Bled brakes today, ran into an issue.

I want to pre-apologize for this answer.....

Your wife is a better bleeder.

Please accept my apologies. I could not resist. I feel better now.

 

I have experienced the same thing. That is but one reason I don't like motive bleeders. If I can bleed motive style or 2 foot style and get a rock hard pedal then it does not matter which I use. The only time I ever pressurize motive style is when I have to work by myself. The motive will only put 10-20PSI (I forget the psi) at the gauge. Your foot will put hundreds of PSI so the obvious answer is that you got some partial blockage like atherosclerosis that is not overcome by the low motive pressure. If you start your car and bleed the brakes with engine running you will find fluid will come out even faster than with engine off. Typical blockage areas are the bleeder itself, the exit of the caliper, failing rubber brake line internals. Regular at least annual fluid change goes a long way in preventing problems.

 

That's what I do with the track car and all my cars. Yes I have the Motive pump too. It does the same thing. A waste of time IMHO. Unless you happen to have failing hoses and that happened to me two years ago on a 40 year old car, shocking I know , then it's probably easiest solved with the two person drill.

 

It sounds like even after using higher pressure bleed method, it still dribbles indicating a system flow restriction. If you have a system flow restriction, firm petal does not translate to proper brake pad pressure and full performance.
If you have a half restricted left rear caliper and a restricted right front even after getting clean fluid, isn't there still a problem to be fixed?
Looks like the low pressure bleeding just shows you there is a problem.

 

I had an experience on a 360 in which there was blockage in the hard line connecting the two halves of the caliper. Strange but true.

 

Not if this statement he made is true...

If this statement is true I'm not concerned by a dribble at 12psi. I think I can blow through a straw harder than that and would not expect much flow though a bleeder with my lung pressure. It does not take much plaque at perhaps the exit of a bleeder in a perfectly acceptable location to look like a flow restriction. The OP also did not remove the bleeder and clean it or the caliper exit the most obvious and likely place for restriction.

 

This is an important step, recall that brakes are power-assisted....

 

Chris are sure that when you pump the pedal you don't get the normal flow from the nipple? Even unassisted, pumping the brake pedal should have adequate flow to the caliper. I'm imagining it *could* be possible that at the ASR unit one of the actuating valves is closed and needs cycling. When you pump the pedal (even with power off) does the flow improve?

If there were that sizable obstruction upstream from the caliper.. I can't see how you wouldn't have less wear on the pad and issues with braking...

 

Just be careful bleeding the brakes using the pedal as it can damage the master cylinder if the pedal is push too far down.

 

That is really untrue of well maintained systems but seeing that many are not maintained well you are right. For those who do not know Voicey is referring to the problem of scale junk building up past the maximum limit of master cylinder piston travel under normal braking events. This junk builds up there because nothing ever swipes through and cleans the area. So if you got a bunch of junk in your MC and floor the pedal during a bleed you can scratch the rubber seal on all the scale then it will not seal well in the smooth area of normal travel. If that happens you loose your brakes or have a spongy traveling pedal. The old school trick was put a piece of 2x4" behind the brake pedal to prevent full travel. The problem was you never knew what the normal travel really is so the 2x4 might still allow more travel than you want.

So if one is a hamfooted pedal stomper the pressure bleeder avoids this whole issue because the pedal is never pressed. At the end of the day it is like my signature below.

 

Ahhh interesting.. and that's why rifledriver doesn't like the vacuum bleeding either.. ahh!

 

You could check the pads for uneven wear yes? Finding that would indicate a problem in the calipers

 

OK then did you put a wire the diameter of the hole into the caliper? Remember poking a wire through is the problem with snaking a drain. The plumber can always snake the drain but if his tool is not the same diameter or opens the same diameter as the pipe you can't get it clean inside but you can poke a hole for some drainage and push the dirt around inside.

Sometimes if there is enough junk in there you just have to take the caliper off and open it up and clean it and that means new seals and cleaning any L R bridge if any AKA rebuilding the caliper.

 

Not sure what you meant here. I always vacuum bleed brakes with rarely a problem. Pressure bleeding comes with the risk that brake fluid comes squirting out unexpectedly. I saw a 275 that needed the hood repainted because this happened and nobody noticed until after lunch.

 

If you want to understand why 2 person bleeding always works better then using a pressure bleeder, just read up on how a master cylinder works.

 

"The fluid that came out initially was very dark and contaminated looking."

Your descriptions indicate a breakdown of the brake system's rubber hose(s).

 

sounds like clogged calipers -- remove lines from caliper and make sure they bleed then you may need to rebuild the calipers with new transfer lines then powder coat.

this is common on cars that don't have brake flushes yearly which is why the dealers always press to do them - always cheaper (brake flushes) than a brake system rebuild

 

Chris,
If you feel you have safe brakes then please, enjoy your car. I would be interested to see if the flow with a pressure bleeder is now equal. While driving, the amount of fluid movement in the caliper is close to nothing and it does not cycle, so whatever is there now will be there after driving, flushing is the only chance to "move" anything around and hopefully out.
I have had to use foot pressure to move obstruction from lack of bleeding and I always just left the pressure bleeder installed and checked it afterwards to verify I had no more restriction. I have only had to remove one crossover tube that would not clear.
Also, uneven brake pad wear could take a really long time to see any difference.

Yearly brake flush is very important to maintain safe performance.