Clutch vaccuum loss

[Stoknisan]

After having a play on the weekend I found that i was loosing clutch stroke on the way out of the bush. it got so bad by the time I limped home I had only about 1/4 of the clutch pedal stroke left. The engine seemed to be surging between 2200 and 3500 revs. I have been told that it is a vaccuum problem some where.

Has any body had this problem before? I should mention that my truck is a 93 GQ LWB TB42 and I had a new safari heavy duty clutch installed about 5000 kms ago.

Thanks in anticpiation

[BowTieGQ]

I had the same prob not long ago. Crap idle, running rough and flat spots. I could hear an air leak near carb but couldn't locate. I tracked it down to the clutch booster. If you remove the master cylinder you will see a small, about 1", seal. It was that one that was leaking. As I was too scared to ask Nissan a price, I rang everywhere to no avail. Back to Nissan again. You wouldn't believe the price! About $15 for the whole rebuild kit! Even has the lubricant in the kit.

[Stoknisan]

Thanks for that,

Now you mention it at one stage I thought I could here a leak around the booster, I'll give it a go

[Stoknisan]

Thanks for that,

Now you mention it at one stage I thought I could here a leak around the booster, I'll give it a go

[Stoknisan]

Thanks for that,

Now you mention it at one stage I thought I could here a leak around the booster, I'll give it a go

[holeyhardtop]

i searched and this is the closest response to my current problem. my gq diesel clutch today decided to go hard when depressing it whilst driving down the road. i have checked things out and the booster is getting vacuum, there is no leaks from the hydraulic side of the system and everything works ok it's just got suddenly heavy but occasionally goes back to normal for a moment or two.

nissan quoted $16 for a rebuild kit for the clutch booster which is nice and cheap. my query is, is it a hard job to remove the booster and replace the diaphragm etc. in the booster? and can i disconnect the hydraulic cylinder from the booster without having to bleed the clutch again{it looks possibleif i undo the bolt 'with white arrow' and the one directly under it see pic}. or should i give it to the mechanic and if so approx cost?

thanks in advance
dave

[bazzle]

Also some petrol ones dont always make enough vac for any reserve. Fix is to add a small aux vac tank 'T' off vac line past 1st one way valve.

Bazzle

[BowTieGQ]

Easy to get off. Bolts from inside firewall too. Be very carefull when moving master cyl out of way so you don't kink pipe. It will go though. There is a special tool to undo booster but if you are careful you can carefully pry tabs away enough to twist apart. Once open, lay parts in order they go, on bench. Put new ones in their place and reassemble. And what the hell, bleed master cyl anyway.

[BowTieGQ]

Easy to get off. Bolts from inside firewall too. Be very carefull when moving master cyl out of way so you don't kink pipe. It will go though. There is a special tool to undo booster but if you are careful you can carefully pry tabs away enough to twist apart. Once open, lay parts in order they go, on bench. Put new ones in their place and reassemble. And what the hell, bleed master cyl anyway.

[Bingham]

i have had nothing but trouble from my clutch on 89 gq.....

when working hard it looses something and no one can put their finger on it was actually blowing the lid of at one point......

[holeyhardtop]

thanks for the master cylinder tip bowtie. the bolts on the inside all look easy to access so hopefully it will be plain sailing . careful i will be as nissan quoted $841 for a new booster . this may be a silly question but i take it there is no spring in the booster? having never opened one up before i assume it will not pop open losing bits?
i will attack it when i get a weekend free very soon and take pics as i go but will put up with it in the short term but it will make it hard for the wife to drive if she needs to.

[Stoknisan]

For those who are interested i had mine checked out and it had nothing to do with the booster in the end. The viscous coupling and bearings were shagged so it wasn't creating enough vaccum, $ 400 later and all is good

[bazzle]

What viscous coupling and bearing

Bazzle

[Stoknisan]

The one at that is attached to the fan blades behind the radiator, the fan was shagged as well

[bazzle]

How did that affect vacumn

Bazzle

[holeyhardtop]

For those who are interested i had mine checked out and it had nothing to do with the booster in the end. The viscous coupling and bearings were shagged so it wasn't creating enough vaccum, $ 400 later and all is good

.[/quote]The one at that is attached to the fan blades behind the radiator, the fan was shagged as well [/quote]

i am also confused as to what you are getting at? more info please.

[BowTieGQ]

I'm not sure, but I think Berwick Nissan may have quoted me stuff all ($80ish? maybe) for a new booster. I didn't care at the time as $15 and a job I can do was enough for me. Yes there is a spring inside, but it wont go twang, bounce off the ceiling and dissapear under the bench somewhere.

[bazzle]

I cant see how the viscous fan coupling affected your vaccumn, clutch operation or idle speed..

Bazzle

[holeyhardtop]

ta bowtie, i feel more at ease about ripping it apart now ta for the advice.