me to the master. But I'm at a loss because the clutch seems to be engaging and gear changes are fine even with no pressure.

Im going to order a new slave and master today and have a go at fitting them myself.

If it fixes the issue will update this post.

In the meantine, anyone had any similar issues?or even if my line of thinking somewhat makes sense? I'm at a total loss.

Thanks, J

[mudski]

The clutch fork does bend and break on the odd occasion in Patrols. Also the pivot ball the fork rests on snaps off. Failing those, you probably have air in the system. Or the hose has gone soft and bellowing out when the clutch is depressed.

[mudnut]

The clutch "specialist" should have dealt with all the issues when replacing the clutch.

[mudski]

The clutch "specialist" should have dealt with all the issues when replacing the clutch.

In an ideal world...

[mudnut]

Not really. If he replaced the most expensive piece of the system ( clutch) because of the problem, and the problem is still there then the 'Specialist' should fix it.

Sounds as if he was out for easy money.

[BrazilianY60]

I could get it back by pumping the pedal a few times but pressure would go again after a few seconds.

To me, this indicates Master Cylinder.

[mudski]

Not really. If he replaced the most expensive piece of the system ( clutch) because of the problem, and the problem is still there then the 'Specialist' should fix it.

Sounds as if he was out for easy money.

Sounds like that to me aswell.

Should is the key word there Craig. People that work in all trades should do many things, but as I've experienced over the last 18 months, they never do. You always have to finish the work yourself. Trust no one.

As for the OP's issue. I think maybe just air in the system.

[Deano2506]

I'd be looking at master cyl.
Internal seal is probably gone allowing fluid to leak back into reservoir with no external leaks

[JDM22]

Thanks for the replies everyone. In fairness to the specialist he asvised me he was booked out for a month. I explained my situation and he booked me in for the following week.

So I tried bleeding went through 2 bottles of fluid and still the same(although searching the forums the GQs are apprently notorious for being a ***** to bleed) Slave and master cylinder ordered. When they arrive ill give it another go and give an update.

Appreciate the help!
J

[Tip12345]

slave cylinder gets hot from the exhaust and goes awol !

[MudRunnerTD]

I reckon it is a Vac issue. So it feels Normal with some feedback most of the time and super lite zero feedback pedal that lifts back off the floor though by itself? Not a zero feedback pedal that stays on the floor?

If it lifts back automatically And regardless of the pedal feel the Clutch functions? Then I think it is Vacuum related and not a system fault. Does it ever happen at first gear at a stand still and the clutch still works? If so then I would say 100% Not a Master or Slave fault. Zero Vacuum would make the peddle like a Brick and nearlly impossible to push down (try pushing the clutch in with the engine off, that is zero vacuum) I think it is important to determine if it happens while stationary at the lights. It is easy to change gears without a clutch at all through the rev range but NOT while stationary.

[JDM22]

OK here I go again, I've tried replying to this thread multiple times but my reply isn't showing up.

I replaced the master and slave cylinder and still got the same results.

I ordered a handheld bleed pump and bled the lines using the pump from each bleed nipple(passenger side bonnet and on the slave cylinder) starting with the slave.

I'd do this once until I couldn't see anymore air coming out, pump the pedal and until I had good pressure, left it for 15 mins and if the pedal went soft after 15 mins I'd do the process again. Took around 5 tries until the pedal stopped going soft.

Been going almost a year now with no issues.

[MudRunnerTD]

Thanks for the follow-up mate. It helps others when searching for answers when the thread is finalised. Cheers.