hey up....

i have just got a MGB GT and it has silicone brake and clutch fluid in it..... i have loads of universal dot 4 in the garage and want to drain the system..... i know that the two dont mix.... but will a simple flush thourgh with the universal fluid be ok? or will i have to get a solvent cleaner? or just stick to silicone now??

whilst on the subject..... the brake peadle is a bit funny..... on hard braking the peadle is nice and firm.. but on slow brakeing the peadle travels down to the floor! there are no leaks, spoke to a company called `past parts` who deal with old vehicles and commercial gear, he thourght that the symptons suggested that the travel was due to the silicone fluid as its not great in 34year old cars!! i put it to him that it may be the seals in the master cyl knackered, but he didnt think that this was the case... and i believe him as i had a service kit in stock and didnt want to sell it to me untill i tries the fluid theory!! also i cant see any leaks in the system and its not loosing fluid!

any suggestions guys???

cheers

bob

Sponginess - very hard to get rid of air in silicone fluid, as I found to my annoyance. Shouldn't go to the floor, but it'll never feel firm.

Getting rid of it - I flushed mine out with DOT4 until it looked clean (the two mixed together looks cloudy). After some research I worked out that you can't chase DOT4 out with silicone, but you should be able to do it the other way round. Time will tell...

David

Nothing to do with the fluid.
The problem is due to the recuperating seal/vavle n the mastercylinder leaking back to the resevoir -- a new repair kit will fix it.

[Edited on 14/1/05 by britishtrident]

Agreed - if you're able to floor the pedal then fluid's leaking through somewhere. Changing seals etc. is easy - even I managed it!
While you're at it, it'll be a very good time to get rid of the silicone fluid, as you can clean all the parts and flush out the pipes (not as time-consuming as it sounds). I found that this stuff always made the pedal 'bouncy'; it may have worked safely enough, but it just didn't feel right to me.

cheers,

David

For anyone needing to buy new brake fluid I recommend you try ATE Super Blue Racing. This is a very good fluid used by many race teams due to its excellent stability. For very reasonable prices try Questmead (http://www.questmead.co.uk/).