help! no brakes

[onthebus13]

I recently did a 4 in. lift and replaced the stock front brake lines with rough country lines, I rebleed the brakes and they worked great for about 50 miles. I was driving down the road when the petal went to the floor . no brakes. I went home rebleed again but no luck, I also checked for leakes and couldn't find any.as soon as i start the engine the brakes go to the floor, when i turn the engine off there is pressure but not much, I suspect the power brake booster might be out, but i'm not sure. when i remove the vac from the booster to the carb there is no pressure in the booster but there is plenty of vac from the carb. Anybody got any ideas? or has anyone ever had the brake booster go out? help, i'm stumped.

 

[SteelHeadz]

If the brake booster fails, the only thing you loose is the power assist. You will still brakes but it will be hard as a rock when you depress the brake pedal. Make sure that when you bleed the brake system, start from the wheel closest to the master cylinder to the farthest. If the pedal still goes to the floor, i would suspect that your master cylinder is faulty due to a piston bleed thru.

 

[89 jeep yj]

I've always started with the farthest wheel from the master cylinder. I wonder if one way is better than the other?

 

[xt master]

must start with closest.Starting further away then moving closer can cause air bubbles in the line stopping the brakes from working.

Should be front driver,front pass,rear driver,then rear pass..As long as your booster is on the driver side which it should be.

 

[89 jeep yj]

I truly am tring to find out which way is better. If you google( bleeding brakes on a jeep ) the first three articles all say start with the farthest. I have always done it this way. If you have always done your way , what's the differance? They both seem to work.

 

[unclebill]

the FACTORY SERVICE MANUAL says.
bleed wheel with longest line from the master cylinder first.

 

[volaredon]

yup; technically Ive always heard farthest 1st; but in 18 years of being an alignment/brake guy I found that most times it didnt make a whole lotta difference! Check to make sure a caliper didnt come loose, pad didnt "slip out" etc; did a "side job" on a neighbors car (non Jeep) last weekend 1st drive the pedal went almost to the floor; I re checked my work and found that though the caliper bolts were in correctly; the pads didnt slide all the way into the grooves in the caliper bracket, so the pad was "flexing", making it seem like the system was "air-bound"; which made NO sense, since I never opened up the hydraulics on that one. Did you lose a bolt so the caliper could flop around behind the wheel??

 

[firedude]

I have bleed furthest first for many years with success. Not sure it makes a big diff. Are your new lines braided? Sounds like a leak. It can be very small. You could install the old ones just to eliminate that as the problem.

 

[spyder873]

I know this sound silly but.... Do you have the calipers on with the bleeder up? Don't laugh.... i have two friends who put them on upside down already. bleeder up?

 

[onthebus13]

I was going to start by replacing the master cylinder, but i decided to check the rear cylinders to see if they were leaking . When i pulled the passengers side drum the rear brakes fell right out. the adjustment parts were all disconnected . I'm going to rebuild the entire rear brakes and try to re bleed the system, if that doesn't work ill replace the master cylinder ,Thanks for al the advise . Im going to try re bleeding, starting from the closest one to the farthest to see if that helps.

 

[89 jeep yj]

are you kidding. good luck

 

[mud4feet]

.........When i pulled the passengers side drum the rear brakes fell right out. the adjustment parts were all disconnected.........

I think you may have found the problem!:shock::roll: