Brakes not working after sitting over a year.......

[PQ]

So here is the situation.

As many know my car has been sitting since June last year (2013) when the cam went bad and ruined my engine.

Well it's all rebuilt and upgraded and I have finished everything but tuning.

By all indications I should be able to drive it nicely to the tuners.

So I fire it up and want to check that it's good to go and drive it around the block. Get to the end of the driveway and it's got little to NO brakes. Was in reverse so I got it stopped but barely. Had light brakes until the pedal would go no more. (NOT floorboard but a solid hit plenty above where I know it COULD go)

I pull back up and seems like even less brakes. (I put a bigger cam in it than previous and 1st gear is stronger)

No engine codes as far as booster sensor.

So here's what I've checked.....

There are no leaks. Pedal stops solid and does not go any further anyway.

Fluid is full.

Brake booster is hooked up to vacuum.

Sensor is hooked up properly.

So could my caliper pistons be rusted shut?
Could it be the brake booster valve stuck?
Could I be in the twilight zone?

Everything went together well but this is the first hurdle I've faced. I WANT MY CAR BACK.

[motorhead]

Do you have too low of vacuum now with your larger cam? That used to happen with older cars all the time. Not sure about the gen 5 cars, but just a suggestion. If the brake system wasn't open, I can't see why there would be any problem with it sitting.

[MMX RS]

Have someone help you look to check the pistons to see if they are stuck.

I was an idiot and let my truck sit (because of the pretty good weather the last year) and froze the rear calipers. Mechanics and friends both said the worst thing for brakes is to let them sit. They are unable to clear themselves of the environment that way and can lock up.

[PQ]

I can't be sure of either. I did try tapping them with a hammer.

The feel of the pedal is weird. It will begin to pressurize and before it can quite stop solid it kind of hits what feels like a back stop. But I know better.

Cam should not cause enough less vaccum since it's not as big as some who never had a problem, however I did lower the compression ratio for the blower.

[motorhead]

It would be easy enough to check the vacuum. Usually if it's vacuum though you will get one good pump out of it before you loose power assist.

[NC-V]

I highly doubt the calipers are frozen. When most calipers "freeze" up it is a floating or sliding style caliper and it is actually the mounting hardware that seizes up. The only time I have seen caliper pistons lock up is with cast iron calipers where moisture built up inside the caliper and rusted the inside.

The brembos have neither of these issues. They are 4 piston calipers that have no slides or floating pins to seize up. They also will not rust or corrode in place due to the heavy coatings on the inside and the fact that they are an aluminum composite.

Is there a noticeable difference in brake pedal effort with the car off and car running? Also I would take a measurement of manifold vacuum just to make sure you are making enough vacuum to properly operate the booster. If you never opened the brake hydraulic system, my bet is a booster or vacuum issue, especially if the pedal is firm and doesn't drop to the floor.

[PQ]

Originally Posted by motorhead

It would be easy enough to check the vacuum. Usually if it's vacuum though you will get one good pump out of it before you loose power assist.

Actually it did get one good pump and hold but used it to hold the car while I put it in reverse. Not sure if it was a strong one really. The thing that bothered me the most is that it did seem to lose hold but it didn't drop far at all before it "bottomed out". There was a hard shelf so to speak well before the floor.

Originally Posted by NC-V

Is there a noticeable difference in brake pedal effort with the car off and car running? Also I would take a measurement of manifold vacuum just to make sure you are making enough vacuum to properly operate the booster. If you never opened the brake hydraulic system, my bet is a booster or vacuum issue, especially if the pedal is firm and doesn't drop to the floor.

There was no noticeable difference really.

I wish I could go out and check some of these but this car is loud. hahaha And it's late.

[motorhead]

Originally Posted by PQ

Actually it did get one good pump and hold but used it to hold the car while I put it in reverse. Not sure if it was a strong one really. The thing that bothered me the most is that it did seem to lose hold but it didn't drop far at all before it "bottomed out". There was a hard shelf so to speak well before the floor.

There was no noticeable difference really.

I wish I could go out and check some of these but this car is loud. hahaha And it's late.

I've had many issues with cars with big cams and power brakes over the Years. It's starting to sound like that. I use to either switch to manual brakes or install an electric vacuum pump.
Some of these cars had very High lift with very long durations. What cam are you running?

[CHMSC]

Not that it's the same but when I left my truck in Bama for a year the calipers froze up on me due to the humidity and moisture and sitting there not being used. That would be the first place I would look PQ.

[mlee]

This one sure sounds strange... Wonder if it has something to do with ABS.

[motorhead]

Originally Posted by mlee

This one sure sounds strange... Wonder if it has something to do with ABS.

Was thing that too, but that's beyond my knowledge to make an estimation on.

I would love to know the complete cam specs though.

[PQ]

Originally Posted by motorhead

I've had many issues with cars with big cams and power brakes over the Years. It's starting to sound like that. I use to either switch to manual brakes or install an electric vacuum pump.
Some of these cars had very High lift with very long durations. What cam are you running?

Originally Posted by CHMSC

Not that it's the same but when I left my truck in Bama for a year the calipers froze up on me due to the humidity and moisture and sitting there not being used. That would be the first place I would look PQ.

Once I do the easy checks I'll get to the calipers.

[PQ]

Originally Posted by mlee

This one sure sounds strange... Wonder if it has something to do with ABS.

I'm trying to think of a reason it would mess up from sitting.

What sucks is start-up was perfect. No leaks, no hesitations, no nothing.

[mlee]

Originally Posted by PQ

I'm trying to think of a reason it would mess up from sitting.

What sucks is start-up was perfect. No leaks, no hesitations, no video, no nothing.

Let me fix that for you..

Sucks about this brake deal. I'll go find some experts for you.