Hey all
I have just replaced all the wheel cylinders and the master cylinder and now my rears lock up for about 10sec or so when i apply the brake.

i had a search and found that it could be the bias valve, is there any other reason/s why this could be happening before i go searching for a new/recon bias valve?

cheers James

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'75 windowless van
~LOLA~

Did you fit the right size rear wheel cylinders?

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David L


My greatest fear in life is that when I die my wife will sell my Mini and tools for the price I told her I paid for them!

fitted 3/4 on the rears and 15/16 on the fronts..
hope they are right - didn't know there was differnt sizes

_________________
'75 windowless van
~LOLA~

Somewhere Matt Read did a How To on turning the bias valve on the rear subframe into an adjustable one - Matt?????

Here is one way- think Matt did it different -

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David L


My greatest fear in life is that when I die my wife will sell my Mini and tools for the price I told her I paid for them!

I had the same problem. Fitted a new bias valve with no change.
Then fitted new rear shoes and drums and the problem went away.
I suspect the rear brake shoes were not the correct size for the drums, although the adjustment was OK. Are your rear shoes on the correct way around?

i'm pretty sure i didn't have to remove the shoes on the rears to fit the new cylinders but heres a pic any way..


james

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'75 windowless van
~LOLA~

Why did you replace the rear wheel cylinders? If it was because the wheel cylinders were leaking, brake fluid on brake shoes make them more sticky and they lock when the brakes are applied.

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"In two years time your car will be like a lady's clothes, out of date, my car will still be in fashion when I am dead" - Sir Alec speaking to Pininfarina

hey, good one Rob - glad you got that problem sorted

monkey, what do you mean by this bit?

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did I tell you that I won a trophy?

1018cc,
yeh i replaced them b'cos they were shot - no fluid was leaking but when i pulled the rubber back on the old cylinders there was a lot of rusty fluid that came out.. i'll give them a clean with some brake cleaner and see how they go.

simon,
when the car is up on stands n i apply the brakes then release them n try to turn the rear wheels by hand they will not budge, fronts are fine.
and i dont have the hand brake on
i also went for a test just up and down my drive way and after stopping then going agen its like the hand brake is on (rears wont rotate, just skid/slide) for a second or two then everything is normal untill i brake agen...


hope all of that makes sense

_________________
'75 windowless van
~LOLA~

sounds like they are sticky... maybe bleed the lines and see how you go?

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78 Leyland Mini - Prince

It could also be the flexible hoses cause if they are original they can collapse internally.

So to explain the prop pressure is applied pushed past the blockage and then takes several seconds to release pressure form the wheel cylinders.

Or
As others have said it could be the pressure regulator up the back.

Cheers
Matthew

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You don't buy an Austin....You invest in one!!!!

Proud Owner of a 1971 Austin 1300 GT

thanks guys i'll check out those things today.
is there anyway of checking to see if it is the bias valve? or is it just a matter of elimination and replacing it n hoping its the problem

_________________
'75 windowless van
~LOLA~

the fact that it's both wheels kinda points to the prop valve - I'd pull it apart and clean it out -

have you flushed the system - IE let all the fluid out, run half a litre of metho through it, and then fresh brake fluid - if there is a lot of gunk (rust, slime etc.) then things may be getting blocked

_________________
did I tell you that I won a trophy?

Photo shows right assembly for right side drum - is the left side the mirror image?

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David L


My greatest fear in life is that when I die my wife will sell my Mini and tools for the price I told her I paid for them!

it's a fluid return problem....

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did I tell you that I won a trophy?