Bj40 Brake problems..

[Scobby12]

Hi all,
Im having trouble with my brakes... i found that two pots on my front calerper where sized so i free them up, after bleeding brakes all round the pedal still goes to the floor but after one pump it holds pressure and does not lose it i found this thing under the i would like to know if anyone knows what is master cylinder and i would like to know if anyone knows what is.

also what could be the problem iv adjusted the back brakes and all but still goes to the floor it has disk brakes in front and drums at rear any help will be appreciated.

[Scobby12]

Also there is a little clang when i put the brakes on while driving


Any ideas?

[leeogrady]

Hi mate,

bit of a long shot, but my mates hilux had this issue. Check the wheel bearings.. my mate destroyed the outer one on one wheel completely (when replacing there was nothing left that looked like a bearing )
basically the disk was able to tilt enough to spread the calipers hence the first pedal push to the floor and the second push got contact.
good luck.

cheers

[Smurf]

Hi mate,

bit of a long shot, but my mates hilux had this issue. Check the wheel bearings.. my mate destroyed the outer one on one wheel completely (when replacing there was nothing left that looked like a bearing )
basically the disk was able to tilt enough to spread the calipers hence the first pedal push to the floor and the second push got contact.
good luck.

cheers

I had the exact same problem on my Prado when I got it. The disc had eaten into the caliper

[Scobby12]

Hi mate,

bit of a long shot, but my mates hilux had this issue. Check the wheel bearings.. my mate destroyed the outer one on one wheel completely (when replacing there was nothing left that looked like a bearing )
basically the disk was able to tilt enough to spread the calipers hence the first pedal push to the floor and the second push got contact.
good luck.

cheers

Im aware of this cause but iv replaced the bearings thats how i figured out the brake pistons were sized then problems showing up

[Scobby12]

im starting to think it may be the master cylinder or that thing if its some sort off valve?

[leeogrady]

if the seals go in your master cylinder you could get a similar result i guess..
I think the 'clang' you hear is likely telling you something. I would double check everything under there for something loose, have you checked the rear brake system?

[ClassicCruiserSpares]

That thing your pointing to is a proportioning valve splits braking between front and rear so fronts work more than the rears. Sounds like you need to bleed all the brakes better, front and rears.

[Scobby12]

if the seals go in your master cylinder you could get a similar result i guess..
I think the 'clang' you hear is likely telling you something. I would double check everything under there for something loose, have you checked the rear brake system?

Yep adjusted and all

[Scobby12]

That thing your pointing to is a proportioning valve splits braking between front and rear so fronts work more than the rears. Sounds like you need to bleed all the brakes better, front and rears.

Thats what i thought it was but it looks like only the one pipe for the rear brakes go into it.. that lead me to think its not..iv bleed the brakes quite a lot and no air coming out, should i just keep trying?

[Scobby12]

Any other ideas?

[niblik]

so you have discs up front and std cruiser 40 drum rears?

whats your front calipers out of?

if still drum rear, adjust up oober.. pump brakes.. do again.. and again...








and again....

where abouts in kiwiville do ya reside dude?

[Scobby12]

Its got orgianal brakes all round disc at front drum in the rear


And im in nelson Mate thanks for your help will have to try it out

[handydog]

try and isolate if the problem is coming from the front or rear brakes... Clamp the rubber hose going to the to the rear brakes above the rear diff; this will give you an indication of which end to work from. If it cures the peddle problem then try clamping the rear wheels one at a time to isolate which side. good luck

[churchill]

That thing your pointing too could be the residual pressure valve. What it does is hold a little pressure in the rear drum cylinders so that the shoes don't have to travel all the way each time you press the brake pedal. This failing might cause the symptoms you are talking about.

[Scobby12]

try and isolate if the problem is coming from the front or rear brakes... Clamp the rubber hose going to the to the rear brakes above the rear diff; this will give you an indication of which end to work from. If it cures the peddle problem then try clamping the rear wheels one at a time to isolate which side. good luck

Thank you will give that a try!

