Brake bleeding problem, I'm stumped

I'm stumped on doing disc brakes on my 60 Chevy. I've put discs on my 51 and I didn't have this problem.
Here is the situation,
New disc brake kit, new master, and front brakes. I bench bled the master until no bubbles, put the master on, attached the lines.
The rear drums (old) bled fine, the front calipers won't bleed.
I can pump and pump the brakes and when I crack the bleeders on the calipers I get NOTHING.
I had a few small leaks where the flex line attaches to the caliper but I am getting nothing at the bleeder.
Yes the bleeders are on top.
Anyone have this problem???

 

can you put the pressure check valves in backward? Have you bled evey connection up to the calipers?

 

discs take "forever" sometimes - I'm not sure why - I just attributed it to the ginormous increase in volume of the caliper.

One way to deal with it is to use a pressure bleeder.

I've also had sucess using a ginormous syringe and literally ****ed the fluid through.

I've also done front discs by putting a piece of hose on the bleeder and done the process "normally" (pumping the brakes) but left the bleeder open and just used my thumb to "close" the system remotely via the hose.

 

I just ordered the summit bleeder kit so we'll see if that helps. I dont' remember the calipers on the 51 taking so long to "fill". I know I'm getting fluid to the flex line because it leaked a bit. But now that I have no leaks it just seems to not be doing anything. Funny thing is the rear line has more new brake line and the bled like a breeze.

 

Sometimes tapping on the caliper with a small hammer helps, take the bleeder screws out and let it sit for an hour or so with a drain pan under em, fluid will come.

 

Sometimes when I dont have any help I just fill the master (keep checking it) and leave the bleeders open until it runs out. Might be worth a try.

 

Copy cat! Ha!!!

 

Aaron - Open the right front bleeder, put a tray under there to catch the fluid, and let 'er gravity bleed (it is a firewall mounted m/c, right?). Once you've achieved flow on the right, close the bleeder, then gravity bleed the left. I know this takes longer, but if it won't gravity bleed, there is an obstruction; then you can trouble shoot it line segment by segment by cracking the fittings and verifying flow as you go from master to caliper. Once gravity bleeding succeeds, pressure bleed via the pump-the-pedal method. Patience and a logical sequence of troubleshooting will allow you to succeed. vic

 

Sounds like you have a brake light safety valve in the system and the Barrel valve shifted and shut off the front lines. They are designed to do that when Hyd. pressure is un-even.
The Wizzard

 

Question for Aaron51chev! Is your Master a single or Duel ? Ter409

 

As mentioned before, sounds like you have an obstruction somewhere. Brake bleeding is pretty basic, if you think about it.

 

Start at the m/cyl. Does it bleed at the front brake line fitting? If not fix or replace the m/cyl. If it bleeds there, follow the line bleeding each fitting as you work your way down to the calipers. When you find a fitting with no fluid you've found where to look. I've found bleeder screws that were never cross drilled in rebuilt caliper boxes. Don't ***ume anything.

 

Check the travel of the piston in the master cylinder. You may need to adjust the linkage/push rod to add more movement. I had a similiar problem on a completely different car where the travel of this piston was not as much as it needed to work correctly.

John

 

sometimes i blow compressed air thru the ventilation hole in the cap (low pressure).
When a friend loosen the bleeder screw, Takes usullay 10-15 sec to bleed one wheel.
Keep an eye on the fluid level.

 

Is the pedal spongy or firm??? If it's spongy then I think it's just a matter of persistance. If it's hard then I think Pist-n-broke may be onto something.

 

Check to make sure you have the calipers on the right sides of the car...some calipers will interchange side to side....and it will place the bleeder valve on the bottom of the caliper...it should be on top to allow the air out!

