Brake problem

[skycon]

I got itcy and went up to genting visited uncle lim yesterday night. On the way back to KL right after gothong jaya, suddenly my brake got no grip at all. What happen was during a down hill corner when I press on the brake as usual, the brake-pedal just travelled all the way to the bottom and the brake is not stopping the car as usual. I quickly step-down the gear and use th engine brake to slow down the car. Since is so dark (way pass midnight) I got no choice but slowly drive it in 20km/h and use the little brake remaining and lower gear to bring the car down the hill. Every press-on the brake-pedal just travelled all the way with no hydraulic pressure at all, and only little brake effect. damn scary!Once reached the pondok polis down there, i stopped and inspect what's wrong. Can't find anything. No brake burning smell. Brake indicator is NOT on. ABS light also not on. No fluid leak undercarraige. WTF! :dunno: After resting for awhile, i started the car and continue my journey back. Surprising, everything back to normal. The brake works again. Every press the brake-pedal will have hydraulic pressure and only travel half way like normal to stop the car. So till now the brake works fully ok. What could be the problem ?? Did I overly cooked the brake earlier so boiled the brake fluid ? What else should I check ? Do u think any problem with the master pump ? Should I change the hoses to steel braided ? Really scare. Oh, btw, where to check the brake fluid level on e39 ah ? can't find any..

 

[Bmmad318i]

On the way down from genting u should b using engine brake to slow down u're car instead of using the brakes too often as the brakes will heat up too hot and causes the brake to b less effective. Happened to me also .....long time ago lucky never langgar somebody behind.

 

[jarance]

check your brake fluid level. you might need to bleed the hydraulic as there is a possibility of air lock in the master cylinder. This might happen when your brake fluid is low.
Surprising your brake fluid alarm light did not come on.

For e36, the reservoir for the brake fluid is located near the fire wall on the driver side.

 

[skycon]

its kind of hard to keep "step down" the gear manually via steptronic ah.

I can't seem to find the brake fluid reservoir. I read that it is hidden somewhere beneath the microfilter housing ?

 

[jarance]

Originally posted by skycon@Apr 30 2005, 07:41 AM
its kind of hard to keep "step down" the gear manually via steptronic ah.

I can't seem to find the brake fluid reservoir. I read that it is hidden somewhere beneath the microfilter housing ?

I attached a pic from etk, have a look for something that look like below. The brake fluid reservoir should be located in the engine compartment.
if you don't know where the engine compartment is, try looking under the hood in the front of your car.

 

[flash]

Sounds like you cooked your brakes on your down Genting, which is pretty normal if you have been "riding" your brakes all the way down. The "proper" way to go down Genting is using engine braking in conjunction with the brakes. That way, you would not overcook your brakes and your engine.

Oh, how to use engine braking? Just shift your auto out of "D" into "2" or even "1". Try to maintain a lower speed and just tap on the brakes to slow down and not hold the brakes till kingdom come.

Been there and seen so many cases of overcooked brakes at the police station down at the foothill (and have almost been a rear-ending victim when a dumbass driver tried to follow my speed down Genting).

Used to work up in Genting and have been driving up and down between the hilltop and Awana in my jalopy and have not suffered brakes problems. Touchwood. h34r:

 

[teejay]

when was the last time you changed your brake fluid?

my thoughts ,
there could be a relation between altitude, surrounding pressure and fluid dynamics, and a possible air lock-as per jarance, that cause fluid breakdown, maybe jarance/albundy can give a deeper explaination.....

possibly moisture accumulated due to altitude, pressure and temp buildup from the earlier braking

suggest you do a full fluid change, and get the master cylinder checked at the same time

 

[E34EuroTouring]

I guess most people pointed out the obvious in your brake fluid change. I strongly recommend, you flush them for new brake fluids and ensure it is done yearly. Brake fluid is hygroscopic so it takes water over time and becomes less effective especially when you work those brakes hard.

There is another thing, to check the SLAVE cylinder. This part could have a "stuck" piston when it gets old. Good luck and drive safely.
:nyehehe:

 

[Ghostrider-SG]

I think you kenna brake fade...your pads must have heated up and cause a glassy layer to form on the pads thru making your brakes super smooth and useless.

When going down hill...do not rely on your brakes alone, use the engine to slow the speed down as well. You will not drive in 5th gear downhill rite ? So shift the drive out and select a lower gear.

Thank goodness nothing happen.

Try fitting slotted rotors...they help to deglaze those glassy layers.

 

[skycon]

Thanks all bros for yr comments.

Yeah, the fluid has not been changed for a long long time as I can remember. Will be heading to get it totally replace and rebleed this week. I guess might as well get it change to those higher boiling point type like the Motul RBF or ATE Super Blue, depends on which I can find. How many liters of fluid you reckon I would need for total change of it ?

Oh, btw, it seems that the e39's brake reservior is hidden out of sight fr engine compartment. U need to remove the microfilter housing (by tools) completely 1st only can access to it. Really stupid design if u ask me!

 

[OSFlanker]

Be sure to use DOT 4 base fluids, heard DOT 5 not suitable for ABS equipped cars. Aside from the brake fluid, the discs & pads are also not built to take extreme heats unless you are on cross drilled / slotted discs which dissipate heat better and also higher temp pads.

Another way to slow the car down without brakes is of course by going sideways, but I would not recommend it

 

[ALBundy]

Yeah use Dot4 as I heard Dot 5 will erode the rubber seals. Anyway, I think the ori brakes on the e39 is good enough so the culprit should be the fluid. And I never speed on the way down from genting, and have seen many accidents there. I do however, accelerate on the way up which I find to be more exciting and relatively safer.

Rgds

 

[JCKL]

skycon

I've a similar experience during the SIC track day. After a few "hot" laps, I came in to the pit & let the car cooled down, the car rested for about 15-20 min. When I wanted to go out again, started the engine, stepped on the brake pedal & it went all the way down without resistant, scared me then. I released & pressed again, it was back to normal. Until today it's been okay.

 

[OSFlanker]

This is what you need :

http://www.911zentrum.com.my/race_sport_equip_brake_disc.htm or http://www.dba.com.au/default.asp together with higher temp range pads (but still for street use).

Best I heard is Mintex CTech 1144 but the pads are close to RM700 per pair (dun even dare ask how much are the rotors!)....

 

[bal3056]

Gone up & down genting million times (pardon my exaggeration) using Jap cars and never had any problems. My Honda had seen genting more times than I can remember using other makes. No brake fade, overheating or any problems. Maybe just lucky so far.

But haven't taken my Bimmer yet to genting or even long distance, coz the fear of anticipation of problems which i've heard time and time again. But still want to own Bimmer-lah ... what to do!!