Brake vacume nightmares.

[jack.ocholoose]

Changed booster 3 times cannot even get a new one had to get 2nd hand ,changed master cylinder all brakes bled system to the max ,still getting a brake that hisses and sponges down down down ,something tells me it,s the vacume pump as the vacume hozes are fine.
Anyone got any tips apart from removing bullbar ,grill ,radiator then removing vacume pump maybe trying to get a new diaphragm for it ???

 

[Old.Tony]

The vacuum system may have a leak, but if it does, your turbocharger won't work as well as it should. Power should be noticeably less than it was.

The vacuum system comprises the following:

* The vacuum pump, on the engine near the fuel pump.
* The brake booster
* The turbocharger "Boost Control Solenoid" (BCS)
* The turbocharger actuator

The BCS is a common problem item but usually its failure is to not supply vacuum to the actuator and this means no boost at all and substantially reduced engine power.

The actuator itself has a diaphragm in it, the vacuum pulls this up and the rod beneath moves the vanes inside the turbo. It's very rare that this diaphragm fails, but it has happened before.

So, questions:

1) Have you tried simply blocking off the vac hose to the booster and trying to depress the pedal and see how much travel you get? This would completely negate the vacuum system from the issue.

2) Have you checked that you're not losing hydraulic fluid at the wheels (front and rear) or at the ABS unit?

3) Is the ABS light on when the engine is running? This may or may not also bring the 4WD light on.

4) Does the engine seem to lack power?

 

[tweak'e]

The vacuum system may have a leak, but if it does, your turbocharger won't work as well as it should. Power should be noticeably less than it was.

he has zd30 so turbo is not vacuum controlled. in fact no D22 has a vacuum controlled turbo. only the D40 and D23 has them.

 

[tweak'e]

Changed booster 3 times cannot even get a new one had to get 2nd hand ,changed master cylinder all brakes bled system to the max ,still getting a brake that hisses and sponges down down down ,something tells me it,s the vacume pump as the vacume hozes are fine.
Anyone got any tips apart from removing bullbar ,grill ,radiator then removing vacume pump maybe trying to get a new diaphragm for it ???

is it still spongy when the engine is not on (and run out of vacuum) ?
if so its air in the brakes.
i'll have to double check but common place people forget to bleed is the proportional valve above the rear axle.
another thing worth checking is the rear drums. make sure they are not worn out and they are not sticky and are adjusted correctly. auto adjusters are known to not work in many vehicles. many ***** mechanics won't adjust the brakes and expect the auto adjuster to adjust them into position.

edit: in the book there is a procedure on what order they get bled in.

 

[Old.Tony]

Thanks @tweak'e , I missed that one.

 

[jack.ocholoose]

Just ordered vacume pump can this job be done without taking off bullbar grill aircon ,radiator for access.

 

[jack.ocholoose]

Could it be the diaphragm in this ,I remember these little suckers having something to do with that whole system that can dramatically change it,s performance

 

[jack.ocholoose]

The vacuum system may have a leak, but if it does, your turbocharger won't work as well as it should. Power should be noticeably less than it was.

The vacuum system comprises the following:

* The vacuum pump, on the engine near the fuel pump.
* The brake booster
* The turbocharger "Boost Control Solenoid" (BCS)
* The turbocharger actuator

The BCS is a common problem item but usually its failure is to not supply vacuum to the actuator and this means no boost at all and substantially reduced engine power.

The actuator itself has a diaphragm in it, the vacuum pulls this up and the rod beneath moves the vanes inside the turbo. It's very rare that this diaphragm fails, but it has happened before.

So, questions:

1) Have you tried simply blocking off the vac hose to the booster and trying to depress the pedal and see how much travel you get? This would completely negate the vacuum system from the issue.

2) Have you checked that you're not losing hydraulic fluid at the wheels (front and rear) or at the ABS unit?

3) Is the ABS light on when the engine is running? This may or may not also bring the 4WD light on.

4) Does the engine seem to lack power?

done all of these checks no abs engine power seems to be fine.

 

[jack.ocholoose]

The vacuum system may have a leak, but if it does, your turbocharger won't work as well as it should. Power should be noticeably less than it was.

