You have to have air in the system if fluid is not coming out...

The system works by reducing the cylinder volume on the master (when u push the pedal) and increasing the volume (expanding the piston) on the slaves/calipers. The slaves have to move due to hydraulic forces and are only limited by fluid compressibility, which is not much at these pressures. You have air my friend!

 

i have bled the **** outta my car though. thats exactly what i dont get.

 

if you disconnect (or loosen) the fittings from the master to any front brake line... Have a helper step on the brake pedal carefully - see if you get air or fluid out of the master. I will bet air with fluid. Either the front piston or rear piston is seeing air in that master.

And remember, most brake fluid can remove paint - so be careful

 

Hold on here! If the rear shoes were soaked with brake fluid then that tells us two things:

1. You are loosing brake fluid.
2. The wheel cylinders are shot.
3. You will never be able to properly bleed the system until those cylinders are replaced.

Why are you still trying to troubleshoot this issue, when you have already found the culprit? Replace those cylinders, then bleed the system again, and you should be all set. Good luck....

 

Nice catch Kentetsu - I missed that....

 

THANK YOU KENTETSU AND SCOTT. I will buy new ones and change em this weekend and re bleed the system. I will update this thread also. One other thing if my power booster would go bad how would i know. any thing physical or sound that could mean its bad? thnx and i checked mine out it checks out ok, vacume works along with rod and boost

 

see if it holds vacuum. mine doesnt. it leaks vacuum from the front, where the master cylinder bolts.

it still basically works as a brake booster, it holds enough vacuum for that

 

yea checked it its good

 

If the booster fails, then the pedal would be very hard. But the brakes would still function as long as you really stood on them.

I think the wheel cylinder rebuild kits I ordered from Rockauto were like 4 bucks each. Dirt cheap. Its only a couple of little seals, so very easy to rebuild them yourself and save some money...

 

wow thanks ill look em up

if the new wheel dont work orf fix my problem any other possibilities?

I have done-

New master cylander
bled brakes a million times different methods
powe booster ok
no leaks of or around line

minimAL BRAKE LOSS
possibly busted/leaking wheel cylanders

 

Replace your seals and you should be fine...

 

wich seals?

 

The seals in the brake cylinders, I'm betting. I did mine back some years ago, made a huge difference. They were sucking air even though they were not leaking noticably.

Doesn't take a lot of air to really louse up brake performance.

If you got old rubber brake hoses, check them for cracks, too. Likewise swelling. If the hose can expand when you're on the brakes, the pistons can't exert any force.

 

oh ok thanks dude

 

Mr Chew...
In one of your posts, you said your rear wheel cylinders were leaking fluid, Kent said to rebuild/replace these (or put rebuilt units in), that is the answer to your question regarding which seals.

In your prior posts, you said you bled and bled but you weren't losing fluid (when later you said you saw wet spots on your rear drums. This is a hard medium to give exact answers to and requires your care in what you say. If you have replaced and properly bled the master, all fittings are tight, and you REALLY have no leaks, such as what you currently have on your rear slaves, and you have cleaned/greased all required slide points, put on good straight pads and rotors, then your brakes will be fine.

Scott

 

thanks scott

 

Sounds like your problem is going to be fixed as soon as you either get new rear cylinders or rebuild them. Chances are if this has just happened then you may not be able to really notice the loss of fluid at the reservoir. When brake fluid leaks out it tends to look like a lot more than it is, and it only takes a little leak to wreak havoc on the entire brake system.

 

And we can't wait to hear Mr Chew that your car CAN STOP like a new car!!!

Scott

 

between the brake pedal and master cylinder, there is the adjustable screw rod that gets frequently overlooked. Sounds like when you press the brake pedal, the master cylinder moves only a fraction of what it needs to move.

Might be it needs to be lengthened or screwed out or adjusted out.

Tricky little devil.!!

If there is air in the brake line, you can tell by pumping the brake pedal several times.

If it is the rear wheel cylinders, the inside of the drums with be a mess from the leaking brake fluid.

 

Thanks again to you all, you all have been very supportive in the dilema im stuck in. I cannot wait for this weekend XD. I will keep you all updated!

