BJ74 Vacuum issues, No vac to clutch

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Mar 11, 2007
G'day All,

Did a search and couldnt find anyone with an issue like mine, most seem to be a faulty booster or vac leaks.

My vac booster never worked, press it in, cover the port and let it out and no suction. Put in a new booster, no difference at all. Pulled the vac lines to the booster and there is no vacuum.

Brakes have vacuum at the booster. Pulled both the lines off at the pump, which leaves me with two barbs, the brake vac line pulls enough vacuum to suck my finger into the tube, the clutch booster vac line has NOTHING. They look like they both come from the same block on the pump, so what gives? Could there me a blockage or is there something inside the block? The manuals I have were not very helpful.

When everything was stock with VAC transfer case everything work (except had a heavy clutch) 4x4 worked, brakes have vac, engine swtich off fine.

Any ideas?
Fixed! But found a new problem.

Booster was abit iffy, check valve was stuck and the vac line between reservoir and booster was holed, PO had stuck a bolt in it to close it off.

New problem, vac pump doesnt seem to have much suck. Everything is fixed now and I have the clutch and brake boosters holding vacuum, but there doesnt seem to be much. Need to get my hands on a vac guage and check it.
Not sure if this will help but have you checked the vac canister for the clutch. The brakes and clutch have a seperate canister that the vac lines run to from the pump. So it's vac pump then vac can then onto the clutch booster. Not sure if there is a valve or something on the vac canister but it might be worth checking if it's busted or has a hole in it or something. Can remember where I read it but I have heard of them rusting out.
This thread will become irrelevant soon. Was trying to figure out how to measure the vacuum, found a old boost guage, hooked it up to the small port on the vac pump with the brakes and clutch still hooked up. Got 25 in/HG vac and the clutch was as light as a feather! Never had a cruiser with this much vacuum cant wait till I test the brakes out!!

Looks like there is a leak "somewhere" after the vac pump in the millions of small vac lines and solenoids. Going to buy 10m of vac line and replace the lot and try to isolate some parts.

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