72 camaro brake probs!!!

[SICMARO]

my pedal sucks. car slows down slowly. pedal feels mushy.

13" baer kit w/ baer master cylinder. 7" dual dia booster. LS1 rear brakes w/ adj valve.

there is no proportioning valve for the front brakes. i just came off the master cylinder and t'ed the front lines. one to each wheel.

should i had a residual valve to the front brakes? help? and system is bleed. and no vacuum leaks.

[joeljet]

verify that you've got the front tube in the right port on the master cylinder. i read somewhere that some master cyl's are reversed. i've got baers but haven't gotten that far yet. as far as routing just t the 2 fronts into the master cyl (no valves) and used the adj prop valve on the rear.

[SICMARO]

ya the ports on the master are correct. at-least according to the instructions baer sent me. it almost feels like its not moving enough fluid.

[Tom Welch]

Is the brake pushrod the correct length for the new master?

[SICMARO]

it adjustable. i have played with the length. if i make it longer wont that make the rears lock even faster??

[Tom Welch]

Maybe so, however I would try some adjustment to satisfy my quest for better braking.

[SICMARO]

anyone had this prob before? please!!!

[6'9"Witha69]

it adjustable. i have played with the length. if i make it longer wont that make the rears lock even faster??

Not if you are on the same page as the original question. The pushrod only connects the master to the pedal. The length has to do with pedal height and full return more than anything. The prop valve will adjust whether the rears lock or not.

What size tubing did you run for the rear brakes?

How much vacuum are you making?

Did you bed in the rotors?

Do you have the equipment to measure pressure at the calipers?

Did you properly flare the connectors at the T fitting to ensure there isn't a blockage at this junction?

There are many questions. Let's start with these and go from there.

[SICMARO]

The prop valve will adjust whether the rears lock or not.

What size tubing did you run for the rear brakes?

How much vacuum are you making?

Did you bed in the rotors?

Do you have the equipment to measure pressure at the calipers?

Did you properly flare the connectors at the T fitting to ensure there isn't a blockage at this junction?

There are many questions. Let's start with these and go from there.

i have a valve for the rears. its wide open. screwed all the way out.

the rear brake tubing is the factory line.

dnt know how much vacuum

bed in the rotors??

no equipment to measure to measure press at caliper.

the lines at the "T" are the factory lines so i didnt have to reflair them.

[MonzaRacer]

OK, first question what master cylinder are you running and also make sure your rear line isnt 1/4 in.In every system I have seen converted you need to remove that large line and install 3/16.
Also if your trying to run a disc/drum master it wont work.
Another thing to remember is that drums use lots of volume then build preasure and use 10 PSI residual valves.
In the case of disc they use low volume and fast rising preasure to activate. Disc usually use no residual valves or a 2 PSI.
Another thing to remember is that most people thing you need a huge master cylinder bore to make a dual disc work which is exactly backwards. You need a smaller bore to make preasure rise faster.
Several old time circle trackers/road racers told me they used small incrents of MC bore size to firm or sofen the brakes system.
ALSO smoe pads do need some sort of beding in.
OH and if you want to elimonate squeeks get some silicone brake lube and spread a thin coat on the back of the pads where they touch the caliper/piston. and any where there is caliper to bracket contact.
Had a fella come in today with an SSBC/Baer set up sqealing to be all.
My boss at my new job asked what was up and could I fix it, and it less time than it took to get the wheels off I had it fixed.
Good Luck
Lee

[SICMARO]

OK, first question what master cylinder are you running and also make sure your rear line isnt 1/4 in.In every system I have seen converted you need to remove that large line and install 3/16.
Also if your trying to run a disc/drum master it wont work.
Another thing to remember is that drums use lots of volume then build preasure and use 10 PSI residual valves.
In the case of disc they use low volume and fast rising preasure to activate. Disc usually use no residual valves or a 2 PSI.
Another thing to remember is that most people thing you need a huge master cylinder bore to make a dual disc work which is exactly backwards. You need a smaller bore to make preasure rise faster.
Several old time circle trackers/road racers told me they used small incrents of MC bore size to firm or sofen the brakes system.
ALSO smoe pads do need some sort of beding in.
OH and if you want to elimonate squeeks get some silicone brake lube and spread a thin coat on the back of the pads where they touch the caliper/piston. and any where there is caliper to bracket contact.
Had a fella come in today with an SSBC/Baer set up sqealing to be all.
My boss at my new job asked what was up and could I fix it, and it less time than it took to get the wheels off I had it fixed.
Good Luck
Lee

I'm using the master that baer sent. both reservoirs are the same size. i had used the stock line for rears before. but then i was using a disc/drum master. I'm not using any residual valves. should i put a 2 psi in the front line??

