Brakes

[Ewood11]

Hi all,

My brakes on my navara have become soft. No leaks and the shoes and disc pads all seem fine. So I replaced the master cylinder, bench bled it, then bled all the lines. No air bubbles. But the brakes are still soft. I wondered if there could be air in the ABS unit. I’ve got a workshop manual and it says if you suspect air in the hydraulic control unit to take truck into a dealer who can do an autobleed. Any thoughts?

 

[Old.Tony]

It could also be a vac leak (if you have a vacuum controlled turbocharger - D40 from 2013 or older, I think). The leak may not present in poorer performance immediately (particularly if there aren't any Hiluxes to leave behind at the traffic lights).

Go over the vac lines, look for any hardening of the inner rubber tube (usually at the ends, and it makes the hose easy to turn on the connector). Look for signs of cracking. Ignore the outer sheath, that's just to protect the inner hose. If you have to replace it, about 3 metres of 3mm (inside diameter) vac hose will give you enough to replace the lot.

 

[tweak'e]

the other common thing for "soft" brakes is the drums being out of adjustment. pretty common for auto adjusters to wear and not work. but also if the drums wear out.

 

[Ewood11]

It could also be a vac leak (if you have a vacuum controlled turbocharger - D40 from 2013 or older, I think). The leak may not present in poorer performance immediately (particularly if there aren't any Hiluxes to leave behind at the traffic lights).

Go over the vac lines, look for any hardening of the inner rubber tube (usually at the ends, and it makes the hose easy to turn on the connector). Look for signs of cracking. Ignore the outer sheath, that's just to protect the inner hose. If you have to replace it, about 3 metres of 3mm (inside diameter) vac hose will give you enough to replace the lot.

Cheers mate. I’ll check the back lines and see what’s going on with them. Are they east enough to locate. I have a workshop manual so that should direct me to correct pipes.

 

[Ewood11]

the other common thing for "soft" brakes is the drums being out of adjustment. pretty common for auto adjusters to wear and not work. but also if the drums wear out.

Cheers mate. I’ll check this out at the weekend.

 

[Old.Tony]

Cheers mate. I’ll check the back lines and see what’s going on with them. Are they east enough to locate. I have a workshop manual so that should direct me to correct pipes.

They're easy to spot. Find the turbocharger, one of the vac lines runs out of the top of this (the round gold part on the turbocharger is called the "actuator" ) and heads to the Boost Control Solenoid (BCS) that has been problematic in the past (although I don't suspect it will leak vacuum). There are other hoses heading off the BCS, including one that heads over the top of the engine to the vacuum pump.

 

[Ewood11]

They're easy to spot. Find the turbocharger, one of the vac lines runs out of the top of this (the round gold part on the turbocharger is called the "actuator" ) and heads to the Boost Control Solenoid (BCS) that has been problematic in the past (although I don't suspect it will leak vacuum). There are other hoses heading off the BCS, including one that heads over the top of the engine to the vacuum pump.

Cheer Old Tony I'll check them out.

 

[Ewood11]

They're easy to spot. Find the turbocharger, one of the vac lines runs out of the top of this (the round gold part on the turbocharger is called the "actuator" ) and heads to the Boost Control Solenoid (BCS) that has been problematic in the past (although I don't suspect it will leak vacuum). There are other hoses heading off the BCS, including one that heads over the top of the engine to the vacuum pump.

 

[Ewood11]

Thanks mate, I went over the vac lines and they all seem in pretty good condition, some appear to be pretty new. I'll check th edrums and the auto adjusters too

 

[Ewood11]

the other common thing for "soft" brakes is the drums being out of adjustment. pretty common for auto adjusters to wear and not work. but also if the drums wear out.

Could the auto adjusters be worn out? I suppose I should take the drums off and inspect them but I suppose its worth asking the question?

 

[tweak'e]

adjust them manually first.

 

[pistol-W]

Strange everyone told me to drive backwards and while holding the handbrake button down... keep pulling the h/brake on & off... it automatically adjusts... equally... maybe to easy to try ?

 

[tweak'e]

Strange everyone told me to drive backwards and while holding the handbrake button down... keep pulling the h/brake on & off... it automatically adjusts... equally... maybe to easy to try ?

yes there is a few tricks like that. however the engagement teeth/arm wears fairly quickly so the auto adjusters often do not work, so your left with manually adjusting them.
if your doing a brake shoe change its worth filing them back into shape.