40/60 BRAKES

[Shorty40]

Working on the 40 on the weekend. I say 40 but for this question it has 60 series diffs. Drum rear and disk brake fronts

Pulled the rear drums apart gave them a good clean out and then adjusted them. All seemed to go well.

Moved to the front where I had a new master cylinder to put in. Got it in no worries. Bled the brakes up until I had no bubbles and nice clean fluid pumping out. All good. Nice firm pedal again.

I noticed though on the test run that the pedal was good but the braking resistance wasnt so flash. Almost like the pads were glazed (but they arent). Good pedal but not the best brakes - maybe I adjusted the rears incorrectly

What have I done wrong or what did I miss ?

[planb]

What have I done wrong or what did I miss ?

i think you're forgetting that you have drum brakes and 38s, are you running a booster ?

i fitted a brake booster from an 80s into a mates 40s cruiser with 38s and it locked up real good (it had drums in the rear)

[Shorty40]

Yeah I have a booster

The 38s aren't the issue as it braked pretty hard before the weekend 'tinker'. Its just that the pedal would fade to the floor and always need a pump to bring em up again. Thats why I 'fixed' them on the weekend

But now it brakes worse than when I 'fixed' them

[MY45]

Yeah I have a booster

The 38s aren't the issue as it braked pretty hard before the weekend 'tinker'. Its just that the pedal would fade to the floor and always need a pump to bring em up again. Thats why I 'fixed' them on the weekend

But now it brakes worse than when I 'fixed' them

Dan it sounds like the booster isnt working or connected quite right.....I have an 80s master cyclinder I can lock up the 37's no worries.

[planb]

you could always fit a booster out of an international scout, from memory

they are about 4ft long and will lock up a semi trailer, let alone your pansy heap

but if the pedal isnt fading, i would just adjust the drums again and bleed the system again (how are you bleeding anyhow ?, is your son helping you out) you know you shouldnt depress the brake pedal all the way to the floor, but about 1.5in off the floor,

[J Top]

Put your foot on the brake and start the motor,does the pedal go down?
If the pedal goes down a bit the booster is working.
Is the master the same size bore as the one you took off. If the bore is larger you have lost your leverage ratio.
J Top

[Shorty40]

I will try the foot on brake and start thingy tomorrow

Master cylinder is identical to the one i took off (apart from being new )

Apparently there is a hose from the booster to the alt ??? Anyone ?

[GeneralFubashi]

hose can go to alt, but usually has a steel vacuum canister somewhere in line. On the Bj40 its under the passenger side footwell, some Hjs have a small can type thing on the firewall. Petrols get their vacuum from the intake manifold with no canister.

[Shorty40]

That would be cool if it was standard 40 series stuff. But it is 60 series diffs and brakes with an unknown booster with a 253 holden v8.

Its a bitsa Makes it hard to get everything

[Shadow]

HJ60 series gets vacum from vacum canister (round black thing attached to passengers side firewall), the canister os connected to the vacum pump which is on the back of the altenator.

youve got a petrol so i doubt if your altenator will have a vacum pump on the back of it, which means youl have to take vacum from the intake manifold as suggested by GeneralFubashi.

[skootin]

60 ser brakes have a self adjuster which operates off the handbrake
ie when you pull the handbrake on it adjust the shoes.
Just because the mastercyl looks the same doesn't mean it works the same inside.You should have a master cyl off a BJ42/FJ4010/82 on they had disc brake frt and drum rear.Looking brakes is not really a good thing for stopping.

[Shorty40]

60 ser brakes have a self adjuster which operates off the handbrake
ie when you pull the handbrake on it adjust the shoes.
Just because the mastercyl looks the same doesn't mean it works the same inside.You should have a master cyl off a BJ42/FJ4010/82 on they had disc brake frt and drum rear.Looking brakes is not really a good thing for stopping.

Its all about the 'bitsa' again

I dont have a rear handbrake - so its a bit hard to 'self adjust' I have a custom made transfer case disk brake

The master cylinder is the same one as the one I took off. Same model number.

I thought, as others have suggested, that the booster may be in need of replacing. But it worked 10 minutes prior to my 'tinkering'.

Possibilities:

a. I bled the brakes incorrectly
b. The master cylinder wasn't bled correctly
c. The rear drums were not adjusted correctly

[skootin]

GO with option B
Then do option C
the self adjuster bit takes care of the adjustment as the pads wear down but the wheel cyl and manual adjuster do all the work.