Problem with brake, NX2000

M0J0 · 04-18-2010, 09:30 AM

So I changed the old rubber brakelines for SS ones, and the rotors for new, slotted ones, and changed pads.

Unfortuntely, I also made the mistake of pumping out ALL of the brake fluid, before swapping my brakes.

It's mushy at first, but when I pump the pedal a little, it's a lot firmer, and the stopping power is great. But when I wait again, the pedal is mushy again. This is with the engine running. When the engine is shut off, the pressure is good.

Also, I tried pumping the pedal really fast, but that made my engine stall.

I've bled the system 4 times now, the last time I used half a liter per wheel. No bubbles whatsoever.

I'm out of ideas. Last thing that I can think off is a problem with my Master Brake Cilinder. Will bleeding the MC cure my problems with my mushy pedal?

Cheers!

Sander

Viperoni · 04-18-2010, 09:43 AM

I'd definetely try bleeding the MC, if all the brake fluid leaked out of it, then you definetely need to bleed it.

M0J0 · 04-18-2010, 10:16 AM

Right, I managed to get some more air out of the MC, by using this valve:

The pedalfeel is a little better now. However, there's 2 pistons in the cilinder, and it seems like the aforementioned valve only connects to the piston closest to the firewall.

On the other side of the MC is this:

Is this where I should bleed the other piston?

Blair · 04-20-2010, 01:53 AM

Did you bleed the MC first, and then the calipers in the correct order?

1. Left rear
2. Right front
3. Right rear
4. Left front

M0J0 · 04-20-2010, 04:10 AM

No, bled the MC only after I bled the rest. About the order, everyone seems to use a different one. The FSM says they have to be bled the way you say I have to, while others say I have to bleed them from longest brakeline to the shortest.

eric96ser · 04-20-2010, 09:47 AM

Bleeding from furthest to closest is the beast way to change fluid, but you need to go back and bleed in the order Blair posted. Bleed the MC first, then the brakes in the order the FSM states. I bleed brakes a different way from how the FSM tell you. I use a long piece of clear hose, have someone pump the brakes a few times and hold it while I open the bleeder. With the bleeder open, I have the person pump the brakes in nice, even movements. With the clear hose, you can see if there is air in the line, and the fluid keeps air from getting back into the system. I've done this dozens of times, and the brakes always feel great.

siberian21 · 04-20-2010, 11:06 AM

I'm having the same feeling from my nx as well and have yet to remedy the problem. I'm thinking of just replacing the mc and seeing if that cures it.

NXtacyNZ · 04-20-2010, 03:33 PM

I had this exact problem with my brakes when I swapped my calipers over. I bled the system until no air came out, but it still felt mushy. I bled the system for ages (just kept recylcing the new fluid) and the odd bubble would come out and it fixed the problem.

M0J0 · 04-20-2010, 04:36 PM

Ok, so when I bleed the MC, I can use the the bleeder shown on the first pic? Or do I have to bench bleed it?

LSpec · 04-20-2010, 08:19 PM

i had that problem when change to ss lines, I did exactly what they said, but I found that the air was in the left rear line, I purge a lot until the pedal feeling change that solved the problem... dont forget to refill hope you can solve this, i know is frustrating

Blair · 04-21-2010, 01:45 AM

Quote:

Originally Posted by M0J0

Ok, so when I bleed the MC, I can use the the bleeder shown on the first pic? Or do I have to bench bleed it?

For simplicity, I'd try it on the car first.

johonjoseph · 02-08-2011, 06:56 AM

Brake looses its power either by leak in brake master cylinder, Brake hose, fluid reservoir, improper brake adjustment or problem in brake power booster even.

Brake power booster works on the principal of difference in pressure to assist rider in application of braking. you should check out the working of brake power booster very properly .... as you mentioned in your problem that pedal doesnot work at the time of engine running. so i assume there you once to check out power brake booster too..

i have wrote an article on the solution of braking problems , may be useful regarding brake bleeding and any minor mistake in bleeding. I would be thankful to you .... if it works ..... Fixation and Finding Brake Problems

PhorB13 · 02-08-2011, 09:14 AM

You are going to want to remove the brake line connections, and bleed the MC through the valve in the first picture. Leave the other one alone. THEN, reconnect it and bleed the calipers in the order that Blair mentioned. You might have to do it multiple times to get all the air out.

M0J0 · 02-09-2011, 02:38 PM

Thanks, Phor, will do that when upgrading to SS Braided ones. Brakes are okay right now, not awesome, but they suffice. Brake feeling is better than before (braking a second time shortly after pushing in the pedal for the first time doesn't result in a stiffer pedal anymore).

Also, old topic is old!

MissSr20DE · 09-08-2011, 12:23 PM

i have a question about this i have to do my brakes now (replacing the lines) i just wanted to know are the metric or SAE? im trying to find the difference i know by the different flares but they wont give me the lines unless i know what kinds they are. the lines are so brittle they break in your hand so i really cant tell. any suggestions thanks!