The vacuum system comprises the following:

* The vacuum pump, on the engine near the fuel pump.
* The brake booster
* The turbocharger "Boost Control Solenoid" (BCS)
* The turbocharger actuator

The BCS is a common problem item but usually its failure is to not supply vacuum to the actuator and this means no boost at all and substantially reduced engine power.

The actuator itself has a diaphragm in it, the vacuum pulls this up and the rod beneath moves the vanes inside the turbo. It's very rare that this diaphragm fails, but it has happened before.

So, questions:

1) Have you tried simply blocking off the vac hose to the booster and trying to depress the pedal and see how much travel you get? This would completely negate the vacuum system from the issue.

2) Have you checked that you're not losing hydraulic fluid at the wheels (front and rear) or at the ABS unit?

3) Is the ABS light on when the engine is running? This may or may not also bring the 4WD light on.

4) Does the engine seem to lack power?

Ya bout to just take out the radiator and take the fan off for access .was gonna try see if the local brakes dude could identify the problem exactly using any sort of technology but he won't answer his phone.

 

[tweak'e]

Could it be the diaphragm in this ,I remember these little suckers having something to do with that whole system that can dramatically change it,s performance

thats the egr butterfly actuator. you can easily block off all the vac to those at the solenoids. that would tell you if you have a leak in that area.

 

[jack.ocholoose]

Took out vacume pump ,could vacume problems be due to a lack of oil as when I tapped my sump I noticed a thud like empty ,pulled the pump apart ,not much to it blew in through tube attached got a gurgly sound like a valve ,is that the one way valve everyone who thinks they know about these things is ,a brake mechanic tried to tell me it was on the firewall ?????

 

[jack.ocholoose]

is it still spongy when the engine is not on (and run out of vacuum) ?
if so its air in the brakes.
i'll have to double check but common place people forget to bleed is the proportional valve above the rear axle.
another thing worth checking is the rear drums. make sure they are not worn out and they are not sticky and are adjusted correctly. auto adjusters are known to not work in many vehicles. many ***** mechanics won't adjust the brakes and expect the auto adjuster to adjust them into position.

edit: in the book there is a procedure on what order they get bled in.

No it,s tight when engine is off.Cant get a book for a d22 06 just a dodgy cd

 

[jack.ocholoose]

O.k pulled out the vacume pump ,pulled it open ,cleaned it ,blew in through the valve works o.k sucked through got nothing ,so the check valve is o.k going to put it back in tommorrow ,and do some other checks as ,it,s obviously not the check valve or the vacume pump ,any other idea,s on what could cause this problem in the vacume system???anybody.

 

[tweak'e]

i highly doubt its the vacuum system.
if you can push the pedal down with engine running but its hard when its not, then vacuum is doing its job. vacuum failure results in hard brake pedal (like when engine is off).
if pedal keeps going down to the floor its typically master cylinder piston seals.
or the brakes are out of adjustment (or loose wheel bearings) and there is a lot of pad travel to take up. that can make brakes feel soft. otherwise typically its air in the system somewhere.
also make sure you do not have a brake hose thats bulges under pressure.

 

[tweak'e]

still getting a brake that hisses and sponges down down down

can you give more detail on the symptoms?
check the noise is not the spring or pivot points of the pedal.
if you rapidly push the pedal, the pedal should go lower on each pedal press (as per the manual/book/cd).

also does it have ABS ?

 

[Horatius]

Agree the symptoms are more like it has, or is getting, air in the lines. Could be many reasons for that, but also for whatever reason some D22's seem to be a pita to bleed properly. Never had that problem but I know others have.

I didn't think any of the zd30 models have abs (in Aus at least)?

 

[jack.ocholoose]

Test drove this morning and brakes are locked on ,Siri reckons it,s the master cylinder ,just ordered another one from da wreckers

 

[jack.ocholoose]

So all one way valves in brake line go so vacume can be sucked into engine ,correct.as that is the way I put em on yesterday.

 

[jack.ocholoose]

My bad that was all one way valves in vacume line go towards vacume pump,is this correct or is this a big mistake.

 

[tweak'e]

afaik there is only check valve on the vacuum system and thats at the vacuum pump and air should flow to the pump.