help hard break pedal weak breaks after swap

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chubsgts

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i went to power kelsey hayes breaks all new master is 1 and 8TH bore
new booster bought as kit from right stuff
all new lines every thing

bleed breaks fire car up started going thru check list on every thing sense whole car is fresh
noticed pedal is nice and high but seems a bit stiff and not much stoping power and the brake system light light will come and go as im trying the breaks in gear slow roll hits of the breaks in drive way


i did swap out the distribution valve from a disk break car and it came with the secondary prop valve that goes further back on the rear line but did not install it
im not sure if i may still have air some where in system or if i should just installed a adjustable prop valve from summit
 
Hard pedal and bad stopping power.

I say you have a restriction in the system. Was the distribution valve, used or new?

Do you have the vacuum for your booster hooked up correctly?
 
valve was used but looked very nice

only one line on booster to hook up and its hooked to rear intake runner driver side where every one said to run it
adjusted the rod end to meet the pedal when installed so should be no preload there
car rolls perfect when pushing it n neutral so i wouldint say theres any drag

all new rubber lines two

i wonder if i should install my old distribution valve just for the heck of it and see what happens but that was from a drum break car
 
A hard pedal has nothing to do with bleeding, this indicates that they are BLED JUST FINE

Hard pedal, poor brakes:

master too large bore

booster bad or not enough vacuum

restriction in line(s)

shoes not properly fitted to drum (drums turned out too large, shoes contacting only center of drums, lining glazed due to this, shoes need "arced" etc )

shoes/ pads glazed, not properly broken in, wrong material

Some time ago someone posted some info, I think from year one, on the various types of metering/ switch/ distribution/ combo proportioning valves used. I would think that there is room for trouble in these, things like or rings deteriorating, etc
 
well like i said its all from right stuff all of it so if the booster master or any of that is wrong they must not have any ideal on breaks and i hope they will correct that
i remember every one saying 1 1/8 is the correct master i didnt order to that size thats just how they sell it so maybe one inch is it

i have to go check my vacuum and go from there
also the brake system light comes and goes so all the tech guys at right stuff says thats master related air in lines or faulty master


hoses pads shoes hardware rotors drums ALL is new
drums are right where they should be slight drag sound to them when spining the wheels faintly hear it so they shouldint be over or under
 
I went through this. I have 74 disks on the front of my 67 Barracuda and 74 11X2 1/2 drums on the rear.I orginally had a 1 1/8th bore master cyl and very hard brakes. I dropped down to an smaller bore master cyl. I found a 7/8" at Carlisle and swapped it out. After a lot of bleeding (you'll have more pedal travel) I finally got it right. Mine are manual brakes and do stop well, but it does take more pressure then your power brakes. This year I want to play with a adjustable proportional valve to the rear drums.
 
well after fighting with the gear box fitting to stop leaking i looked into breaks heres where i ended up
checked vacuum i do have 18 pds at idle so that's good checked the valve at booster that's working
bleed front breaks small amount of air did a little back and fourth in my drive way no more brake system light

still have have minimal stopping power i cant even lock them up from a 10 mph roll and hammer them calipers came from a buddy said they were rebuilt pistons are brand new you can tell just by looking at them so i really have no reason to doubt him

pedal also seems very high i noticed like 3 inches above gas pedal don't know if that helps at all in the problem i don't remember it being that high

could the rear drums be adjusted up to high even thou theirs no drag on them causing pedal to be up high and not having enuff pedal travel >mechanical leverage<
causing the rear shoes to be slammed against drums before my front are really even working if so i would think they would lock up and i have no signs of rear drums adjusted to tight no dipping in the rear grabbey effects or any thing
 
chubsgts said:
could the rear drums be adjusted up to high even thou theirs no drag on them causing pedal to be up high and not having enuff pedal travel >mechanical leverage<
causing the rear shoes to be slammed against drums before my front are really even working if so i would think they would lock up and i have no signs of rear drums adjusted to tight no dipping in the rear grabbey effects or any thing
Click to expand...

NO

Only thing shoes "too tight" might cause would be rubbing so hard they generate heat while driving, glaze and "heat fade" the lining.
 
talked to right stuff again today they seem to think the brand new booster i got from them is junk so after i had it painted and all the crap now i need a new one to replace my new one thats 3 months old

o yea sir there on back order
WELL jeeez thats really good


so will see i dont really know if thats the issue i guess its worth a shot when ever it shows up im finally ready to drive the car and cant BULL $hit so tired of companys selling junk and i seem to get it all on my door step
 
that stinks chub's... at least they are trying to make it right. how long did they say its gonna be to get you'ze another one?
 
I can almost guarantee its a bad booster. For over a year now, I've been getting lots of calls about poor braking, and so far every time its been a brand new aftermarket booster from any number of suppliers. A bad run I guess, which also explains why they're back ordered.
 
ya rod was changed came with kit

who knows on how long 4 weeks atleast

i know the booster is a 8" dual diaphragm looks like a bendix not sure just wondering if they will give a littel more info and i can track one down my self send mine back and get a refund see what you get when u spend 300$ trash lol


Bill reilly

you got knowledge on this brake stuff if i send photos or do you know what booster they use


chubs
 
I,ve also had brake issues in my 68 Barracuda.I went through the whole system and everything is fine.I put a vacuum tester on my booster,had 20lbs in neutral,put in gear and it dropped to 15lbs.I still had a hard peddle and minimal stopping power.I took the booster off(rare 7 inch)and took it to Brake speacialist last week.I think it,s like $380 to rebuild,but would sell me a 9inch with M.C for $370?WTF?I called today,they still haven,t looked at it.Good luck.
 
i just bought the whole set up so they will cover it or i would be very pissed to spend another 350$ for a rebuild and i wish i could have found a org one
 
It hasn't been one particular booster - I've seen the small duals and the bigger singles bad - dozens of them. It seems more that some reman factory had a bad process and didn't know for a long time, so there's just a big pile of bad ones floating around. The only way to buy an old style booster and be sure about it is to use one of the restoration shops that rebuild them in house... But its a pretty expensive service I'm told.
I don't think there's any way to track or id a particular run of them to know which are the bad ones, so its a crap shoot. I guess if they're cheap enough and the seller makes good on it, then its only a matter of more money or more time... Then again, isn't everything I guess...
 
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