[6'9"Witha69]

If you can pump the peadl to get good pressure, and then it goes down a little later, you need a residual valve. I run 2.
The rear line need to be reduced to 3/16.
Also make sure the rubber line running from the rear hardline to the diff is in good shape. Any expansion here will cause an issue in rear brakes as well.
Brake bedding is briefly described on page 6 of the document:http://www.wilwood.com/PDF/ds418.pdf
Try to get a vacuum gauge and test engine vacuum @ idle. Since you have PDBs it is important to determine whether or not you are getting any use from the booster or are actually fighting it, causing the slow braking condition. Also, how much pedal travel is there when you are on the brakes hard?

[SICMARO]

If you can pump the peadl to get good pressure, and then it goes down a little later, you need a residual valve. I run 2.
The rear line need to be reduced to 3/16.
Also make sure the rubber line running from the rear hardline to the diff is in good shape. Any expansion here will cause an issue in rear brakes as well.
Brake bedding is briefly described on page 6 of the document:http://www.wilwood.com/PDF/ds418.pdf
Try to get a vacuum gauge and test engine vacuum @ idle. Since you have PDBs it is important to determine whether or not you are getting any use from the booster or are actually fighting it, causing the slow braking condition. Also, how much pedal travel is there when you are on the brakes hard?

It does feel better if i pump the brakes a lil. then it goes aways. so a 2 psi valve should be used in the front line before the "t". you said you run 2 valves?

the rears seem to work fine. will reducing the line help the front at all? all rubber lines have been replaced with steel braided line.

[6'9"Witha69]

I run one resid press valve for each line out of the master (front and rear).

*Reducing rear line size helps the rears actuate faster and better. Ir right now at full depression the fronts are getting 100% potential and the reasrs only 75% due to the volume of movement and not pressure, then changing the lines will allow the rears to see more pressure with an equal force at the front (my %s are only for illustration and do not come from any math I have even attempted w/o knowing all the details of your system). This then gets you to where you need the prop valve. If both are equal then you need to dial out some of the rear to avoid the car trying to swap ends during a higher speed panic stop. If I adjust my prop all the way out as you say you have done I would get the car sideways under heavy braking from 65 mph. If this isn't happening to you with that valve wide open then you are not realizing full potential to the rear calipers.
*Also verify the part number for your MC and check what diameter the bore is. With a 7" booster and that setup a 1"-1 1/16" will probably be best.
*Again, also see about vacuum. If the booster isn't helping due to lack of vacuum then it is hurting you since the probability you have a larger bore MC is high and more manual brakes need smaller bore MCs to make the same pressure.

[SICMARO]

I run one resid press valve for each line out of the master (front and rear).

*Reducing rear line size helps the rears actuate faster and better. Ir right now at full depression the fronts are getting 100% potential and the reasrs only 75% due to the volume of movement and not pressure, then changing the lines will allow the rears to see more pressure with an equal force at the front (my %s are only for illustration and do not come from any math I have even attempted w/o knowing all the details of your system). This then gets you to where you need the prop valve. If both are equal then you need to dial out some of the rear to avoid the car trying to swap ends during a higher speed panic stop. If I adjust my prop all the way out as you say you have done I would get the car sideways under heavy braking from 65 mph. If this isn't happening to you with that valve wide open then you are not realizing full potential to the rear calipers.
*Also verify the part number for your MC and check what diameter the bore is. With a 7" booster and that setup a 1"-1 1/16" will probably be best.
*Again, also see about vacuum. If the booster isn't helping due to lack of vacuum then it is hurting you since the probability you have a larger bore MC is high and more manual brakes need smaller bore MCs to make the same pressure.

my rears are deff locking up under any hard braking. will turning the valve down help at all or am i just goin to have to change my line?

summit has wilwood 2 psi valves. im sure those will work fine.

i had a vacuum leak. the check valve was bad. but i fixed that and it seems to have great pressure. but i havnt measured pressure.

[6'9"Witha69]

Put in the resid valves and turn in the prop. Adjust it in small incriments, testing in between changes, until it stops locking the rears. You will notice differences overall once the changes start.

[SICMARO]

Put in the resid valves and turn in the prop. Adjust it in small incriments, testing in between changes, until it stops locking the rears. You will notice differences overall once the changes start.

so put a valve on both lines? both 2 psi? turning the valve in increases pressure correct? thank you so much for your time!!!

[6'9"Witha69]

Turning in reduces pressure to the rear. Less pressure means they will not activate as fast or hard, which is good.

[SICMARO]

Turning in reduces pressure to the rear. Less pressure means they will not activate as fast or hard, which is good.

oh ****. well i am retarded then haha. makes sence now. yes that is good haha. ill go try that now. reduce the rears and see how it feels thank you again. ill get on line and order the 2 resid valves and get them in too.