CJ5 brake help

[beauchamp]

did complte brake job , new caliphers, pads, bleed brakes, new master clynder, and brake booster. repaired vaccum lines as close to the book layout as we could figure. still hard pedal to the point i dont want to drive on road. we have adjusted the brakes all the way out.
Previous owner replaced the cabruator just prior to sale.could the vaccum line going to wrong port be cause of problem.I am baffled.

 

[superj]

No help here. I have never had a hard pedal problem on a jeep. The vacuum booster comes off the intake though, not the carb, on all my vehicles

 

[beauchamp]

thanks, the vaccum does come off the intake but there are hoses from the canister that are not connected, and ports under carb with plastic caps.

 

[TLCJ5]

Not sure it would cause your problem,but did you bench-bleed the new master cylinder?

 

[beauchamp]

yes and after all that checked out removed the master, checked out the booster then reinstalled and re bled.

 

[69jeepcj]

You want the booster to have full manifold vac. if the vac lines at the carb you mention are on the wrong port it will not provide full manifold vac. I have read your post and can't figure why you have a hard pedal, other than the booster isn't getting the vac needed.

Your brake lines aren't switched at the master are they? front line screwed into the rear, and the rear line screwed into the front? Not sure that can even happen though, just a thought.

 

[greg92jeepxj]

This does sound untypical since you got many new parts but are you using he old brake booster check valve ? Rarely , they go bad and don't let vacuum through. Could try swapping it with one that fits from a vehicle that is know to have no issues with its power brakes . As long as the check valve fits the rubber grommet on the booster and the vacuum hose , most are the same , this ought to tell if the booster is getting proper vacuum as long as the manifold tee is not blocked and feeds vacuum. Hey , is the brake pedal push rod in proper adjustment ? They're supposed to be checked when boosters are swapped. Usually the one from the booster to the master is ok but you'll want to be sure the one from the pedal to the booster is ok too . Better yet , since it's an issue , both should be checked . A good manual will have the specs .

 

[beauchamp]

I have given up and taken it in to a brake specialty shop. I will post what he finds I hope it is simple. Thanks for the help

 

[beauchamp]

wel I now have brakes, 368.00$ the new booster was bad, along with a new exhaust complete from manifold to rear.
a front end alignment and onto the trails.

 

[greg92jeepxj]

wel I now have brakes, 368.00$ the new booster was bad, along with a new exhaust complete from manifold to rear.
a front end alignment and onto the trails.

sorry for the high dollar repair bill bur at least you did get a full exhaust system out of it.
Well , we learned something today , we can't always trust new stuff and that means we always have to further our diagnostics and follow through to verify that the new part we just assembled must be checked for proper operation. Real shame that a new part put you through this but happy you can drive your jeep now ! :verry-happy:

 

[beauchamp]

you said it right never overlook obvious

 

[superj]

At least you are good to go though, Thats great.

I have oldie manual brakes on my cj5