help "brake problem"

[Sheep]

Hello i just want to ask if any of you guys know what might be the cause of this...
vehicle is a 2000 strada

My brake was perfectly ok, no problem of whatsoever but I decided that it was time to change the brake fluid; I had my mechanic bled it and poured new spcified brake fluid in the reservoir we are perfectly sure that we did it the right way because he was already a old mechanic and I did managed to supervise him while he was doing it having a chilton manual as my reference

What happend after the change in fluid the braking was ok but i noticed that when the engine is not fully revving the brake pedal tends to bottom out the same is also when traversing inclines or declines.
When on highways and when the car is running fast there is no problem of whatsoever "talagang malakas ang preno" it doesnt bottom out.

Here is a list in chronological order of what we did after encountering the problem:

1) bled it a few more times i think we already used up 2 liters of brake fluid
2) repaired the brake master cylinder with a repair kit
3) got a new brake master cylinder assembly including the plastic cup
4) adjusted the load sensing valve (LSV)
5) replaced the LSV
6) replaced the brake pump attached to the back portion of the alternator including the alternator with a new one.

I already spent more than 50k for the damn brake system and up to now the problem aint solved yet in fact almost the whole brake system was replaced ang natira na lang ay yung hydrovac but we are positive that this isn't the problem.

any of you guys encountered this?

thanks in advance for the help

[theveed]

May check valve ba from the engine to the hydrovac ang Strada? Sa benz kasi pag nangyayari yan yung check valve may kasalanan

[BlueBimmer]

50k! for brake repairs wow..

[Sheep]

theveed
thanks i did check yes it has one i will ask my mechanic to check it later

bluebimmer sad to say yes inabot na nga ng ganun

up ko lang baka may ibang inputs

[H1Tman]

50k! for brake repairs wow..

mr speaker, i second the motion!

[jim]

grabe yung 50K for break repairs. mukhang OEM lahat ang ginamit mong replacement parts. ako noong nasira ang hydrovac ko (for toyota hilux) I went to evangelista and got a surplus for just 2.5K (original is 10 - 12K) and replaced my brake master cylinder with a replacement one (bago) for only 2.8K. nagbo-bottom out ang brake pedal ko noon dahil yung fluid pumapasok na sa hydrovac. up to now (3 years) di pa nasisira yung surplus hydrovac ko ;)

[OTEP]

Sa Vitara yung brake master din ang problema when we got it. No leaks ended up on the garage floor because all the leaking fluid went into the hydrovac system.

A new master was Pnp 8K. Well worth it. Kaso bopols yung mga nag-install. Ang mahal pa naman ng labor (Php 1,000.00) ata kasama kabit ng new pads.

Pinatawag ko pa si cousin Ferdie ni afrasay to rectify the botched install (Php 200.00 lang siningil samin).

Advice ko sayo, get another mekaniko.

[wildthing]

Sayang, sa 50K maigi pang sa casa mo ipinasok...hindi na magkakalayo ang presyo...anyways, in my limited experience ang major cause lang ng bottom-out ay presence ng hangin sa linya....ang hindi ko ma-gets ay mukhang ibinleed nyo naman ng tama (naka 2 litro ka nga diba...taka lang ako, kami hindi man makaubos ng 500ml sa bleeding). Hindi kaya me problema sa bleeding process?!? kasi unang-una nagreplace ka lang naman ng brake fluid sa simula.

the air pressure assisted hydrovac could also be a cause, na pepressure test din yun linya yata kung enough pa ang pressure coming from that air line...

my 2 cents.

[speedyfix]

agree... get a new mechanic.

what car is this btw?

[afrasay]

2000 Strada.

Did you check the hose from the alt/vacuum pump to the hydrovac? It could have a small leak somewhere.

[oldblue]

What happend after the change in fluid the braking was ok but i noticed that when the engine is not fully revving the brake pedal tends to bottom out the same is also when traversing inclines or declines.
When on highways and when the car is running fast there is no problem of whatsoever "talagang malakas ang preno" it doesnt bottom out.

how 'bout the power brakes: vacuum booster? from what I read may konti hangin lang pumasok dito, maiiba na yun timpla ng break. this is totally independent (am not sure??) ata sa master cylinders & valves na na-check mo na.

anyway baka lang ... http://auto.howstuffworks.com/power-brake2.htm