Brake fluid very dirty

[electro_boy]

Hi all,

My brake and clutch are not performing 100% at the moment.  The brake pedal feels a little long and spongy and the clutch very rarely is slow to return back up.  

I went to check the brake fluid levels and the level is good very close to the max fill line but the fluid is very dirty.  The fluid is about 2 years old so due a change but is it common to see it very dirty?  I've done about 20K miles and about 5 tracks days since the brake fluid was changed.

Just trying to work out if dirty fluid is reasonable after such use and that could well be cause of the loss of performance or if the master cylinder is on its way out?

Anyway of me checking if the master cylinder is on its way out?  Any other simple things I can check as to why the fluid is dirty (assuming being dirty is not usual).

thanks in advance, Jai

[Bruss]

Dirty fluid is usual. Track day use or any overheating will cause dirty fluid. If it cooked on the first track day it will have degraded and been less than perfect. Change the fluid, then see if your feel and sponginess change.

 

 

[electro_boy]

OK thanks for the reassurance that dirty fluid is normal.  I'll just go ahead an change the fluid and see what happens.

Does brand or a particular fluid matter or as long as its DOT4 it will be fine?

I'm asking as I normally take my car to ES Motorsport to get work done but its a 4h round trip for me so thinking for a simple thing like brake fluid change I'll take it to a local respected garage.  But they may not have some specific high performance stuff in stock.

[Bruss]

Motul rbf. Good for track and road.

 

 

[electro_boy]

Thanks Paul @Bruss I got the brake fluid changed and used Motul RBF660.  The brake pedal is nice and firm with better feed back and the brakes are biting and gripping more so I'm able to get the car stopped properly.  Clutch pedal being lazy to return has not occurred again in the 1 week since the change.   So fingers crossed everything stays working well and master cylinder is still in good shape!

[electro_boy]

Noooo!   Clutch pedal feeling soft and not returning has returned this morning 😢.  

Car was difficult to get moving as the clutch was not correctly disengaging and engaging when moving out of neutral and into 1st! Decided to park it up and take the campervan in to work instead.

I'll try and have a look at it over the weekend.  Is there anything simple things I can check to help diagnose the issue before I take to a garage?

[Bruss]

Bugger!

 

Sounds like a leaky seal somewhere, normally the master cylinder on the Evora.

 

[trcm]

Brake and clutch fluid are the same system on the Evora aren't they...

Could the clutch issues and dirty fluid be down to lack of complete flushing of clutch and brake lines (at the same time) at service intervals?

 

I only say this as my clutch failed shortly after a service supposedly changed my brake fluid, and when it failed they said the clutch fluid was very dark (which to me sounds like an admission they didn't flush it properly).

Edited February 27, 2020 by trcm
typo

[Bruss]

That's a good thought. The clutch does need to be flushed separately to the brake fluid, although at the same time.

 

 

[electro_boy]

Thank you guys.  Just spoke to the garage and they did not flush the clutch line.   Car is pencilled in with them for Wednesday in the meantime they will research the procedure for a Lotus Evora so they don't leave anything out again next time.