I developed a problem with my clutch where I'm hearing an air leak upon releasing the clutch peddle. The clutch peddle has intermittent levels of resistance during those times. I have determined the air leak sound is not coming from inside the cabin but rather from somewhere in the engine bay. This leaves me to believe there's a leak within the lines going/coming from the booster within the cabin (through the bulkhead) to the clutch vacuum-assist reservoir or the reservoir itself. The FSM isn't very helpful in this area and I was wondering if anyone has had to deal with a similar issue. Also, anyone having pics illustrating those vacuum lines to/from the reservoir and what the actual reservoir looks like would be very helpfull.
Thanks Raheen, but I wasn't looking to create more work for myself and rip out perfectly working components just because I can. I have a Z1 heavy duty 6 puck clutch and my research shows that deleting the vacuum assist part and/or switching to an NA set-up creates an even stiffer clutch peddle performance. It would be a step in the wrong direction. Do you have pics of you deleting these components? At least it would give me an idea of what I'm facing. Specifically, the two vacuum assist tanks - one round and one square? And how and where they're mounted?
The tanks are in the drivers side fender. The most effective thing you can do would he carry out a smoke test to confirm and locate the leak. The booster system consists of the two tanks, a few feet of hose and the booster itself. Not hard to replace the faulty component if there is one.
In the short term to allow you to diagnose whether the booster is leaking or if its the engine bay associated parts. Run a hose directly from the booster to the engine. Insert a brake booster one way valve in on this line and see what occurs. Doing this will temporarily delete any of the reservoirs that are usually in the vac circuit. And hopefully fix the problem. If not, well then it looks booster related. Iirc correctly, your zed is a JDM RHD model. If you run the hose from the booster, across the firewall and into the taped hose fitting in the plenum on the LHS of the engine. The hose length will be more then adequate in volume for the booster to work properly. I run ours like this 100% of the time. As our zeds an auto converted to manual, using TT parts. Ive driven many times now with this setup, and never have i came short in loosing vac boost assistance. Which we like as we have a HD TT clutch assy and without the booster, its a bit too much effort. Brake cylinder one way valve i just got from a brake shop. Cost $10. Length of suitable vac hose $10. Cheap and easy. See what happens.
Thanks for that Sanouske. It does sound rather complex what you're proposing. To my understanding, the clutch booster is attached to the end of the clutch peddle inside the cabin so running a secondary line from that may be difficult to route through the firewall. Can you post pics that illustrates this?
Thank you Rob. This is a step in the right direction. 1. I take it that it's necessary to remove both the fender liner and the fender itself to get at the 2 vacuum tanks? 2. Where would be the best place to introduce the smoke from? I have found a pic that's helping me understand the layout of the clutch vacuum system. However, I believe it's based on the LHD config. I'm curious if there's a similar diagram (perhaps in the FAST program) that shows the same thing for a RHD? Anyone having actual pics of this would be greatly appreciated.
From memory you can just find the vacuum hose that's on the clutch booster and connect it straight to the hose that comes of the balance tube/manifold with the one way valve still in place and this eliminates the booster tanks and associated hose. A quick way to see if the problem lies in the booster or the tank / line side of things. Clutch booster will still work you just won't have the reserve for long clutch use. Cheers Dave
Thanks for that Dave. At present, it's my intention to retain the oem config for now. If there's someone who could post pics of the vacuum tanks it would help a lot.
If you can hear a leak during movement of the pedal but no other time (should be able to hear it with engine off for a couple of cycles) then you have a leaking booster, remove and replace. If it were any of the hoses or the tanks then it would leak all the time and would not hold any vacuum when you shut the engine off.
That makes sense Glenn. However, I am not hearing any of that leaking sound from within the cabin. With the aid of a friend, we do hear it coming from the engine bay when we activate the clutch pedal. Now it's quite possible it's leaking all of the time from one of the hoses or tanks but that sound is concealed by the engine noise. But when the clutch pedal is activated while the car is running, that sound may be accentuated enough so that it is audible enough over the engine noise. Is that not possible?
Is the vacuum line coming from the end of the balance tube the one that supplies the vacuum feed to the two clutch vacuum tanks?
Turn the car off & leave it for a few minutes, pull the line off the clutch booster, if it sucks in a heap of air then there are no (significant) leaks while the booster is stationary. Hook the hose up again, run the engine for a few seconds to replenish the vacuum in the system, shut the engine off & then move the pedal if you can hear a leaking noise change the booster & give yourself a pat on the back. Don't be fooled by the normal amount of noise the system will make SOME noise is 100% normal, a lot of noise is not. Those boosters are poo IMO, my wife drives a TT with a six puck clutch & NA clutch gear no problem at all - mind you she is a Kiwi