 

**** im getting tired of this BULLSHIT!
well i rebuild the wheel cylanders on both wheels and they work perfectly. but when i started bleeding my brakes my two front tires will not squirt! a dude told me that there might be so mu8ch air in the front lines that it wont squirt so he told me to 1st open bleeder valve then push brakes and hold, then close valve . that did make then brake squirt but when i bleed them by pressing brake pedal 1,2,3, hold , open bleeder valve, wait one sec, close valve, let go of pedal, it only oozes out but NO SQUIRT! why is this happeneing. i thing im going to buy a new power brske booster and new brake master cylander. any ideas?

 

In your shoes, 'd try vacuum bleeding, though I've never seen a system with so much air that the master couldn't get a squirt thru after a few dozen bleed-squeezes. The lines are small; they don't hold that much volume.

Does the fluid level in the master drop? Are you careful to not let it go dry while bleeding?

It's not the booster; that's why you bleed brakes engine-off. Brake fluid never gets near the booster.

Master may not be pushing fluid.

Proportioning valve could be failed/blocked (VERY rare - never seen it happen).

Line may be plugged.

There's really not much else TO a brake system.

Reservoir
Master cyl
Proportioning valve
lines
hoses
cylinders

That's the whole hydraulic side.

 

Try installing the bleeders that have the one way valve in them. You can get them from Rockauto if nowhere else. You probably have a blockage in the current bleeders. Maybe you could remove them and clean them out with a thin wire or something, but not sure.

If you completely remove the bleeders, and still get no fluid out when pushing the pedal, then replace the master cylinder...

 

I've seen that happen, when the lil rubber caps get left off the bleed screws; they fill with road crud, then rust.

 

I was always taught as a mechanic at various shops, that you shouldnt pump the brakes when bleeding since it just agitates the air into smaller bubbles in the lines, thus making it harder to get it all out. Like when you shake a bottle of water, you get lots of little bubbles instead of one big bubble for instance. Then, once it settles (after youre done trying to bleed them), all the little bubbles just form back into one big bubble again.

I do the press, open valve, close valve, release method with a helper and always have had great luck with it on tons of different types of systems. Also, use clear hose when bleeding so you can see the bubbles coming out, and make sure you put your bottle above the bleeder (or at least the hose going uphill directly off the bleeder screw), this will help also. Be sure you bench bleed any new master cylinders you install as well. Another thing I have learned is rebuilding wheel cylinders typically isnt worth it, even if you hone them out correctly and everything, which most people dont do.

Vacuum or pressure bleeding is a good option if you are alone. I prefer pressure bleeding as its usually easier to get the bleeder to seal on the master cylinder than it is the hose on the bleeders individually. This is due to the air leaks Ive seen at the threads of the bleeders when under vacuum. You will get a stream of constant bubbles in the hose under vacuum if this happens. When under pressure, you dont see those bubbles because the fluid will be pushed out the threads instead, so it will possibly leak a little during the process, but it wont look like theres still air in the system. When you're trying to pull the fluid out under vacuum, if you have those air leaks, you wont get the full vacuum on the line due to the leaks around the threads, so its less effective in "pulling" fluid out of the system that way as well. Think of if you covered the end of a shop vac with the palm of your hand. Good suction. Now move it to where your fingers are. It will suck air between your fingers and not put the full force on your hand. Same concept really.

I built a pressure bleeder for less than $20 with a small garden sprayer pump bottle, a spare master cylinder cap, and some fittings and hose from the hardware store. No need to pay tons of money for one. The way I built mine, I can change the cap on it to use it on multiple different master cylinders for my cars.

Oh, and dont forget some brake cleaner. You need to clean those rear drum assemblies and everything up real good. Brake fluid all over everything wont help your problem when the pads are soaked and slippery. Also, make sure the front calipers are working correctly and arent siezed, and try and replace the bleeder screws on them if theyre looking nasty and possibly clogged. My local Napa and Car Quest both have bulk bleeder screws I can pick through in a parts bin to find ones I need.

Just some things off the top of my head. Hope you get it going soon!

~T.J.