troubelshooting hard brake pedal, very little stopping.

[CarlC]

What device are you using to measure the rotor temperature?

[cactuss4]

I lick my finger and touch the rotor, depending on how fast my finger dries and or blisters up I know the temp, within a few degrees!! I'm kidding, don't do that!



infrared thermometer, something like this one.. Pretty much a must have for track use anyways, tire temps (inflation) as well as rotor temps, although when they start to glow, you know they are working

Tory

[cactuss4]

Thanks Tobin, ya I will have the adjustable prop valve as well, they are both "I hope" en route from Wilwood.

And thanks for the correction it is a 1.12

Tory

[Ron Sutton]

Hi Tory,

I think now ... that you have rerouted your vacuum line & are using a proper 1 way valve ... once you install the 1" M/C ... you will have "good" brakes ... like I outlined in the chart. If you want even more aggressive brakes, you will want to explore a more aggressive brake pad compound like the BP-20's.

Lastly ... if you want even more braking power ... and your tires & suspension are capable ... you would go to a 7/8" M/C. Just remember, as you go smaller with the M/C bore to increase pressure ... you're increasing pedal travel.

Nothing wrong with having moderate to long pedal travel ... as it helps to you to better modulate the braking forces. But too long on the pedal travel can be annoying or even run out of travel (pedal on floor) before full pressure is reached is extreme cases.

[CarlC]

Careful when using IR guns on shiny metal surfaces, the temperatures can be a long ways off. In training I heat shiny metal surfaces to 240*F using a contact temperature probe for reference. The IR gun will read usually 125-130*. If your IR gun says 120* but your spit boils.....

They are great for tires, radiator hoses, and many dark flat colors since most IR guns are calibrated for flat black surfaces. The better guns that have adjustable emissivity settings are pretty pricey.

[cactuss4]

Thanks Carl good to know. This seems to be fairly accurate, but I'll do some more comparisons with shiny objects ": )"

[cactuss4]

Has it really been 2 years that my car has been sitting, totally ignored. Well that blows.. But I got frustrated and closed the hood for a bit.

The 1" MC and new prop valve made things worse but more so that I've got almost no pedal pressure. I'm now starting to look into the MC rod length. I think my initial setup had someone kind of shade tree piece of metal rod , but I discarded it because the new 1" MC came with a spacer and I had 2 3/8" of rod coming out of my booster when I pushed the brake pedal all the way in. I've bled the system enough, but I've got no brakes at all now.

So now it's all about the MC rod length, do I use the spacer and is 2 3/8" coming from my booster is enough, or do I need to remove the spacer and come up with a custom length rod?

Thanks and sorry for the delay

Tory

[bryant]

when you say you have no brakes at all, more detail is needed.
is the pedal still rock hard not going to the floor like your original complaint?
does the pedal feel spongy and goto the floor?

what is the pedal height from the floor statically?
did you bench bleed the new master cylinder?

are you still using a power booster?

your idle vacuum is too low for a vacuum booster to properly work. ive found that at least 17"s is needed for good power boosted brake pedal feel.

not understanding what is going on with your push rod. the final length of the push rod will determine the pedal height. does the pedal height feel correct in comparison to other cars you drive?

[cactuss4]

when you say you have no brakes at all, more detail is needed.
is the pedal still rock hard not going to the floor like your original complaint?
does the pedal feel spongy and goto the floor?

Pedal is not hard, seems to feel soft, it will go to the floor but return, it's not as if it's not connected to anything, I feel that I have to apply some pressure to push on it but there is no stopping (again I can have the car in the air, tell my son to hit the brakes and I can't manually turn the wheel with my hands)

what is the pedal height from the floor statically?



Seems to be the standard height, didn't see any difference in it's height.

did you bench bleed the new master cylinder? Yes.

are you still using a power booster? Yes, but I just yanked it all out and going to go hydro boost, tired of this vac can etc!)

your idle vacuum is too low for a vacuum booster to properly work. ive found that at least 17"s is needed for good power boosted brake pedal feel.

not understanding what is going on with your push rod. the final length of the push rod will determine the pedal height. does the pedal height feel correct in comparison to other cars you drive?

Ya I also have a vac canister that I just couldn't find a good place for it, so as I said I've pulled it all out today, ordered the proper hydroboost bracket and am starting to investigate the proper parts to buy to get it going on hydraulic pressure..

And no the pedal height didn't seem to change, felt right..

Well the new saga will start with getting a hydroboost setup in and working..

Thanks !

Tory