Just a simple mistake I have made before

--reed

 

Question??? Do you have a brake safety control valve, Large br*** block where all lines connect from Master Cyl then split off to front and rear wheels?
The Wizzard

 

I don't have a saftey control valve, no large br*** block in the system. I gravity bled the left side for an hour and nothing came out. The master is on the firewall. I'll try to gravity bleed the right side, before the caliper and then to the caliper and so-on.
I thought it was a blocked caliper but both calipers are not bleeding. The pedal isn't firm, easy to push.
I did check the travel of the master, what I did was to connect to small lines to the master and bascially bench bleed it on the car, there was fluid moving through both lines, so I think the travel is ok. I have since rebench bled the master.
Thanks for the help so far, off to gravity feed each connection.

 

Update,
So I realized I left the bar in place that I use to hold the brake pedal down when I bleed brakes on my own, so that wouldn't let it gravity bleed right?
Anyway, I did start at the master cylinder and cracked that fitting and fluid came out, I also did it at each fitting going to the front right caliper, each time fluid came out. I pumped and pumped and still nothing out the bleeder on the caliper.
So I took the flex line off, and blew out the fitting and it's clear, then I shot a puff of air into the caliper and it came out the bleeder screw so it isn't obstructed.
Also while the flex line was off, fluid was dripping out of the caliper so maybe it is just time? Anyway I'm gravity bleeding that line right now and we'll see if it starts to drip or not.

 

That really ****s man, I'm going to put discs on my car next week I hope and I sure appreciate all teh brake bleeding advice, cuz I'll probably need it. This time I bought speed bleeders all the way around so I don'thave to rely on someone helping me. I bought the little cup wiht tube basic brake bleeder from jegs, but that vacuum pump one really looks great.

 

Make sure your your rubber boot that stays attatached to the master clyinder cover is still attached to the cover. You may have left it on the master cly and by mistake poured brake fluid in it causing it to expand. Once that happens it is hard to tnotice it. The cover would act like a pool liner and prevent fluid fom getting in the system.

 

Sounds like you are on the right track. I have a suggestion:

Put the brake bleeder hose into a jar filled about 2" with clean fluid and try bleeding. You obviously should see bubbles in the jar. If no bubbles and the pedal is still soft then there might be a chance that the bleed screw and bleed hole in the caliper is blocked. Since they are new is it possible that the pistons are bottomed out in the bore when they were spread back to clear the rotor? This might block off the bleed hole. Just a thought.

 

You don't say if you put new flex lines to the wheels. Some of those old ones can plug so tight from the inner lining going bad that you can't get anything through them no matter how much pressure you use.

 

I had this happen to my 57 truck. Wound up taking it out of the system and got good brakes> Factory brake light safety valves are real POS when they screw up.

 

he's right,did you put knew rubber hoses on it. they will break down inside,and stop em up tighter than ****s hat band! just a thought

 

New rubber hoses, the dual master rubber gasket is intact on the master cap. I just left the drivers side bleeder open for about 1.5 hours, completley dry. So I'm still stumped, I'm pretty sure I'm getting fluid into the caliper, not sure why it's stopping there. Hopefully the summit bleeder kit will help.

 

Sounds as if that caliper may have been ***embled incorrectly-

 

Is it air in the lines, or does it need a residual pressure valve to keep the pad pushed out to the disk. I had a residual pressure valve stick open this year and had to pump the pedal twice at the end of the straight to have enough rear brake to set up for the turn. I had great brakes once I got the pistons pushed out of the caliper.

One way we bleed the brakes is to crack the bleeder then push the pedal down. Then tighten the bleeder before letting up on the pedal. This does two things, it really moves the fluid through the lines and it pushes the old fluid out. With the high heat from racing and weekly pressure washes the fluid absorbs moisture, so it should be changed periodically.

 

Double A, This is how I do it. And I leave the bleeder wrench hanging on the hex before I put on the hose so while it is going, I can tighten it up before I pull the hose off.

Hope you get it worked out.

 

I was talking to a friend about it, and here is one thing I'm not sure of. The front brake lines are mounted to the front port on the master cylinder which looks larger. The instructions didn't explain which is whcih. However, when I was bench bleeding it, I noticed the rear port started pushing fluid first and the front port didn't start until I had pushed the cylinder half way. Maybe the front brakes should be on the rear port? I don't know what type of master it is other then GM.