Hi lewy.
Yes the booster is okay, the vacuum escapes.
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Haven't cracked the diaphram in the booster by any chance? This would have a similar effect to removing the vac hose. With the engine running, are there any sounds of leaking air around the booster? If you find any whistling or air leaking in that is not coming from around the hose, that could be the problem...
Hi SIImad
I am thinking that by pulling the vacuum hose off, it has allow a rush of air in, driving the master cylinder plunger in further inside the cylinder, than it normally travels and it now has stuck in. This hasn't allowed the fluid to return from the wheel cylinders back to the reservoir and has kept the shoes against the drums.
I may be cack about with the operation of that booster, but the plunger does sound like it's stuck, as the rubbers may need replacing, but it usually works out, cheaper, quicker and safer to throw the old master cylinder away and put a new one on.
Is your booster easily removed without disturbing the master cylinder? As soon as the booster is out of the way and the brakes are released, this would mean that the booster is faulty.
However, if after the booster is removed the brakes stay on, then it's the master cylinder that's crook.
Cheers Arthur
Hi again
Is your booster one of the type that is mounted on the brake pedal box?
Or is it the type that was retro fitted into the pipe work coming from the original master cylinder and mounted on a bracket on somewhere, like the side of the mudgard?
Cheers Arthur
Hi Arthur.
Will take a look tomorrow morning.
Many thanks!
AJ.
I once had my break shoes not returning after breaking after I had my booster diaphragm changed.
I found there is a small adjustment screw at the end of the plunger inside the booster which I had to adjust such that the travel would allow all the fluid to return to the master cylinder. This fixed the fault for me.
first up make sure that the VAC is reaching the booster start off by removing the vac line and the one way valve thats on it then sucking through the vavle..
if thats working reassmble it, have someone step on the brake pedal for you and crack the delivery nipple on the MC if the pedal doesnt move and fluid doesnt come out then the problem is in the MC/Booster and you need to remove the whole lot to investigate further.
The Master Cylinder was 100% stuffed! I removed the M/C and the servo worked fine , the brake pedal depressed without effort and the plunger that operates the M/C moved forward like it's supposed to do. When I replaced the M/C on the booster the same old problem came back. Looks like I'll be fitting a new M/C sometime this week.
AJ