BJ74 won't turn off

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LowFour

LowFour

10 Year 15 Year 20 Year
Joined
Jun 13, 2005
Threads
16
Messages
76
Location
Borroloola, Australia
I posted about this problem a while ago (https://forum.ih8mud.com/showthread.php?t=57856), the consensus then was a dodgy VSV. I haven't done anything about it, but rang a couple of mechanics when I was in Darwin last week. They sounded pretty clueless, it sounded like the job was going to be an expensive fishing trip.

Since then I've done a bit of looking around on the net, found out that if the brakes or clutch are also dodgy (mine are, especially clutch), there might be problems with the vacuum system. One guy wrote that his clutch booster seal had failed, and with each clutch application he was pumping fluid into the vacuum system, which affected the brakes and the vacuum shut off.

Anyone got any ideas about this? It's a twenty year old truck, so it's no great surprise if these sort of seals start to go. I took it to a brake and clutch place in Darwin, who said the clutch master cylinder needed resleeving - no replacement available in Oz. But maybe the problem is more with the booster circuit, as the clutch (and the shut-off) work fine on short trips, it's only when the engine's been running for a half hour or so, in build-up weather, that things start going weird.

Peter
 
That's weird! No replacement in aussie???

The guy is yalking s***, any clutch master cylinder, from a HJ60/61/BJ7* from that period with clutch booster should work. There's several things which can go wrong in the vacuum circuit. The pump at the end of the alternator is often one. As for shuting off the part 22419 is a lever which gonna stop the engine. If it's not this one, there should be one looking right this one, on the injection pump, which should stop the engine.

moteur13BT35.gif
 
I found that lever after a few heavy-duty stalls. It's annoying though if you've got a few errands around town, after the engine's warm, and you have to pull the bonnet to stop it every time. The clutch is probably more of a nuisance though, my left leg is getting twice the size of the right. Because the non-stop and the hard clutch happen at the same time, that has got me thinking about all this vacuum bizness.
 
before i ordered the booster i would check the amount of vacumm coming out of the pump and follow all the vacumm lines to make sure none are cracked or came loose...
 
hit the gas to turn off

I have the same problem with shutting down and clutch stiffness. I figure it is a vacum leak. Giving the throtle a shot is enough for mine to shut down. It dose not happen often enough for me to find the leak yet.
 
Remove the hoses from the brake and the cluch boosters, plug them off with a bolt, start the motor and if everthing else works, then its in the boosters, fit one hose back on then retry it.
Process of trying each part till you find the leak.
A friend had this problem, turned out to be the clutch booster seal.
 
The VSV is in a bad position on the 13B-T...it's prone to getting wet when doing deep water fording or washing your engine. Sheldon and Greg pointed this out to me, and I found out for myself when my BJ74 wouldn't shut off one day after being washed. You get that VSV wet often enough and it will eventually kick the bucket.

Buy yourself some vacuum hoses to extend the ones on the VSV and relocate it to a moe logical spot.
 
Same on a local truck, clutch booster.

How about putting a vacume line inside the truck from the VSV and whenyou want to shut it down, pop it in your mouth and suck air like the devil......


LOLOL

Gotta have some fun around here once and awhile...
 
Just buy a vacuum gauge and tee it in. See what it pulls. You probably have a leak in the system. Look for obvious stuff on the lines first. Like a crack or a loose end.

Trace the lines from the Alt. If your vacuum is weak, your engine won't shut down, brakes will be hard, clutch heavy. Possible 4x4 won't engage if you have vacuum in that..........

My Mercedes diesel is covered in vacuum lines. Vacuum door locks,etc... the whole thing uses vacuum. Even the heating system in depth...
 
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