24 replies to this topic

[slidehammer]

That would be a single circuit master cylinder, so to me that indicates that is fine as it is working on the front brakes fine. What about cracking the pipe to the bias valve and see if fluid is pumping to it, then tighten and try the pipe on the brake side of the valve and see if no fluid is present there, that would pin point the valve as being the issue.

Edited by slidehammer, 03 August 2024 - 09:46 AM.

[Spider]

Given the age of it and it appears little done in between drinks, I'd be quite certain the Pressure Shut Off Valve on the rear subframe is rusted closed.

Crack the tube nut on the Inlet to this and see if you get fluid there, then try one of the outlets.

[absx2]

I`m guessing you have new flexi hoses because the old ones collapse and swell and you won`t get fluid through them.

 

If the car has been standing it`s new cylinders and hoses all round by default and don`t forget the clutch slave cylinder that will quickly let you down after a few miles. 

 

Edit

Crikey, I have re-read the post ( 30 years ) so I`d be replacing both master cylinders as well as everything else

Edited by absx2, 03 August 2024 - 11:49 AM.

[bpirie1000]

What kind of master cylinder have you got?

Also start at the start of the rear pipework and crack each join and test until you find where the issue is..

Could also try a gunsons bleed kit. Takes pressure from a spare wheel and pushes the brake fluid through the system..

Also how old is the brake fluid. Could be a contaminant in there certainly think the bias would be the issues though..

Try checking each join.......

[Ethel]

Ethel, the vacuum pump has a gauge that showed a vacuum was being created. Once the vacuum is created the bleed valve is opened. The vacuum then disapates. But no fluid is drawn.

The process went well on the front brakes

 

 

You are likely to get some air leaking in by the thread on the bleed screw, but that would be constant whether or not it's closed. If you suspect the valve, opening the other rear bleed screw would allow you to suck air through, proving the pipework down stream of the valve is good. Along with the suggestion to bleed at the valve's inlet would pretty much confirm the valve is blocked.

[icrocky]

Hi All

 

Thank you for all your help. Replacing the regulator valve has solved the issue and the brakes are bled and working well.

 

However, given how long the car was off the road, I am going to replace the flexible hoses, wheel cylinders (although no sign of weeping) and the master cylinder.

 

Fortunately I don't have clutch hydraulics to worry about as the car is an automatic.

 

Once again thanks for all the valuable input

[bpirie1000]

All part of the service.. now go get many smiles per mile....

Also consider spending a fiver as a thanks to everyone. Keeps the forum going......

Cheers..

[icrocky]

Thanks, can you tell me where on the site I can make a contribution please?

[Quinlan minor]

Thanks, can you tell me where on the site I can make a contribution please?

https://www.theminif...at-mini-spares/

 

The TMF+ Membership wil give you a 7.5% Discount on parts from Mini Spares.

Read the link on how?

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Edited by Quinlan minor, 05 August 2024 - 10:29 AM.

[icrocky]

Brilliant, thanks very much. I have paid for the subscription