More Brake Problems

[Guest FRANK J]

Perhaps you can help before ma heed blows up - K reg ZX 1.9 TD - brake problem - suicidally little braking power - is this system particularly hard to bleed??? Pedal goes to floor like no fluid in system or bad master cylinder problem - pumping pedal gives some but little pedal but feels spongy and even full leg pressure gives little braking. If only the spongy symptom was shown I would have thought the servo vacuum was not working. However I have tried 3 different scrap yard servos with no joy. I have also done the following:-

 

-fitted two ex scrapyard calipers

-checked front discs for distortion

-checked front pads for wear

-changed brake fluid

-looked for fluid leaks

-fitted brand new master cylinder

-fitted brand new front rubber brake hoses

-fitted brand new front brake pipe (one side only)

-fitted brand new rear brake cylinders

-fitted brand new rear brake shoe adjusters (and i know that they are right and left handed)

-I have tried bleeding the system

 

Have i gone mad!! Can it be that there is still air in the system after bleeding the system so many times???

 

I will try and make sure that the rear break shoes are adjusted next as you have pointed out above. I will recheck to make sure the calipers move properly. I must say that the handbrake is very good.

I am now lost for words - HELP MA BOB

 

Frank J

[Guest Colin Hunter]

Hi Frank.

 

Well! It seems you've already covered all the bases on this one! The only thing I can add is, did you bleed the brakes by pumping with the pedal, or with a pressure bleed kit, e.g. "Gunsons eezybleed"? Some systems don't appear to like being bled any other way, especially if the vehicle is fitted with ABS. I invested in an eezybleed kit some time ago and it really makes the whole thing so much easier and hassle free.

 

Also, did you check out the "new" callipers (Pistons & slides free) before you fitted them? Also that the front pads were free in the carriers and able to move freely.

 

Sorry can't be more help :rolleyes:

[kfk]

I seem to remember that the ZX with abs was troublsome to bleed.....and if memory serves me correctly it involved the use of diagnostic comuters to open the solenoid valves to allow the fluid to pass through the abs vave block.

 

You have spent a great deal of time going over the car already.....but a suggestion for you.

 

All brakes have a flexible pipe going to them, if your able, before doing anything else try clamping the pipes (gently) and pump pedal to see if it becomes less spongy.....maybe do rear first then front.....then try diagonally. If its related to adjustment in the rear drums or or a caliper/disc fault the pedal will become firmer as clamping will eliminate that part of the circuit.

 

If you have abs check to see if it has a bleed valve on the abs unit.....try bleeding the unit...might not haveone so if you cant see it dont worry.

 

As far as the servo is concerned....if its working it makes the pedal spongy....if it isnt it feels like standing on a brick.

 

To test the servo, with engine off depress brake pedal several times to evacuate all vacuum.....having done that apply pressure to the brake pedal....and start the car......the pedal should go down, if it does it is having a vacuum applied to it and the servo isnt leaking. If the pedal doesnt move when you start it you could have a punctured servo diaghragm, it may be fitted incorrectly, the pipe going to it could be leaking or the vacuum pump on the end of the cylinderhead may be faulty......if you remove the vacuum pipe from the servo with the engine running it should suck on your finger!