Red oil leaking at brake master when car is running

[audi660]

My automatic urs6 leaks either atf or power steering fluid at brake master and behind the brake pedal inside the car when it is running. My power steering fluid is red like the ATF. Please can someone assist me? Thank you

[K Simmonds]

It shouldn't have ATF anywhere apart from the gearbox, it sounds like you have a leaking master cylinder and the it should be brake fluid in that system.

[audi660]

I just bought the car and looks like it has ATF instead of the green power steering fluid. The power steering reservoir is also very low on fluid. How do I fix this problem?

[K Simmonds]

Without seeing the car it's hard to be certain, however fluid leaking inside the car from the pedal box area should be only be Dot 4 brake fluid, what does the fluid in your brake res look like?

The most likely solution is a new brake master cylinder.

[audi660]

Brake fluid is clear Dot 4. Power steering fluid is red and looks like ATF

[K Simmonds]

Given the low PAS level guess it's possible that the fluid is coming from the steering rack if the seal's for the input shaft that joins to the steering column has failed, in which case you need a replacement steering rack or a rebuild... I've completely disassembled two C4 platform cars and there are no PAS unions or pipe's inside the passenger compartment, though you could try checking for a loose union on the rack body, the rack is mounted fairly high up and fluid could perhaps track inside somehow.

The racks seals won't have liked it being full of ATF, as you rightly say it should be a green mineral oil. The system needs to be fully purged of all the ATF before you fit a replacement rack.

[K Simmonds]

Been thinking about this... The brake booster does get PAS fluid in order to assist the master cylinder, if it's been running ATF then the seals inside that unit could have failed, upon reflection I think this the most likely explanation.