raffaplymouth

hi , i have installed now a kit with front disc drilled and caliper Wilwood 4 pistons on my 1970 Barracuda , factory brake is front disc with single caliper and rear drum , the problem is the car brakes less than before !!! , master cyl is factory Dorman 1.031 diameter , rebuilded brake booster , rear drum 10" with new shoes and new wheel cyl .. i have installed also wilwood regulator on rear brake ... nothing ! no brake !! pedal is hard and not brake !! help me !!

Drag Pak

Do you still have the rear outlet from the master cylinder going to the front brakes(normal)?

raffaplymouth

yes connected like stock brake

Drag Pak

How is the vacuum at the brake booster? Try removing the master cylinder from the brake booster, and see if the pedal is still hard.? May be a bad brake booster rebuild?

raffaplymouth

good vacum ! i have electric pump !

RacerHog

Raffa,
What Disc pads did you use with the system?
Also Did you up grade the Brake line Flex Hoses?

TVLynn

Did you install the calipers correctly ?? Bleeder screw on top

raffaplymouth

Yes Bob ,wilwood stainless brake hoses , wilwood brake pads .. bleeding upper ... car doesn't brake .. this car never brake also with single pistons factory caliper . this morning i changed also the proportioning valve ... no change .... i have also vacum electric pump

RacerHog

Raffam
Look at the steel lines and make sure they are not pinched. Sometime one gets pinched or gets a kink and someone dose not catch it.....

RacerHog

Also Pressure test the system at the caliper with a gauge set.....
Should be some wear between 700 - 1500 PSI up front.

Drag Pak

How is the pedal travel while bleeding the brakes?

raffaplymouth

pedal travel good , all line is new ! tomorrow i will check the pressure ! with engine started ?? if pressure is low ?

raffaplymouth

i have 70 challenger with the same brake system and brake perfectly !! i dont know this !

raffaplymouth

look like the car stop only until 40 mph ... after no stop good !

RacerHog

If pressure is good......
Try a new set of lining.... We have been having problems with MFG changing the compound of the make up of the lining and not stopping....
Some have a sign of a spongy pedal but others just say it will stop but takes allot longer......

At first I thought this was your car? Now I know it is a customers car.... The Red Car..Now I get it

raffaplymouth

Look like very hard to find this issue ....anyone have already installed this dynalite wilwood kit ??

RacerHog

Pressure was good ?

Drag Pak

Some thoughts/questions

Were the brakes bled furthest to nearest the master cylinder? ie., rr > lr > rf > lf?

Is the master cylinder/power booster pushrod releasing enough to allow the master cylinder piston to clear the vent hole?

Is the master cylinder/power booster pushrod travel sufficient to fully depress the master cylinder piston? (pressure test will tell)

Was the master cylinder sufficiently bench bled?

Is the master cylinder correct for front disc/rear drum application?ie., no built in residual valve for the front disc.

raffaplymouth

Drag Pak

vent ??? i dont know ! please show me !

When you look into the fluid reservoir you should be able to see the piston move past (to the rear of) the vent/fill hole in the bottom of the reservoir. If it (the piston) is uncovering the vent/fill hole, you should get fluid spraying up (messy)when you release the brake pedal.

yes blended 3 times

My manual master cylinder took about thirty(30) fulll pedal pumps to (bench) bleed.

raffaplymouth

I have blended another time ..i have cheched the vent .. All is ok but the car doesnt brake ... I checked the line pressure on caliper is 1200 psi with vacum applied and 700 without vacum ... Checked also disc to calipers allignement .. Nothing .. Pedal is hard and car doesnt brake !!!! I see after 4/5 brakes .. The rotors are not very hot ...

RacerHog

Try a different set of pads.....

raffaplymouth

Bob i tried now to remove the pads ... Look like glazed ... I have cleaned with sand paper 80 .. I tried to remake the break in .. Is a little bit better ... But not efficently

TVLynn

Try different pads. Maybe they need to get hot before they work

RacerHog

Thats what I'm getting at... Maybe the pads are damaged... Ceramic sometimes will not come back.... (Christilized)??? pads are no good no more.

Drag Pak

Are the calipers centered on the rotors?

Is there any brake drag?

raffaplymouth

Guys .. problem solved !! WAS THE BRAKE BOOSTER FAILED !! ( BUY ON EBAY REBUILDED 4 YEARS AGO !!))

raffaplymouth

NOW I HAVE INSTALLED THIS !

http://www.ebay.it/itm/200962698010?...84.m1497.l2649

IS DUAL 8" ... BRAKE PERFECT !! NOW IM UNDECIDED IF INSTALL OR NOT THE REAR DISC CONVERSION THAT I HAVE ALREADY BUYED FROM ssbc

RacerHog

Wow...That's the 2nd Diffective Booster with in a week that I have heard about..... CRAZY....

Glad you found it..... So what was really wrong with it was it had "No Assist For braking"....

Thanks For the update Raffa.... You Rock !!!
By the way.. I love that White Chrysler you posted.... Awesome

raffaplymouth

Yes Bob was Brake Booster diffective !! now brake is perfect ! yesterday i have check the pressure with new gauge .. is 1300 psi on the front and 1300 on the rear ----- look like ok ... thanks for your help