Hey all, I have a weird brake malfunction that I need help with. Its on a 93 Pulsar (auto). Sometimes when braking, when you put your foot on the brake, they momentarily (1~2 seconds) dont work. This happens both when slowing down, and at a stop - when at a stop, it causes the car to lunge forward, then the brakes grab again. It has already caused a minor scrape, but isn't consistant - maybe on a fortnightly basis. Any ideas what it might be? Its obviously pretty dangerous

checked the brake fluid? might be worth while to do a bleed.

Man.. take it to a mechanic ! Brakes are all that stops you becoming a mushy paste underneath a semi-trailer, dont mess around.

x2. And if possible, do not drive it untill then.

check the wheel bearings aren't loose. This can cause all sorts of intermittent problems. only way to check is to lift the wheel off the ground, and give it a good shake, and then remove it and the disc to have a good look.

could also be a loss of vacuum causing the booster to lose power - check for worn/damaged vacuum hoses.

another vote for straight to the mechanic!



- mad89

Yeah, the mechanic is going to be the first place I take it - the only problem is I dont want him to not be able to find it... Thats why I'm trying to get possible reasons/causes. Hopefully they'll be able to sort it out without too much drama..

I was a mechanic for 6 years.

That doesnt mean its a good idea for this guy to try bleeding brakes and/or replace his own lines.

Before you start your car in the mornings, is the pedal ever stiff?

Sounds to me like you're master cylinder

Not a nice thing to have let go in an emergeny situation, been there done that.

Thank God for the cable handbrake



Get you're car to a brakes mechanic ASAP.

I didn't say to replace the brake lines.

If the pedal goes stiff intermittently, it's likely a problem with the brake booster or vacuum hoses in the engine bay. This will mean that the booster is a bit sluggish to help with the braking.

Also, it could be the wheel bearings are a bit loose. Loose wheel bearings allow the disc to push the pads apart, making them have to move further before they grab on to the disc.

Slicer ive had that every now and then but mine is because my car has a dynamic hill holder(Clutch brake) and i because of habit make it lock always when i park my car in the shed(2 of the 4 car spaces are on a big slope)

what about just air in the brake lines?

hence bleeding = problem solved (provided no more air gets in)

Well if it's air, then I'd be more concerned and recommend a mechanic, as it could then be the calipers sucking air, or the master cylinder.

If you sit with foot on the pedal, does it slowly sink to the floor?

Is it a hard pedal that just doesn't apply the brakes when pushed...

That will answer the question of what is the problem... If the pedal isn't 'soft' then unlikely to be air.

Most of the time its normal - its only on these rare occasions it acts up. And considering the owner is my better half, I really wanna sort it out. Sounds like a brake mechanic is the best bet...