Brake Pedal Very Stiff - Brakes Still Working

[No Crust Racing]

Spoke to brake guy again.

He said based on what I've said the booster sounds fine to him and if it was never firm before hand (with the same brakes) it shouldn't be firm now.

He suspects my adjustment of the rod to re-position the pedal might be the issue and has given me some notes on checking rod to master clearances, there should be some travel on the pedal and I'd say there's little if any.

I'll take a look. That might help the initial pedal firmness but I can't see how it will help how it feels once the booster rod comes in contact with the master.

[Bushy]

Yeah I don't know mate, I'm no brake expert I was just making the point that I don't think it's the pads based on my experiences with them/what you said.

Throw those spare pads at it and adjust master rod and test. Those are the only easy options bar testing a different BM.

[75coupe]

I run the same pads and have punished them at track, just had the fluid get too hot replace fluid, bled and punished them again, never a hard pedal...

I dont thinks its pads either

[No Crust Racing]

Thanks for the feedback.

I'll test it when I can but it must be either stuffed master (unlikely) or due to the booster adjustment.

I'm hoping to get some time on it tonight.

[89CAL]

Have you unplugged the vac feed to the booster to see if it feels any different? I imagine if it feels the same then the problem is the booster. Would be the easiest way to rule it out

[No Crust Racing]

The booster itself has been tested with and without Vac, and behaves as expected.

I'll test the pedal without it, but really that's no different to me pumping the pedal then holding it down and starting the car.

I'm hoping to get a few mins tonight and I'll focus on the booster rod length I think.

[No Crust Racing]

Well still confused.

I wasn't 100% clear on what he actually wanted me to measure, but I can say the rod on the booster has clearance to the master and is not hard up against it.

What I did find is that with the booster removed from the car and my finger over the fitting where the vac hose would connect. I could operate the booster by hand (which I thought he said I shouldn't be able to do but I'm not sure if he went with it on or off the car).

Either way, when the rod extends out the front I can feel air moving past the rod which I would assume is supposed to be air tight.

I have it with me and will drop past the brakes place tomorrow to discuss.

[GTSBoy]

My local pizza shop is Roman's in Salisbury. Tell them you want a 1/2 Seafood, 1/2 special sent to Brad.

[No Crust Racing]

Lol what

[89CAL]

GTSBoy said he would put money on air leak from booster.

I said booster

We weren't just guessing. I've had the complete opposite in a non turbo were the brakes were soft all the way to the floor but still worked normal

Problems with brake effort with normal brake function are almost always booster related

[scotty nm35]

And they only use rubber seals and a big diaphragm after all.

[No Crust Racing]

That's enough to prevent pregnancy in most cases...

[Plattsy]

That's enough to prevent pregnancy in most cases...

try telling that to my wife.

f*ken.

[No Crust Racing]

"In most cases"

You must have powerful swimmers my man.

We were fine with just the pill until we decided it was time.

Now we have our very own Tamagotchi. I mean Toddler.

[89CAL]

This thread is going way off topic...........

[No Crust Racing]

All the best ones do

I'll update later when I've spoken to Brakes man.

[89CAL]

Can he rebuild boosters? I'm not sure how easy they are to rebuild.

Might pay off to ring a wrecker and get a new booster on the go anyway. Shouldnt cost too much

[No Crust Racing]

I reckon I should be able to grab one locally.

I'll confirm it's stuffed first as I don't know enough about properly testing them, I am only assuming that air I felt is a problem.

I'd prefer to have it confirmed.

[89CAL]

No air should escape AFAIK. But seen as they are under vacuum I will have to think about it a bit more.

The vacuum does disappear when you press the pedal a few times with the car off, But I think that is something to do with the 1-way valve and compressing the booster chamber. I'm not real sure to be honest lol. Will have to really think about it

EDIT: O.K, research done. the back (pedal side) of the booster should let atmospheric pressure into the booster when the pedal is pressed. So I think you said you are getting air on the other side of it so that might be your problem. Master side should always be vacuum, pedal side is vacuum until pedal pressed.

HowStuffWorks was awesome when I was 14, still awesome now that I'm 24 Click the link and it should help you understand it. It also shows how come you only get a few pedal presses before losing all brake boost assist

Edited June 20, 2014 by 89CAL

[No Crust Racing]

I read all the same stuff, hence taking it in.

Guy behind the counter was very helpful and said while he was not 100% it was definitely faulty, it should behave as you mentioned above (and as I can get one for $50 second hand easily enough to just swap it out).

I'll grab another and see how it goes.