11 replies to this topic

[S.Willson]

Hi all, I drive a Rover Mini 1999 1.3 MPI. I have recently notice that the braking has gone soft, I bled the brakes last weekend which fixed it for a day or two, bled them again and it did not fix them at all, the fluid is on the max in the reservoir.

 

The brake pedal will bypass the front brakes and hit the floor and engage the rear brakes, after pumping the brakes a couple of times the front braking will return or the pedal will drop quite low and the engage the front brakes with very little stopping power.

 

I have taken it into a mini specialist garage, they have not seen anything like it before, they've check the brakes over but cannot see anything obvious, they have suggested replacing the brake limiter and give that a try and then if that does not work then replacing the master cylinder, I will be going ahead with this, just wanted to find out whether anyone has any ideas or have experienced this before?

 

Thanks.

[cal844]

Are the nipples to the top on the front calipers? I'd say to bleed it again and see how you go. Check that the swrvo is working... Worst case scenario is you need to change the master cylinder.


To test the master cylinder you need to pump the pedal to pressure the system, hold it at pressure then start the engine, the pedal should drop an inch but the pressure should remain.

If the servo tests ok, wiggle the vacuum line fitting out of the front of the servo. Then dip the end of a cable tie into the servo. If there is fluid I'd rebuild or change the servo.

I have seen it where the FAMwtf valve goes porous

Edited by cal844, 23 May 2019 - 04:27 PM.

[richmondclassicsnorthwales]

Hi

 

Something has collapsed.

 

It could be a few items, the car is 20 years old. A good few items could have malfunctioned, brake hoses internally, the brake master, servo or pressure valve, cylinders or calipers..

 

You could probably give the whole system a bit of an overhaul, when was the last time the fluid was completely changed ? .

 

Additionally, brake lines, they are made from steel, unless these have been changed. Items corrode.

 

If you want to go one item at a time, start with looking for any leaks at the brake cylinders / calipers, front and rear. 

 

Then replace the hoses, then bleed through. Bit long winded, but this is the one step at a time method and it is a process of elimination

 

Then move onto the next, then the next, then the next. Would be better to replace a 20 year old system fully really

 

I know things cost money, but cheaper than a funeral

[S.Willson]

Thank you both, really appreciate the help. So the limiter will be replaced in the next few days so I will be able to check that off of the list, then the master cylinder and then the hoses, anything else?

The nipples are on the top on the front calipers.

There is no brake fluid leaking and as I said the fluid reservoir is at max, it seems slightly odd.

[unburntfuelinthemorning]

I think your Mini specialist has the right idea. 

[richmondclassicsnorthwales]

Brakes  components do not last l

 

I don't understand where brake parts are built for life ? What am I missing ?

 

A 20 year old system, Why do people not bother or concern them selves with old brakes, they are supposed to stop you, not kill you !

 

Money over life ??  must be a year millennium thing or some thing , not my method of thinking  -  Bon Chance !! 

[S.Willson]

Brakes  components do not last l
 
I don't understand where brake parts are built for life ? What am I missing ?
 
A 20 year old system, Why do people not bother or concern them selves with old brakes, they are supposed to stop you, not kill you !
 
Money over life ??  must be a year millennium thing or some thing , not my method of thinking  -  Bon Chance !!

I complete agree that the system is 20 years old, I'm not adverse to spending money to replacing the brake system that's why the mini is currently in the garage, just need to know what parts are needed and in what order. I am starting with the limiter because that is what has been recommended by the mini specialist.

The rear cylinders and shoes were replaced in March this year.

[Bobbins]

Had the same with my son's non-servo '86 Mini, no leaks, pedal to the floor, only providing minimal braking and then only the rear brakes. Replaced the master cylinder and all is fine.

[S.Willson]

Just incase anyone has the same issue, it was the master cylinder, once it was replaced it worked perfectly. Garage said that nothing else needed replacing.

[unburntfuelinthemorning]

Glad it's sorted.  Thanks for telling us what happened.

[Spider]

Brakes  components do not last l

 

I don't understand where brake parts are built for life ? What am I missing ?

 

A 20 year old system, Why do people not bother or concern them selves with old brakes, they are supposed to stop you, not kill you !

 

Money over life ??  must be a year millennium thing or some thing , not my method of thinking  -  Bon Chance !! 

 

The Factory and Brake Component suppliers all recommend that all Brake Rubber components be inspected and if need be replaced every 3 years / 40 000 miles.

To me, if I'm going to strip down a Master Cylinder or any other Hydraulic Component, given the low cost of the rubber seals, I'd just replace them as a matter of course while it is in bits.

 

While the new Master Cylinder fitted by the OP here may get the system working for now, usually, the other components in the system aren't far behind.

[Rorf]

Secret to brake system longevity is in replacing the brake fluid (which is hydroscopic) every 2 years. Water in the brake fluid rusts the cylinder bores which then causes the seals to wear too.

Edited by Rorf, 18 June 2019 - 05:55 AM.