[Scobby12]

That thing your pointing too could be the residual pressure valve. What it does is hold a little pressure in the rear drum cylinders so that the shoes don't have to travel all the way each time you press the brake pedal. This failing might cause the symptoms you are talking about.

Interesting... is there anyway i could pull it apart?

[churchill]

There must be a way to get it apart, never pulled one apart myself but will have to soon as I'm doing a disc conversion and they need to come out for that.

[niblik]

As jason aka classiccruiserspares has said, pretty sure it's a proportioning valve.

There must be a way to get it apart, never pulled one apart myself but will have to soon as I'm doing a disc conversion and they need to come out for that.

I've done a rear disc conversion. mine is running the stock proportioning valve and it all works a treat.

[niblik]

try and isolate if the problem is coming from the front or rear brakes... Clamp the rubber hose going to the to the rear brakes above the rear diff

Careful if you want to try this method as the aged rubber hosing can get damaged causing a leak and force replacement of flexy line.

[Scobby12]

As jason aka classiccruiserspares has said, pretty sure it's a proportioning valve.

There must be a way to get it apart, never pulled one apart myself but will have to soon as I'm doing a disc conversion and they need to come out for that.

I've done a rear disc conversion. mine is running the stock proportioning valve and it all works a treat.

But the reason i think its not is because only the back brakes are hooked up to this valve, if it is a proportioning valveshouldnt the front brakes be hooked up as well??

[niblik]

couldnt see much detail in pic sorry chap..

could it act as a restrictor similar to the willwood adjustable style valves, so it is effectively letting through less fluid to the rears so thus sends more fluid forward.. hence portioning the fluid?

[ClassicCruiserSpares]

If it is a proportioning valveshouldnt the front brakes be hooked up as well??

Nope! all the proportioning valve does is reduce the braking on the rear so the rear dont lock up before the fronts, This will allow the front to dive under brakes.
Your wasting your time with the proportioning valve thats not your problem, Could be a few things, rears not adjusted properly (most people dont know how to adjust shoes properly), not bleed properly, maybe a master cylinder or booster problem or all of the above

[Scobby12]

If it is a proportioning valveshouldnt the front brakes be hooked up as well??

Nope! all the proportioning valve does is reduce the braking on the rear so the rear dont lock up before the fronts, This will allow the front to dive under brakes.
Your wasting your time with the proportioning valve thats not your problem, Could be a few things, rears not adjusted properly (most people dont know how to adjust shoes properly), not bleed properly, maybe a master cylinder or booster problem or all of the above

Ok will have to make a list lol i will bleed them again and adjust the brakes (is there a particular way to do it?) i was thinking of getting a rebuild kit for the master cylinder but ill try the other ways first

[ClassicCruiserSpares]

De adjust your handbrake rite off, adjust ya rear shoes then bleed last.

[Scobby12]

De adjust your handbrake rite off, adjust ya rear shoes then bleed last.

ok sorry if im being a dumb ass but the hand brake seems to hold the drive shaft not working on the drums

[ClassicCruiserSpares]

De adjust your handbrake rite off, adjust ya rear shoes then bleed last.

ok sorry if im being a dumb ass but the hand brake seems to hold the drive shaft not working on the drums

Nah your all good, forget the handbrake bit then yours must be pre 1980 if you got the handbrake on the rear of the gearbox.

[Scobby12]

De adjust your handbrake rite off, adjust ya rear shoes then bleed last.

ok sorry if im being a dumb ass but the hand brake seems to hold the drive shaft not working on the drums

Nah your all good, forget the handbrake bit then yours must be pre 1980 if you got the handbrake on the rear of the gearbox.

rego says 1980 lol maybe older drive train? as the engine was replace by old owner lol

[Scobby12]

Hi all,
My brakes are now fixed.

Pulled my right hand drum apart to find one of the pistons where jammed
So i pull it apart give it a clean up resembled put the drum back on bleed the brakes and adjusted now they are back to how they where

[niblik]

an easy win.. sweet!