Need Help With Brakes Problem. 2000 Mazda 323 Familia

[Trinieagle]

I bleed the lines and changed the disc pads.
The brakes works fine when the engine rpm is going up, but when am driving in traffic and the engine is idling the brakes peddle gets soft and goes low. But if you release and mash again it goes back high.

I also think i have a faulty check valve on the air line between the brakes booster drum and the engine suction manifold.

I checked 2 mechanics and they bleed the brakes and says it working good, and as i start to drive in traffic or slow it goes low again randomly.

Can someone who know about this or had a similar problem please help or give me some advise.

[2 inchez high]

sounds like u may have a leak on one of the lines or something

[Xplode]

so why u bleed the lines to change disc pads ?
normally just unscrew the brake fluid reservoir
proper tools to drive the caliper piston back next time let a mechanic do the work ,you got air in your system.

[trini iceman]

Could there be a problem with the booster or master cylinder?

[02donald]

bleed 4slaves at once thin hose with bottles

[s.serty]

Yea booster or Master cylinder seals is a Bess bet

[Trinieagle]

Dont think its the booster because the brakes dont get hard.

And I dont think it have a leak on any of the lines because the fluid in the reservoir dont go down.
I think it may be the master cylinder because the fluid got discolored or dirty looking.

[BoxEater]

change your cylinder rubbers and rebleed...brake fluid suppose to be clear with a tinge of yellow...over time rubbers begin to disintegrate when exposed to brake fluid..if your brake fluid is dark in colour then the rubber is disintegrating and needs to be changed asap. remember to rebleed the system to ensure there is no air....best bet is to do each wheel separately...one by one

[Trinieagle]

I Got through. Thanks "BoxEater" you where correct.
My fluid was dark, so i changed the rubbers and fluid and it works fine now.

[BoxEater]

glad u got tru op...edit post with (SOLVED) at the end so anyone with this problem can get some assistance

[Abraham2nd]

Its the seals in the reservoir cylinder. They bad thats y its. Dirty. Good luck