Vacuum System Problem

[boogie74]

Hi All,

I need to ask the cruiser gurus' a question about the Vac System!!
I have a BJ74 so you know what model I'm talking about.

I have had an intermittent problem with the Cruiser for some time now. Symptoms have been the engine not turning off and a stiff clutch. Then more recently the brake pedal has been hard and 4WD is now not engaging. First I thought the vacuum tubing might be the prob. Replaced it and no joy. Then I suspected the vac pump that runs off the back of the alternator (I hope its not this!!).

Today when i was staring under the bonnet and contemplating life and vac systems i noticed that the brake master is oozing fluid. I've noticed that the brake fluid level has been ever so slowly dropping since I've had the cruiser (18 months). I have been topping it up every few months. Soooooo... I have come to the conclusion that the brake system is leaking/cuctus....duh. If the brake system is leaking fluid i spose it would also leak air/vacuum. So it is my hope that if I replace the brake master and booster all my other problems will be solved.

Have any mudders had any experience or have info on this problem? I'm going to replace the master and booster anyway but if I could get some opinions on the problem and any fixes that would be awesome and I would be eternally gratefull.

Cheers,

Gav.


please discuss......

 

[oldblue]

Look at removeing the boster and replacing the seal that is on the firewall side, a common problem.

 

[boogie74]

Thanks Old Blue,

That would be the body seal that sits right behind the master cylinder, about the size of a 20c piece. I'll check it out. I should check that I'm getting vacuum to the booster first. I forgot to do that. I'll keep working on it.

Thanks for the ideas.

Keep em' coming people.

Cheers Old Blue,

Gav.

 

[boogie74]

Well I've made some progress.

Just checked the vac lines to the brake and clutch. As soon as I pulled the brake vac line off I heard a whoosh!!! Ok so I have vacuum here. All good. Then I checked the clutch. No whoosh as I took of the vac line. I plugged the vac line and everything works. Engine turns off and 4wd engages. So I've found the source of the problem. Faulty clutch booster I presume.

What is the most likely fix for this? Source a new booster or rebuild? Does anyone know which seal is likely to go in the clutch booster? Just trying to narrow it down before I pull it apart. In the mean time would there be any proplem with driving around with the clutch vac line plugged so everything else works?

Cheers mudders,

Gav.

 

[boogie74]

Well I've made some progress.

Just checked the vac lines to the brake and clutch. As soon as I pulled the brake vac line off I heard a whoosh!!! Ok so I have vacuum here. All good. Then I checked the clutch. No whoosh as I took of the vac line. I plugged the vac line and everything works. Engine turns off and 4wd engages. So I've found the source of the problem. Faulty clutch booster I presume.

What is the most likely fix for this? Source a new booster or rebuild? Does anyone know which seal is likely to go in the clutch booster? Just trying to narrow it down before I pull it apart. In the mean time would there be any proplem with driving around with the clutch vac line plugged so everything else works?

Cheers mudders,

Gav.

 

[Hulsty]

I dont know if you can rebuild them, I just fitted a booster from a 60 series to mine, few small mods and it went straight in. 60 series units are much easier and cheaper to get than 70 series units

 

[boogie74]

Hi Hulsty,

Thanks for the info. There is a 73/74 cruiser that is being wrecked at a local wrecker so I'll see if I can get one off it but if its already gone I'll try the 60's booster.

I've looked at the 60's ones and they look like they will bolt up but the vac hose clamps to the opposite side to the 74 series one. What mods are needed? Does the clutch pedal to booster connection need any modification on the cabin side of things?

Sorry for all the Q's

Gav.

 

[boogie74]

Hi Mudders,

Does anyone have or know where to get a new or reco clutch booster? I've found a new one with booster and master for @ $400 AUD. Looking for something cheaper.

Cheers,

Gav.

 

[boogie74]

I love replying to my own posts as you can see......

Well I've been doing heaps of searching for the clutch booster. Called everywhere from Adelaide to Melbourne to Sydney to Brisbane. No good though. The local wreckers BJ74 was hit on the drivers side and the foot well is crushed so the clutch booster looks like it coulda been broken. I'm not gonna take any chances with it. Not at $150.

Anyway I was looking at ToyoDIY.com and the BJ74 and HZJ78/79 clutch boosters look identical. There is a slight difference in part numbers but I reckon its a perfect match.

Anyone done it/know about it/wanna agree or disagree???

Been driving around with the clutch vac plugged and the cruiser is going good but I wanna have it 100%

Cheers,

Any comments would be appreciated.

Gav.

 

[Hulsty]

The 60 series one I fitted was an ebay specifal from a HJ61, all bolted up fine, I just had to bend the vac fitting 45 degrees to work and extended the rod to the clutch pedal.