14 replies to this topic

[evl666]

Right...... what causes a hard brake pedal....
Push the pedal to stop, brake pedal feels hard as you push and the brakes work but have to apply lots of pressure to the pedal to make them work/stop the car. I’m assuming this is a stuffed booster not getting vacuum or a vacuum leak but I’ll take all you advice.

Edited by evl666, 31 May 2019 - 10:40 PM.

[Balfizar]

Right...... what causes a hard brake pedal....
Push the pedal to stop, brake pedal feels hard as you push and the brakes work but have to apply lots of pressure to the pedal to make them work/stop the car. I’m assuming this is a stuffed booster not getting vacuum or a vacuum leak but I’ll take all you advice.

Disconnect the brake booster vacuum hose. If it makes on difference to the pedal feel then pretty sure your booster has failed. (or there is a leak)

[rodomo]

History?

[evl666]

I purchased the car non running 6 years ago....stripped it now rebuilding it. New rear brake shoes and cylinders. New brake lines, rebuilt calipers and new pistons/seals in brake master cylinder. Now the car is running the brakes stop the car but needs some effort to do so. Booster rod is set at correct length. Pedal does not have long travel. Rear shoes are set correctly.

Edited by evl666, 31 May 2019 - 11:35 PM.

[S pack]

Disconnect the brake booster vacuum hose. If it makes no difference to the pedal feel then pretty sure your booster has failed. (or there is a leak)

^^^^ Agree, if the booster has failed you should be able to hear the constant hissing sound of air being sucked in through the rear of the booster, with the engine running.

Edited by S pack, 01 June 2019 - 06:43 AM.

[RallyRed]

Did you also change out the short hose from the body to the rear axle housing?. They block up. Your symptoms are like mine when that hose was stuffed, was passing zero fluid.

Easy to check,........jack up,  wheels and brake drums off, car running, get someone to press pedal down....do the shoes move?

[evl666]

brakes work but take effort on the pedal to stop. No way I will hear the brake booster over the engine noise, straight cut gears and all that jazz

[grumpy xu1]

Stethoscope maybe ? You can unscrew the tip.

[evl666]

I’ve got two other boosters just wanted to check if that’s what you guys think it might be before I go to the effort to change them over

[evl666]

Right..... I pulled the check valve off while it was running and it almost stalled. Also if I do the old pump the pedal a few times, wait a minute, place my foot on the brake than start the car test the brake pedal falls a bit more so from those tests I’d be safe to say the booster is ok. So have I still go air in the front brake lines? Or is it the master cylinder? Like I said the rears appear to be doing there job but the fronts are grabbing but just not enough

[grumpy xu1]

I'd be checking that the pistons are moving freely, not the caliper. I've had that before & that's not great. Could be caught up somewhere.

[evl666]

I’ll keep you guys posted. First I’ll bleed them a bit more and if that doesn’t work I’ll pull the calipers off and see what happening

[evl666]

Do I have to remove the brake fail switch to bleed the brakes?

[S pack]

Do I have to remove the brake fail switch to bleed the brakes?

It is recommended but at the very least remove it to reset it when your finished.

Most old switches (the hydraulic parts) are probably seized by now anyway.

[evl666]

Ok guys....here is a up date....
Re bleed the front brakes and I’ve got a much better pedal. Much shorter push + nice and firm. Now the car is not rego’d yet but naughty me took it for a spin up and down the road to test the braking. Some times I’ve got good brakes but other times it’s back to having to really push the pedal to get it to stop. Still air in the lines or not enough vacuum being created? Weird it’s only random. Pedal length doesn’t change it’s just the force on the pedal required to make it stop. It has new pads and discs so wondering if they need to bed in a bit?

Edited by evl666, 08 June 2019 - 11:10 PM.